BNL-94287-2010 Formal Report

Proceedings of RIKEN BNL Research Center Workshop Volume 99

The Physics of W and Z Bosons

June 24-25, 2010

Organizers:

S. Dawson, K. Okada, A. Patwa, J. Qiu and B. Surrow

RIKEN BNL Research Center

Building 510A, Brookhaven National Laboratory, Upton, NY 11973-5000, USA

DISCLAIMER

This work was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, nor any of their contractors, subcontractors or their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or any third party’s use or the results of such use of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof or its contractors or subcontractors. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. Notice: This manuscript has been authored by employees of Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. The publisher by accepting the manuscript for publication acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes.

Preface to the Series

The RIKEN BNL Research Center (RBRC) was established in April 1997 at BrookhavenNational Laboratory. It is funded by the "Rikagaku Kenkyusho" (RIKEN, The Institute ofPhysical and Chemical Research) of Japan. The Memorandum of Understanding between RIKENand BNL, initiated in 1997, has been renewed in 2002 and again in 2007. The Center is dedicatedto the study of strong interactions, including spin physics, lattice QCD, and RHIC physicsthrough the nurturing of a new generation of young physicists.

The RBRC has both a theory and experimental component. The RBRC Theory Groupand the RBRC Experimental Group consists of a total of 25-30 researchers. Positions include thefollowing: full time RBRC Fellow, half-time RHIC Physics Fellow, and full-time, post-doctoralResearch Associate. The RHIC Physics Fellows hold joint appointments with RBRC and otherinstitutions and have tenure track positions at their respective universities or BNL. To date,RBRC has --50 graduates of which 14 theorists and 6 experimenters have attained tenurepositions at major institutions worldwide.

Beginning in 2001 a new RIKEN Spin Program (RSP) category was implemented atRBRC. These appointments are joint positions of RBRC and RIKEN and include the followingpositions in theory and experiment: RSP Researchers, RSP Research Associates, and YoungResearchers, who are mentored by senior RBRC Scientists. A number of RIKEN Jr. ResearchAssociates and Visiting Scientists also contribute to the physics program at the Center.

RBRC has an active workshop program on strong interaction physics with each workshopfocused on a specific physics problem. In most cases all the talks are made available on the RBRCwebsite. In addition, highlights to each speaker's presentation are collected to form proceedingswhich can therefore be made available within a short time after the workshop. To date there areninety seven proceeding volumes available.

A 10 teraflops RBRC QCDOC computer funded by RIKEN, Japan, was unveiled at adedication ceremony at BNL on May 26, 2005. This supercomputer was designed and built byindividuals from Columbia University, IBM, BNL, RBRC, and the University of Edinburgh, withthe U.S. D.O.E. Office of Science providing infrastructure support at BNL. Physics results werereported at the RBRC QCDOC Symposium following the dedication. QCDSP, a 0.6 teraflopsparallel processor, dedicated to lattice QCD, was begun at the Center on February 19, 1998, wascompleted on August 28,1998, and was decommissioned in 2006. It was awarded the Gordon BellPrize for price performance in 1998.

N. P. Samios, DirectorMarch 2010

*Work performed under the auspices ofD.S.D.D.E. Contract No. DE-AC02-98CHI0886.

CONTENTS

Preface to the Series

Introduction .

First Measurement of W+/W- Boson Production at STAR in Polarized pp Collisions at RHICJan Balewski .

First Observations at PHENIX of W Production From Polarized pp Collisions at RHIC

David Kawall .

ResBos and RhicBos: QT Resummation for (un)polarized EW Boson Production

Pavel Nadolski .

Precision Determination ofMW from Observables at Hadron Colliders

Alessandro Vicini .

W and Z Physics from HERA

David South .

Measurement of W Boson Mass at DOJunjie Zhu .

Measurement of the W Boson Mass at CDF

Ashutosh Kotwal : .

Monte Carlo Modelling Issues for W MeasurementsJan Stark .

Theoretical Issues in Monte Carlo Modelling for W/Z Production

Jan Winter .

W Boson Physics and Global Analysis ofPDFs

C. -P. Yuan .

Prospects and Future of the STAR W ProgramCollisions at RHIC

Joe Seele .

Prospects of the Forward W Measurement in Polarized pp Collisions at the RHle-PHENIXExperiment

Yoshi Fukao , ..

ANofW Production in Polarized pp Collisions

Zhong-Bo Kang .

Precision Measurement of the W Mass and New Physics

Ulrich Baur ..

W Measurements and Prospects at ATLAS

Kevin Black .

Current Status and Prospects for W and Z Cross Section Measurementsat CMS

Carsten Magass .

The Status ofNNLO Tools for W/Z Production at Hadron CollidersFrank Petriello .

List of Registered Participants .

Agenda .

Additional RIKEN BNL Research Center Proceeding Volumes .

Contact Information

7

13

19

25

31

37

43

49

55

61

67

73

79

85

91

97

105107109

Introduction

A two-day workshop on "The Physics of Wand Z Bosons'' Was held at the RIKENBNL Research Center at Brookhaven National Laboratory on June 24-25, 2010.

With the recent release of the first measurement of W bosons in proton-protoncollisions at RHIC and the first observation of W events at the LHC, the workshopwas a timely opportunity to bring together experts from both the high energyparticle and nuclear physics communities to share their ideas and expertise on thephysics of Wand Z bosons, with the aim of fully exploring the potential of theW/Z physics programs at RHIC and the LHC.

The focus was on the production and measurement of W/Z bosons in bothpolarized and unpolarized proton-proton collisions, and the role of W/ Zproduction in probing the parton flavor and helicity structure of the collidingproton and in the search for new physics. There were lively discussions about thepotential and future prospects of W/Z programs at RHIC, Tevatron, and the LHC.

Organizers: S. Dawson, K. Okada, P. Patwa, J. Qiu and B. Surrow

First Measurement of W+/W- Boson Production at STAR in Polarized ppCollisions at RHIC

Jan Balewski (For the STAR Collaboration)Massachusetts Institute of Technology

balewski@mit.edu

The STAR experiment has acquired its first set of W -boson events from collisions of longitu­dinally polarized protons at VS = 500 GeV. The STAR Electromagnetic Calorimeter triggeredon electrons/positrons from the weak decay of the III and provided the energy of the lepton, whilethe STAR Time Projection Chamber allowed reconstruction of the lepton track and its chargesign. The QeD physics background was suppressed by isolation cuts around a candidate leptontrack as well as vetoing on transverse energy opposite in azimuth. In the standard model leading­order W± production is through u+d --+ W+ and d+u -+ W-. These interactions are ideal toolsto study the spin-flavor structure of the proton, because the spin-dependent W production crosssection ~a == a(pp) - a(*pp) depends strongly on the polarization of the quark and anti-quarkin the proton, with p(*P) representing a proton with its spin aligned with (against) its momen­tum. \Ve will present the status ofthe STAR measurement of AL = D..a j(a(pp) + a(pp)) formid-rapidity charge separated W+ and W-.

1

*AR Simulated W-+e+v event at STAR

_.......

v

--t

P

----7

P

--- ---

EM showerfrom W --> e(L2-trigger)

.- .-r:-ze

T~~ID CJ r~ rr . ~-'l fl r• r ['['-rJ~J ,~~_~,~-,J_ '_~,_,_J...L--=,_I_,I-~_='__~-.-J L, =J_-==:JL

tv

Ws@STAR,results and pe_rs:..:.p_e_ct_iv_e~s ~ _ ~__Ja_n_B_alewski, MIT I

*AR p+p~ W~e+v events selection

4x4 patchcentered on2x2 patch

0.5 _

-STAR data

M-C:W's

El M-C: QCD

M-C arb. norm.

E~/~4

3000

Zx2 EM cluster with highest ET sum,must contain tower pointed by the track

, , , t i , ,

Jan Balewski, MIT 2

0: I ~~:L.>C,.,.~2! I i,300,:200I

:100oI .DfI!IDS....~;"J...\,_..s >, , ..:•. ,).~ :.:.:.",..:.:.:.'t '

o - .---~--

4

6

o

2

8

Run 9 dataacceptedasWs

Ws @ STAR, results and perspectives

60, I

Transverseplane view

°0

:>Q) 50~--

I.Find lepton inTPC (direction) and in EMC (energy)-TPC & EMC matching .

2.Suppress QCD background-EMC cluster isolation-near jet veto-away ET veto

w

*AR j Reconstructed Jacobian Peak for W+, W- I

30 40 50 60 70EMC cluster ET (GeV)

2010

Run 9 STAR Preliminary~=500 GeVp+p -'J> w+ ~ e+ +V

positron !rll<1

- W+ candidates-+- Backg. est.

...... Backg. subtr. W+

01 'tf. - 41

20

60

40

80

23c~o()

Run 9 STAR Preliminary 'is = 500 GeVp+p~ w- ~ e- -s;

electron 1111 <1- W· candidates-+- Backg. est.

...- Backg. subtr. W·

01...... . , • !:T:7 • ' T , !• • • •

40

80

20

60

en....c~oo

~

Ws @ STAR. results and Jan Balewski, MIT 3

*AR t~~~~,~~~~~,~~~~~~i~~:~~~~~~~~~,1ll~- -+ c: + iJe H~+ -1- e+ + Ve

Run 9 STAR Preliminary p+p \jS=500 GeVKinematic acceptance: ~lel < 1 and E~ > 25 GeV

O'(W± -7 e± + vel

\• STAR Dala 0 C:::~~~.;~~I.

I Lumi. Uncert. -e- MR~~~~B,?e~um.

I ;:a~:~~:~. ~ CT~~~~~:sum.

51346 +36

-11O. so +0.12... 0 -0.09

13.7 ± :3.2

l;jG2G ~~l

() l":G +0.11.•J -0.09

1~3.7 ± ~3.2

Run 9 STAR Preliminary (p-p 500 GeV)

a w+ = 61 ± 3 (stat.) ~~~ (syst.) ± 14 (lumi.) pb

a w: = 17 ± 2 (stat.) ~~ (syst.) ± 4 (lumi.) pb

\.. rob.';J. 'tV

A'back

Etotal

.r Ldt (pb-1 )

w+I

'¢>

t:.~ ..., ...

I 'I II \

\,,If,,

I

, I

... '-;

80

30

40

b 90

:li'.s:

VI

OL--------------~

- ....... ..., ...

I \

20f;' It;\ I

10~, ;.... _...

t:. o(lo Ii w- There is reasonableagreement between themeasured and expectedcross sections.

We: (m !':TAR, results and perspectives Jan Balewski, MIT 4

*AR AL for Ws measured in Run 9

0"+ - 0"_

0"+ + 0"_

STAR Preliminary Run 9

A L

J~~~~~~~tm~~ ~

,.. -- .........._. -... -.F.:.:;.:,:;.-:w-

STAR Preliminary Rung \jS=500 GeV

p+p --) W± --) e± + v

e;>25GeV0.4

AL

0'1

0.2

0 ..... cr.AL=0'. + cr.

AL(W+) = -0.33 ± 0.10(stat.) ± O.04(syst.)

AL(W-) = 0.18 ± O.19(stat.) ~g:gj(syst.)

Jan Balewski, MIT 5

Summary(for mid rapidity leptons)

• Al(yV+) negative, as predicted, -3 sigma <0

• Al(yV-) central value positive, as expected

• systematic errors of AL under control

• TPC charge separation works up to ET-SO GeV21

W· W+ RHICBOS•••• -ONS-K.••• -DNS-KKP.... -OSSV08del'lorian & Vogelsang...• -.- DSSV08

I"'. ~ ' Syst. uncertainty due to abs.

i polariZatic;>" and background

...-..-_ .......... --.

I _ .

-0.4

-2 -1 0

I lepton 11

~ STAR. results and perspectives._---------~-----------

-......J

First Observations at PHENIX of VV Production from Polarized pp Collisions at RHIC

Dave Kawall, RIKEN-BNL Research Center and University of Massachusetts Amherst

on behalf of the PHENIX Collaboration

•~t

/!

/1

ct

The evidence for pp ~ Ht + X --+ e + X' in polarized pp collisions at VB == 500 GeV inthe PHENIX detector at RHIC is presented. The physics importance, analysis strategy, andpreliminary results on the single longitudinal, parity-violating spin asymmetry Arr

+ are also

presented.

D. Kawall TV and Z Workshop, BNL. June 2-1-25 2010

Motivation for Spin Physics with Vlls at RHIC

® Key measurement of spin program: flavor separated, polarized PDFs 6D,(x) and 6rl(~r)

$ Semi-inclusive polarized DIS experiments (SMC, HERMES, COMPASS) have made such measurements

@ STAR and PHENIX can do it exploiting maximal-parity violation in W production in polarized pp collisions

Measurements made at high scale O\1a/ > 6000 GeV2 )

No uncertainty from fragmentation (couplings of VV well known)I no higher twist effects

0.04-

xAu xi\d _.. 0.04

@l Unpol. PDFs known to about 10~;Q

@l Theoretical uncertainties small(NLO+resummation)

• Robust extraction of 6u(x) and t6.d(x)

f) Can also measure ratio u(x)jd(x)

-<= D. de Florian, R. Sassot, M. Stratmann,and W. Vogelsang, Phys. Rev. Lett.101, 072001 (2008)( At Q2 = 10 GeV2 )

0.3

o

o

0.1

0"

0.02

-0.1

-0.02

-0.04

xAs

o J.- - - - -.,.~;,.; :.,~

o f- ··· - ·- ·•··..·.·.f

0.02

0.04

0.02

-0.02

-0.04

-0.02

-0.041-- Q2::= 10 GeV2

00

10 -... -I10 x 10-2 -j

ro x

D. Kawall TF and Z Workshop, BNL. June 24-25 2010

PHENIX Central Arm Spectrometers

\.Q

West

PHENIX Detector

Beam Vie".' East

• Electromagnetic calorimeter (EMCal

fi nely segmented :

6.¢ x 6.r, ~ 0.01 x 0.01

• Calibrated with M:», of 1r0 at high P7

PbGI

1'-0~ l s;¢'J.. ~ 1 1 18~~~~06~~.Fooooo~oOTOOO

6 8 to 12 1. 18 ''tilpt (GeVlc)

Focus on jJp ~ lV± + X ~ e± + X'

• Detect high E e± in central arms of PHENIX

4ft Acceptance of each arm: rapidity /17j < 0.35(70 < e < 110), 6.¢==1r/2

e Vertex cut: Izl < 30 cm

~ Tracking: Charged tracks measured iDrift Chamber (DC) and Pad Charr

ber(PCl)

* J13 .dl ==- 0.78 Tesla-meters

D. Kawall rv and Z Workshop. BNL June 24-25 2010

Comparison of Data with Background Estimation

70PJGevfcl

""'~'"

PH· EN'Xe10·20GeV 8esumedto be all 80)

At"'.....DY1"'i4IA CnormlliHdl

+ Raw counts (Negative C(.EMC81 cfuster aHociamd with ttack)

BO.timation

is

o .....,"'~ •

PH ENIXEi'

Raw counts (Positive Charge){EYeal cluster associated with track}

~ Data driven BG estimation(10..20GeV assumed to be ai' BG)

i~ iii ~"BG+PYTHIA(normalized)

I8

~

o

To determine background under signal region (30-50 GeV) :

• Take measured nO + r spectrum x conversion prob + accidental matching track ® ac-ceptance

~ Add charged hadrons (NLO) 0 detector response (GEANT) + e± from FONLL c/b decays

~ Normalize h± component so total background matches data in range 10-20 GeV

8 Black histogram: background estimate; largest component from 11"0 + r, h± slightly less

D, Kawall n' and Z Vv'orkshop, BNL, June 24-25 2010

Parity-Violating Single Spin Asymmetry ",4L (tfp ---+ "VV+ -4 e")

~ Preliminary result, using PE = 0.38 ± 0.04 and Pv = 0.40 ± 0.04 (SP/P = 9.2S~)

e Raw asymmetry in background region (12-20 GeVIc) consistent with 0 : E~~~d = 0.035 ± 0.047

~ Raw asymmetry in signal region (30-50 GeV/c) inconsistent with 0 : E;~~?al = -0.29 ± 0.11

e A L = ~ X Eraw X D, correct for dilution of A L by Z and QeD background (D = 1.11 ± 0.04)r-~cc~--_cc~c_---~~-~c_~'~_C_-' .~.~ ..~

I AL(jJp -+ W+ -+ e+) = - 0.83 ± 0.31

--..J

« 0

AL w+ ~ e+ (ly~J<O.35)=::;:~ f--- - ~~~~~i~~I)f _-DHS,mftl

-O$SV-GRSVv,al

PT

[GeV/c]

• 30-50GeV/c rang<P>=O.39±O.04

dilution 1.11±O.O

A~'0 30 35

PH.i'I:'ENIX

-0.6

.O.2~. t ' I .. I: :=

..0.8

..OA

D. Kawall TF and Z Workshop, BNL, June 24-25 2010

.......tv

Summary and Outlook

@ Developed analysis techniques to isolate lV ---+ e signal above backgrounds

• Clear evidence for W"± ---+ e± at 1171 < 0.35 in PHENIX central arms

• Preliminary determination of single-spin parity-violating asymmetry:Arl(pp ~ lV+ ---+ e! ) == - 0.83 ± 0.31

$ Analysis underway for cross-section estimates, final Ar7± determinations

e Upgrades will help refine analysis, add acceptance and new physics channels:

Si Barrel vertex detectors in PHENIX central arms

Muon arms: RPCs + muon trigger upgrade: W ---+ f.-l signal 1.2 < l17ftl < 2.2

• (-AD getting closer to design luminosity at yI506 GeV, ~ 40% polarization

e Will need 300+ pb-1 integrated luminosity, 60% polarization to meet goals of program

D. Kawall TV and Z Workshop, BNL June 24-25 2010

I--'

W

ResBos and RhicBosQT resummation for (un)polarized EW boson production

Pavel Nadolsky

Southern Methodist University

June 24, 2010

Pavel Nadolsky (SMU) W/Z workshop, BNL 06/24/10 1

~

+:>.

Objectives of the talk

An overview of physics in

• ResBos: Resummation for electroweak Bosons and theirdecays in unpolarized pp or pp collisions

• RhicBos = ResBos adapted to compute longitudinalsingle-spin and double-spin asymmetries in leptonic decaysof r*, ~ Z in pp collisions

• Single-spin asymmetries in hadronic decays of W· bosons -0

useful measurement complementary to the leptonic mode

. Interruptions and questions are welcome'

Pavel Nddolsky (SMU) W/Zworkshop,BNL 06/24/10 2

Today's focus is on...

.-Vi

• unpolarized partondistributions:

• longitudinally polarizedparton distributions:

• unpolarized cross sections:

• single-spin cross sections<#- 0 if V - A interaction):

• single-spin asymmetry asa function of W boson rapidity

y:

fajp(x, Q) - f:/p+(x, Q) + f:;~+(x, Q)

llfajp(x, Q) f:/p+(x, Q) - <:Ur, Q)

(J = ~ [(J(P->p) + (J(P+-p)]

f:,. L (J = ~ [(J (p->p) - (J(p+-P)]

dllLajdyAL(y) - d(Jjdy

Pavel Nadolsky(SMU)W/ZWorkshop, BNL 06/24/10 3

Two classes of subprocesses with W bosons

-,

'\-dd

1J,~ w+ <e+-~d l/e

11·

1: Resonant (s-channel) W boson production

• dominant parity-violating processat Q ~ AIHl

II Leptonic decays: Br(W ~ eVe) ~ 10.8% ­RhicBos

• Hadronic decays: Br(W ~ hadrons) ~ 67%I--"

0"1

d I etc.

9

d d

,*,Z

dd

Hl

u 11

w

d

2: Non-resonant scattering into a dijet final state,mediated by -r, W, Z, and g, and interference termsu. . d u I U U I • U U U

Pavel Nadolsky (SMU) 'W/Z workshop, BNL 06/24/10 4

.......-...J

Related publicationsOn-shell W boson production

1. C. Bourrelv. J. Softer. PLB 314/132 (1993); Nucl.Phys. B423, 329 (1994). 2. A. Weberf Nucl. Phys. B 403/ 545 (1993)3. RNcdolskv. hep-ph/95034194. T. Gehrmann, Nucl. Phys. 8534,21(1998)5.. M. Gluck, A. Hartl, and E. Reya, Eur. Phys. J. C19, 77 (2001)

Leptonic decay mode1. B. Kamal, Phys. Rev. D57/6663 (1998)

2. F? Nadolsky and C.-F? Yuan, NucL Phys. 8666,3 and 31 (2003)

Dijet mode1. H. Haber and G. Kane, Nucl. Phys. B146,109 (1978)2. F. Paige, T. L. Trueman, T. Iudron. Phys. Rev. D 19,935 (1979)3. C. Bourrely, J. RGuillet, and J. Soffer, Nucl. Phys. B361, 72 (1991)4. S. Arnold, A. Metz, V. Vogelsang, arXiv:0807,3688; S. Arnold,

K. Goeke, A. Metz. RSchweitzer, W, Vogelsang, Eur.Phys.J.ST 162(2008)

Pavel Nodolsky (SMU) W/ZworkshopjBNL 06/24/10 5

-00

Data-driven search for resonant VV ~ jet + jet contributions

AL(y) is most accessible in the signal region:

Q == M~v ± 10 - 15 GeV, PTj 2: 25 GeV, IYIj - Y2j! ;S 1

The measurement can be based. on the following strategy:

1. Discard events with gluon-Iike jets (wide. large multiplicity) tothe best of ones ability

2. Precisely measure the smooth backgroundoutside of the signal region

3. Use this measurement to predict and subtract thebackground inside the signal region

4. Look for a large .44L (y) at y > +1(driven by a large ilu(x)j'u(x) ot » ~ 1)

5. Measure moderate AL(y) at y < -1to constrain fj.d(x ) / d(x) at x < 0.1

Pavel Nadolsky (SMU) W/Z workshop, BNL 06/24/10 3"]

Precision determination of MWfrom observables at hadron colliders

Alessandro ViciniDipartimento di Fisica, Universita degli Studi di Milano and INFN, Sezione di Milano,

Via Celoria 16, 20133 Milano (Italy)

Abstract

The measurement of ~1W will probably reach the 15 MeV level at the Tevatron. Themeasurement of this pseudo-observable heavily involves theoretical ingredients. In orderto attempt an estimate of the final theoretical systematic uncertainty, one needs a classi­fication of the impact of different classes of radiative corrections in terms of shifts of thefinal value of M\V.

Once known higher order effects have been estimated and possibly included in the dataanalysis, it will be possible, by comparing the predictions of different codes, to study theremaining sources of theoretical uncertainty and to obtain a final theoretical systematicerror on 1''''1\\1.

Fixed order calculations provide the first basic estimates of the relevant cross sections,but a realistic simulation shows which effects survive after e.g. the convolution withmultiple gluou/photon emission and with the smearing of lepton momenta. or the lepton­photon recombination.

In this talk I will describe a simple procedure to perform a template fit of theoreticaldistributions, treated as pseudo-data, deriving a classification of the impact of M\V ofdifferent classes of radiative corrections. This procedure will be applied to study: i) changeof E\iV input scheme, use of factorized expressions, E\V higher orders; ii) QeD correctionsby different codes; iii) combination of QCD+E\V corrections; iv) PDF uncertainties.

19

The template fitting procedureA distribution computed with a given set of radiative corrections and with a given

value M\Vo is treated as a set of pseudo-data. The templates are prepared in Bornapproximation, using 100 values of MWi Each template is compared to the pseudo-dataand a distance is measured.

Nbins

X2

= ""'1. Z::j=l

( Ojata _ o~empl=i) 2

(a1ata) 2i = 1~ ... , IVtempl (1)

The template that minimizes the distance is considered as the preferred one and thevalue of I'vlW, used to generate it, is the measured M\~T.

The difference I'v1W-MWo represents the shift induced on the measurement of the VVmass by including that specific set of radiative corrections

The distributions used in the evaluation of XT in general do not have the same nor­malization. It is also possible to compare distributions that have been normalized to theirrespective cross-sections, to appreciate the role of the shape differences.

2.5

2

1.5'"

..............

................" ................ ..... ~.~~ -,

nominal MVil=80.398 GeVTevatronpp-? H!± -? fW,.

1M10M

100 M340 M

templates with 1B events

0.5 +------..----,.-----.......--,---,----"---..,----j

80.38 80.385 80.39 80.395 80.4 80.405 80.41 80.415 80.42

Alvl/ (GeV)

Figure 1: Pseudodata in Born approximation, fitted with Born templates. The nominalM\iV value used to generated the pseudodata is found from the fitting procedure, withincreasing accuracy depending on the number of events in the pseudodata sample. The~X2 = 1 rule, valid in this exercise, determines the uncertainty in the fitting procedureassociated to the extraction of a preferred value of M\\1.

20

Effect of higher order corrections in the 0:(0) input scheme

nominal MW=80.398 GeVbare cutsTevatronpp -+ W+ -+ f.l+1JJ.!

1.4

1.2

0.8

0.6

0.4

0.2

o80.3

i&f0) O(a) FSR-PS!f ~(O) exp FSR-PSi! !a(O) exact O(a)!i J a(O) bestif ifitiff!f I:;I:: iif!if J

:= f:Ifif I:: f

\.J)80.304 80.308 80.312 80.316 80.32 80.324 80.328

1Y1w (GeV)

Figure 2: Impact of different higher order corrections, all evaluated in the 0:(0) inputscheme, on the extraction of a preferred MW value.

The templates used to evaluate the effects in fig.2 have been prepared using HORACE,Born approximation, a(O) input scheme, 10 billions of events, 80.248 :s: ~,",,1lV :s: 80.348GeV.

21

Effect of different EW input scheme choices

1.4

1.2

0.8

0.6

0.4

0.2

o80.3

acp scheme I0:(0) 0(0:)

(XcI' scheme IIcxc" expcx(O) exp

nominal M\V=80.398 GeVbare cutsTevatronpp ---+ vV+ ---+ M+Vt-t

80.304 80.308 80.312 80.31G 80.32 80.324 80.328

Mw (GeV)

Figure 3: Impact of different E\V input scheme choices on the extraction of a preferredMW value, in different perturbative approximations.

The templates used to evaluate the effects in fig.3 have been prepared using HORACE,Born approximation, 0(0) input scheme, 10 billions of events, 80.248 ::; 2\1~'V ::; 80.348GeV.

22

Effect of different methods to include multiple gluon radiation

30 ,-------,.--.......,---..,.------r---,

25

2Q

60 70

mlf (GoV)

so 100

Figure 4: Transverse mass distribution obtained with different code that share NLO-QCDaccuracy but include multiple gluon radiation with different approaches: analytical re­summation (Resbos) or QeD Parton Shower with different ordering algorithms (HER\VIGvs PYTHIA)

3"POWllEG+HERlIf&POllHEG+P'ffHIl\"

30 Re sbee-v-r-'NLO-QG!;--

25

€'J

i~

15

10

02[, :10 3fJ 40 4fl 50 ss,

(GoV)~

Figure 5: Same as in fig.4, for the transverse lepton distribution.

The templates used to evaluate the effects in fig.4,5 have been prepared using Resbos,best approximation, 0:(0) input scheme, 1 billion of events, 80.348 S lHTV S 80.448 GeV.

The effect of the corrections is very stable in the case of the transverse mass distribution(.6.MlV = +18 MeV) for both PO\VHEG+HERWOG and PO\VHEG+PYTHIA. In thecase of the lepton transverse momentum distribution, the fitting procedure is much moresensitive to the QeD details of the different approximations) both for their impact on thenormalization and on the shape of the distribution.

23

Effect of the combination of EvV and QeD corrections

The QeD and E\V corrections to different distributions can be combined, up to terms of0(0:0:8 ) and of terms of O(CY~), according to the following recipes.

(2)

(1 + [rc,]MC@NL~- [rc,]HERWIG PS) x {[~~] } ... (3)

[dO LOIN LO EW BERM IG PS

80.480.38

! additive

/ factorized

/,/

"

80.34 80.36

1'v1w (GeV)

80.32

o80.3

1.2

1.4

'"C'-l'g 0.8;><I

C'l

0.6;><

0.4

0.2

Figure 6: Preferred M\V value obtained in the two approximations of eq.2 and of eq.3

The templates used to evaluate the effects in fig.6 have been prepared using Resbos,best approximation, 0;(0) input scheme, 1 billion of events, 80.219 ~ AHV ::; 80.419 GeV.

24

.' technische universitatdortmund

tvlJ)

Wand ZPhysics from HERA

David South (Technische Universitat Dortmund)on behalf of the Hi and ZEUS Collaborations

The Physics of Wand Z Bosons June 24 - 25 2010 BROOKHAVEN/ / NATIONAL LABORATORY

Outline:Introduction to HERA, Hi and ZEUS·High Q2 Measurements of Neutral and Charge CurrentCombined Hi and ZEUS measurements and QCDjEW fitsRare processes at HERA involving Wand Z BosonsSummary

Efectroweak Physics at HERAInclusive measurementselectroweak effects at Q2~Mw,z

HERA

QeD and electroweak fits to the HERA data

H1 preliminary vu -v.....-PlW(preil

t. v" -POF(Prell

* Standard Model

-1 ~ -" LEPEWWG

COF

-1 -0.5 0 0.5au

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-0.5

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>

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~::::-., p+ e+q • -W'" - -

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C ZEUS .'p He 0&07 (prellQ ZEUS .'p NC 05-0&

- SM .'p He (HERAPOF , ,0)~ SM e~p Nc (HERAPDF 1.0)

..­:>Q)

e 10:i3a

N0-.

Measurements with Wand Z bosons at HERA are within reach!

DavidSouth, W/Z Physics from HERA, The Physics of W/Z Bosons, BNL, June 24-252010 ~ ;~~~I~.li~~~e IJnj'\'Br$iti5~

HERA II Polarisation Asymmetry in NC

1ir------------·

• A e'p0.51- - H1PDF 2009

A± = 2~. _()~c(~)-a~c(~)

.~ --Pr a~c(l1)+al~c(Pr)

PR >0

PL <0

NR-NL

NR+NLp-

e

-«a:wI

t ~ t 1-----1

-------+~ influence of ZOH1 Preliminary

• A ep

- H1PDF2009

y

-0.5

A

N-......)

104

Q2 [GeV2]103

-I ' 1 i ! I 'i! i '

Form polarisation asymmetry from HERA II Neutral Current measurements

- clear observation of parity violation of NC electroweak exchange

Nicely illustrates the properties of the different polarisation and lepton charge data

Well described by the SM prediction

David South, W/Z Physics from HERA, The Physics of W/Z Bosons, BNL, June 24-25 2010 ~ ~~;~~I!,~~~e Ulll\",~rSlt~t

Charged Current Cross Section vs. Polarisation

e+p~yX

• H1 HERA Io H1 HERA II (prel.)f::,. ZEUS 06·07 (prel.)A ZEUS HERA I

e'p ~vX• H1 HERA Io H1 HERA II (prel.)... ZEUS 98·06

o

Q2 > 400 GeV 2

y<0.9

·0.5

- HERAPDF 1.0

0.1

HERA Charged Current e'p Scattering

40

80

20

60

.... 120, iii iii iii iii j iii iii

.cCo-se 100

Data exhibit linear dependence of average polarisation andHERA I and II measurements agree with the SM prediction

Measurementsmade by ZEUSusing various

polarisation values

• ZEUS CC e-p (175 pb-1)

o ZEUS CC (P =0) e-p (16.4 pb' ')- SM (ZEU8-J"ETS)... -. 8M (CTEQ6D)

8M (MRST04)

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N00

DavidSouth, WjZ Physics from HERA, The Physics of W/Z Bosons, BNL, June 24~2S 2010.t1'!'T!\ technische uni-,,'8"lsitat~ dortmund

Impact of HERA Data at the LHCW+, Z rapidities (at 14 TeV!) after Voica Radescu, andAmanda Cooper-Ssrkar

Prior to any HERA data Only ZEUS data Separate HI and ZEUS HERAPDF 1.0

2~- 2( 2 r.~i~:--~--:~~"j ~ !iC~~';C~='::"::-":~~'~'i" j L5.

1v~=-'~\ ;'.:

, . D.5 \0.5

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Experimental uncertainty at central rapidities using combined HERA data-1%1http://www.desy.de/hlzeus/combined_results/benchmark/herapdfl.O.html

IIA

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v

8.4 r----.. -..-.- ----, 0.4 ---~-~,- -1'o.J L "" ~~_. OJl .. -_" ""." .

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\ Note scale!

tv\D

Impressive precision on the low x sea and gluon of the HERAPDF 1.0 is relevant forW,lproduction at the LHC

Inclusion of HERA data shows the tremendous improvement on the predictions for Wand lproduction at the central rapidity

DavidSouth, W/Z Physics from HERA, The Physics of W/Z Bosons, BNL, June 24-25 2010 ~ ~";~;;;~~~eo,,,v8rs,""

Hl+ZEUS Isolated Leptons: Results

• H1+ZEUS (0.98 fb")SM

E2J SM Signal

J!Je 50~W

40

30

20

10

• H1.j.ZEUS(0.98 lb")_SM[22J SMSignal

Jacobian...-- peak

J!JcQ)

Iii 102

• H1.j.ZEUS(0.98 lb")_8MEZJ SM Signal

V.Jo Hl+ZEUS Data SM SM OtherSM

1994-2007 e±p 0.98 fb- 1 Expectation Signal Processes

Electron Total 61 69.2 ± 8.2 48.3 ± 7.4 20.9 ± 3.2

pI> 25GeV 16 13.0 ± 1.7 10.0 ± 1.6 3.1 ± 0.7

Muon Total 20 18.6 ± 2.7 16.4 ± 2.6 2.2 ± 0.5

pI> 25GeV 13 11.0 ± 1.6 9.8 ± 1.6 1.2 ± 0.3

Combined Total 81 87.8 ± 11.0 64.7 ± 9.9 23.1 ± 3.3

Pi > 25 GeV 29 24.0 ± 3.2 19.7 ± 3.1 4.3 ± 0.8

Good overallagreementwith theStandard Model

SM expectationdominated Wproduction~ Cross section

Measured: 1.06 ±O.16 (stat.) ± 0.07 (sys.) pb SM: 1.26 ± 0.19 pb from EPVEC NLODavidSouth, WjZ Physics from HERA, The Physics of WjZ Bosons, BNL, June 24-25 2010 @:. tu ~~';";~:~~~ecni""'"itat

DfJ~...'b''''ii'''*'ATA.

I

Measurement of W boson mass at D0

w....... Junjie Zhu

University of Michigan

The Physics of Wand Z Bosons

June 24, 2010

...~-XiiiUA.'§-...... ~ W boson mass

ita 1 1M 2- _

TY - JiGF

sin ' Ow (1-Q2») t:l r - 30/0

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-, ;:;, /"'-~

Mw can be increased by up to 250 MeV in MSSM

A precise measurement of Mw can be used to makeindirect constraints on MH and possible new physics

2010-06-24 Junjie Zhu

I

ww

~..'hii.'ifiiil'.... ~

W~ev

Measurement strategy

Z~ee

.,

• Three observables: PT(e),PT(v) (inferred from missing transverseenergy), transverse mass MT2=(ETe+ETv)2_1 P;e+PTv 12

• Develop a parameterized Me simulation with parametersdetermined from the collider data (mainly Z~ee events)

• Generate Me templates with different input Mw, compare with datadistributions and extract Mw

• Z ~ee events are used to set the absolute electron energy scale, sowe are effectively measuring Mw/Mz2010-06-24 Junjie Zhu

......-t.'.:iii,,§1.T.~

Calibration results .,

I 0.4 < 1111 < 0.8 (R:o.7) J

0.4< If) 1<0.8

70

zmass .. 90.958 ± 0.032 GeV

L resn « 2.095 ±O.038 GeV

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I Z--.ee I

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,j* , 'ttl. re:e::::c d • d • J. • ... h J ~.t

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2010~06~24 Junjie Zhu

Before...--~-i--:

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.. i.

wVl

M z = 91.185 ± 0.033 (stat)GeV M w = 80.401 ± 0.023 (stat) GeV

(WA M z=91.188 ± 0.002 GeV)

PRL 103, 141801 (2009)

2010-06-24 Junjie Zhu

Uncertainties....,

.'·'II:+I..'§I...... ~......-...

w0\

a(Tnltv) l'v'1eV~

Source TnT PT ItT

Electron energy calibration I:34 :34 34Electron resolution model 2 2 3Electron energy offset 4 6 7Electron energy loss model 4 4 4Recoil model 16 12 20 IElectron efficiencies 5 6 5Backgrounds 2 5 4'ExperiInelltal Subtotal :35 :37 41

P~F 19 11 14 fQED 7 7 9Boson ]JT 2 5 2 .Productioll Stlbtotal 12 14 17'Total Systclnatic :37,1 0 44Statistical 2:3 27 23Total 44 48 50

2010-06-24 Junjie Zhu

w-.)

Measurement of the W Boson Mass at CDFAshutosh KotwalDuke University

We present a techniques used for precise measurements of the W bosonmass at the CDF experiment at Fermilab. We present the results and theprospects for future improvements at Fermilab and the LHC.

Riken Brookhaven Research Center WorkshopJune 24-25,2010

w00

Outline of CDF AnalysisEnergy scale measurements drive the W mass measurement

• Tracker Calibration

- alignment of the central drift chamber (COT with ~2400 cells) usingcosrmc rays

- COT momentum scale and tracker non-linearity constrained usingJ/lIJ -----. J.l J.l and Y ------'J.l fJ mass fits

• Confirmed using Z -~ J.l J.l mass fit

• EM Calorimeter Calibration

- COT momentum scale transferred to EM calorimeter using a fit to the peakof the E/p spectrum, around E/p ~ 1

- Calorimeter energy scale confirmed using Z -.ee mass fit

• Tracker and EM Calorimeter resolutions

• Hadronic recoil modelling

- Characterized using PT-balance in Z ----....11 events

Internal Alignment of COT

• Use a clean sample of~200kcosmic rays for cell-by-cell internalalignment

VJ\0

• Fit COT hits on bothsides simultaneouslyto a single helix(A.Kotwal, H. Gerberichand C. Hays, NIMA 506,110 (2003))

- Time of incidence is afloated parameter

• Same technique beingused on ATLAS andeMS

+:>.o

~p/p

..0.001

-0.002

Tracking Momentum Calibration

• Set using JI'V -.. JJIJ and Y-.. JJJJ resonances- Consistent within total uncertainties

• Use II'V to study and calibrate non-linear response of tracker

• Systematics-dominated, improved detector modelling required

I-1 COF II JL dt~ 200pb·

1

CDF II L dt z 200 pb

Scale correction =(-1.64±O.01start0.06slope)x10-3

JI'¥ mass independent OfPT(IJ)

~ * •. .•-t-- ·

-0.0030

J/lP~~l~ data

<l/p~t~» (GeV'f)q.1

<1/P!;> (GeV' )

0119

y -~ JJ ~ mass fitI

9.5I

10m~~ (GeV)

z~ll Mass Cross-checks

• Z boson mass fits consistent with tracking and E/p-based calibrations

CDF II L r-J 200/pb+:-.I--'"

~o

M(~~) (GeV)

110m~l!1 (GeV)

~Datal .Simu ation

l/dof = 32 I 30

Mz =(91184 ± 43) MeV

400

M(ee) (GeV)

t~1 .-:. D.ataM

z=(91190 ± 67 ) MeV rrrrr~ SImulation

stat ~ I

x'/dof =34 I 38 r t~~t ~r 11

.i, + +t~l ~\._A-*~.#t! I. _.1

80 - ,-

200

>(1)

U 100If)

o---­CZl~

~(1)

>l:Ll

"t:;;.tv

Summary

• The Wboson mass is a very interesting parameter to measure with. . . .mcreasmg precision

• CDP Run 2 W mass result with 200 pb' data:

- Mw == 80413 ± 48 MeV

• DO Run 2 W mass result with 1 fb' data:

- Mw == 80401 ± 43 MeV

• Most systematics limited by statistics of control samples

- CDP and DO are both working on c>Mw < .25 MeV measurements

from ~ 2 fb' (CDF) and ~ 4 fb' (DO)

• Learning as we go: Tevatron~ LHC may produce bMw r-.I 5-10 MeV

Monte Carlo modelling issuesfor W measurements

Jan StarkLaboratoire de Physique Subatomique et de Cosmcloqle

Grenoble, France

~w

The physics of Wand Z bosonsRIKEN BNL Research Centre Workshop, June 24-25,2010

IN2P3Les deux infinis

crprs<l.)

""~, C.

"<1>"C

--------~~--~~

~1~:c;;:-; ~ _!=J__~b L ~----------Laboratoire de PhysiqueSubatomique et de Cosmologie

ContextMost of the comments in this talk are based on experience from the 00 1 tb' measurementof the W boson mass. A complete overview of this analysis was described in Junjie Zhu's talkearlier today. Here we provide more details on the use of simulations in this measurement.

CDF Run 011 • 80.436 ± 0.081

DO Run I --+--t 80.4781:0.083

CDF Run II -.-.... 80.4131:0.048

Tevatron 2007 ....-.-. 80.432 ± 0.039

DO Run II ~ 80.402 ± 0.043

Tevatron 2009 ......... 80.420 ± 0.031

LEP2 OV~;-r\)gl~ "'-1f?-~ 80.376 :: 0,033

World average ..... 80.3991: 0.023

I I I JvfyGl>

80 80.2 80.4 80.6(GeV)

···'lnr-.<'j~

-DATA-FASTMC.w·~,,,

!i@lilz->coOCD

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> ~aooof~ ::00 --,"? 7600·:'"c!li 5000

~

+::­+::-

But many of the techniques and strategies discussedhere also apply to many other Wand Z measurements ...

1.5 ;: 2.5

11]"'

CTEQ6.f. Ulll,'erl:dnt)' rt"ud

The physics of Wand Z bosons, Brookhaven, June 24-25, 2010

00. L=O.75fli'

~25GcV

Er>25 GcV

-("TEQ6.6("t'ltlrnlml-ue

"---' "Ut:-iT!.MNJ.OI.'t'IlITlllmlm·

.--... 0.2

:5~- .....,.-.. ..00 ~ -0.2

~N ~

-7' -004

e~

-J -0.6

0::: 0 0.50...

Jan Stark

~Vl

Reminder: signature in the detector,requirements on precision

Isolated, high PT leptons,missing transverse momentum in W's

Z events provide criticalcontrol sample

Of .~

L

In a nutshell, measure two objects in the detector:- Lepton (in principle e or J1; e in our analysis),

need energy measurement with 0.2 per-mil precision (11)- Hadronic recoil, need - 1% precision !

_._--~-

Jan Stark The physics of Wand Z bosons, Brookhaven, June 24-25, 2010

Measurement strategy

Validated inliMe closure test"

v

+Parameterised detector model

l ~i ,

W mass templates

+- calorimeter energy scale backgrounds

data____ -:binned likelihood fit

- recoil

W mass is extracted from transverse mass, transverse momentum andtransverse missing momentum:Need Monte Carlo simulation to predict shapes of these observables forgiven mass hypothesis

NLO event generator: 00 uses ResBos [Balazs, Yuan; Phys ReV056, 5558] + Photos {Barbiero, Was; Comp Phys Com 79, 291] forW/Z production and decay

Detector calibration

q

ii'

+:>.0'\

!Wmass

Jan Stark The physics of Wand Z bosons, Brookhaven, June 24-25, 2010

~......:J

"First principles" vs. "parameterised"simulations

We all like "first principles" simulations, i.e. simulations where everything is based ona formal theory that predicts everything.

Examples: - A gauge theory used to simulate some e+ e --+ X collision.

- A simulation based on the known laws of the interactions betweenhigh-energy particles and matter, as well as a model of the 00 detectorgeometry is used to predict the electron energy response in 00.

But what to do when the "first principles" cannot be made precise/complete enough?

Examples: - Tricky mathematical issues in QeD description of p' p+/- --+ X .

- Response to hadrons not simulated quite right in detector simulation.

Here "parameterised" simulations can be very powerful, because they have simple "knobs"that we can turn to adjust things.

Examples: - Non-perturbative form factors to be determined from collider data.- Simple parameterisation of hadron energy response, to be fit to control

sample from collider data.

In practice, the trick is to combine the two approaches. In the 00 m(W) measurementwe have a parameterised simulation with many parameterisations derived from first-principles simulations.

Jan Stark The physics ofW and Z bosons, Brookhaven, June 24-25, 2010

Model of W production and decayTool IProcess QeD E\~,7

RESBOS

\VGRAD

ZGRAD

PHOTOS

w.zBi­

Z

NLOLOLO

complete 0(0), Matrix Element. ~ 1 photoncomplete O(Q): Matrix EleulCut: ::; 1 photonQED FSR; < 2 photons

.,J:::..00

Our main generator is "ResBos+Photos". The NLO QeD in ResBos allows us to geta reasonable description of the PT of the vector bosons. The two leading EWK effects

are the first FSR photon and the second FSR photon. Photos gives us a reasonablemodel for both.

We use W/ZGRAD to get a feeling for the effect of thefull EWK corrections.The final "QED" uncertainty we quote is 7/7/9 MeV (mT,PT,MET).

This is the sum of different effects; the two main ones are:

- Effect of full EWK corrections, from comparison of W/ZGRADin "FSR only" and in "full EWK" modes (5/5/5 MeV).

- Very simple estimate of "quality of FSR model", from comparisonof W/ZGRAD in FSR-only mode vs Photos (5/5/5 MeV).

Jan Stark The physics of Wand Z bosons, Brookhaven, June 24-25, 2010

..(:::..'-D

~~%:,."·",:·,,..,,:);B:,~S::,:,*:;~i;~<®~~:W,m~~~~3rn~~~~:~~:",:,,:,:,:::::::·::..:~::/'~~),<;~mm':~TI:m:::t:f::,:,:'<;::r:~~~~~;:~:F::~~m~:i::8~~~~~~:~"087f8''f:~'f~~7~:\::):,:::~::)::::)::}*~~~~:,'; "'·'Ff:,:~~:,,~:.,i'dii. ,,20"; ~::::b:::~:iMt;::>t' b:.:- hA{<.::1i!>.Li;:i;,A6:~:::~%, M,:)1R" 4:.:,:" ,,·,,4';',,$ .'" @..:),,%£4h,:.:,:,:.¥d.,,% ,', {~,~:.;::::::",:i;: g;;:;.;:;:

Theoretical issues in Monte Carlo modellingfor WIZ production

[ Physics of Wand Z bosons - workshop @ RIKEN BNL research center]

Jan Winter a

- Fermilab-

I give an overview of how vector boson production isprocessed in Monte Carlo event generators. In a high­energy hadron collider environment this is always affected by QeD radia­tion. Parton showers can capture the leading effects of soft and collinearemissions, but fail to sufficiently describe hard jets associated with thevector boson. One therefore has to improve parton-shower approaches to

gain a good understanding of V+n jets - a major background to all newphysics searches. I briefly review tree-level matrix-element plus parton­shower merging and NLO calculations as means to predict V+n jet pro­

duction. I compare both types of calculations and discuss their results.

a Sherpa authors: J. Archibald, T. Gleisberg, S. Hache, H. Hoeth, F. Krauss, M. Schonherr, F. Siegert,

S. Schumann, J. Winter and K. Zapp http://www.sherpa-mc.de/Jan Winter BNL. June 24, 2010 - p.1

'Mf 4'T"1!t"m"t"trt'wrw"mrw=rzrr~; ,..:

Monte Carlo modelling of a (high-PT) event

:> Factorization approach: divide jet simulation into different phases

.. Perturbative Phases: [parton jets}

Hard process/interaction (hard jet production)exact matrix elements IM/ 2

QeD bremsstrahlung (soft/coli multiple emissions)initial- and final-state parton showering

Multiple/Secondary interactionsmodelling the underlying event

~

..,

..T--.

'"' .... Ie -- •--\ \.\ Tf'!',.I·o~r "''ft-•• ',: t~ Fi./ ,•• ~~

__ "\! ••~ ,Ill. It. 'I 1--. e::.'\, .0 ~~. --~~' 1,/ I, / /,/7 •.. \\ .. e\ _.;.;. "/ ./,~\ III ~\~. \"-b ~~• .:.,

••,.' ., .\ .....') bAO '" v/·.... ",--.~-"••:-:~, ~ :...-.;p ~ Ii;;"' .;> "'~, jj:.-~~--...---

-- tft~~'~ ~!ft:[ ~~ !j~~~ \"~~--

~~.~:;! ;;~::\,~ ~l'~l~"'"~:--~-',1.Q.Q..9,k,..,:q~.-.,.. "., e ..~..,_".r ,t -.---~-~,.Q-"-z'T"~ ~ r~,~ .w,;s;"--

.. Non-perturbative Phases: [jet confinement - particle jets] --.--:. --~~~ /~;-~~--~~~~~"g~.!-;~~­--- ~~:;8~;=:-\/_---~~_ ..~il~~~, <~:

_.:=--O ~ ~,J.·.•Q:..'''-.·.1S~1 ,'.' . t:_ ',' ~~.'. -.., >-,,~~~~

phenomenological models to convert partons into primary hadrons ---- ccu-fC"o:'~~~~;-~" ,S-o/<", "'!"nn '?T:r ----

H d d._..-)4 / '-i,p \"'-(--<~

LKc a ron eceys -> ..,;;\ ~~.~O>,'i ~ \ ,--~J/IifV /-/ "-'/ "" '" ""-'-

phase-space or effective models to decay unstable into -:1l -/0;l.i'r,\ .,'''.. ~'": \,• ••• • i

stable hadrons as observed in detectors -;J':j .Ii'. ~ '.. . ..

VIo

:> predictions at hadron level - comparable to experimental data if corrected for detector effects

Jan Winter BNl, June 24, 2010 - p_2

'WI 'j" r~YY"Wlmrn7Tmn ;

Comparison with CDF data: W+jets production[T. AALTONEN ET AL., PRD 77 (2008) 011108]

.. Monte Carlos need to be validated and tuned against most recent Tevatron data.

.. Sherpa vs1.1.3 predictions normalized to total inclusive cross section. Two choices of PDFs.

.. Tree-level ME+PS can reproduce W+>=n jet xsecs to 20% after applying overall K factor.

300PT,1 [GeV]

W + jets

PT

1st jet

200

- CDF Run 2 data (2008)•• • • Sherpa 112 CKKW 3jet (cteq6m)

- Sherpa 112 CKKW 3jet (cteq61)

100

co1U"'C--

>IVCo':a~

..:c.

"'C13"'C

T_~

W + jets

320.pb-1

2 3 4Jet multiplicity (incl n jets)

......... CDF Run 2 data (2008)•••• Sherpa 112 CKKW 3jet (cteq6m)

- Sherpa 112 CKKW 3jet (cteq61)

o

10

s.~ 102

U.S+int~b

::c.s 103~ !i I

10_1~_ Tevatron, RU,n 2- I I I I / , I ! I I I 1--1ltl / I I " I

~ 0.4"'C 0.2

i 0 ~ 1.. ..:-·--- ·· ·:1 I jco -0.2l' -OAt! !!! ! [ !!! ! ! !!o~

VlI--'"

Jan Winter BNL, June 24, 2010 - p.3

~~ ;;; M:S:.~~c~~"~,;,,,@iitJW:-;(,;,,::;;,.,,dt,$i>>>,,&'~',,,~,,,, ~~:,\' ,.."'f.::":·:::,::t:~~~;:·,,,;~.,:::>0!::.>;c~~:'&,#:,:.,;: : : . , ,, : , : ,, : , : ; , . ,~ .%~ c:~%~: , : :~:; : : : : : ~::m: : : : : : . : : : :'?/~?~?:~~':f:\ : ,;\: : : :.f: : : . : ,:f~ , . " : ,, «~,i~:.,}?:", '%:;::.)!ki!_:;:;,,~,~-:,_i.~,_. M, 'i:i!"!!~d< ,.;.,,>-:.:,,:'Q:¥.{ ,. ~ %%,~::;:"h,-liA ., ,,:;,:,1ifibf9LJ "·;;dhM"h::'8:,;A:,Jk:d¥..:,::¥::~:,;}:'i:~l':,,A:~:::~:~ALA~,::JW

Comparison with CDF data: Z+jets productionME&TS :: COMIX + CSS [1. AALTONEN ET AL., PRL 100 (2008) 102001]

Jj Sherpa vsl.l [CKKW] (left) compared with Sherpa vs1.2 [ME&TS] (right) .

..., Examples of jet observables: new approach better describes the data.

.. Sherpa predictions multiplied by constant K factor, normalized to first-jet bin xsec.

l\jet3

-- Nmax=O

-- lVmax = 1

-- lYm a x = 2-- lYmax = 3

- data

2

F -"---==j

!

1

0.8

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~ 1.4::a

~ 10 4

...0 F

t.;J:lo.; 10 3

<J.)

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------t 102

b

2 3Jet multiplicity (incl n jets)

I i I

I->--< CDF Run 2 data (2008)

-T -.L - Sherpa 112 CKKW 3jet (cteq61)

Z/y + jets=- -

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1

- -

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Tevatron Run 2 !

I I II

l: I i I -:.-- -

~ -::

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;e...... 104

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+(1)(I)

t?-

N1? 102

! ~4~ ~2

: 0~ ~~y -~4o~

VIN

Jan Winter BNL, June 24,2010 - p.4

Z+jets production @ Tevatron Run2 energiesME&TS :: COMIX + CSS [HaCHE, KRAUSS, SCHUMANN, SIEGERT, JHEP 05 (2009) 053]

.., Merging systematics of total cross section (LO) has improved: flO"tot/O"tot < ±3%

.. Differential k T jet rates in Qcut = Qjet variation @ hadron level. Note N m a x = .5.

.. Qcut variation now within ±10%. Note J.L~ == M;e and 66 GeV < Ms; < 116 GeV.

==t=

2 2.5lOglO (dOl / GeV)

1.5

--==......

I I I I I

I I I

0.,5

-- QCllt = 20GeV~.._- Qcut = 30GeV

-- Qcut = 45GeV

0.8

0.6 r I I I I f I I I I [ J' I I I I I I I I I l

10- 3

10-4

.----.8~

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30 45Qcut/GeV

; . ..~

20

_LO~ Nmax =6

Nmax = 5~_- Nmax =4

Nmax = 3

- Nmax =2iEBffi Nmax = 1

1.02

1.0

0.98

0.96

6'H 1.0 4t;"<,b

VIW

Jan Winter BNL, June 24,2010 - p.5

'rrT"H terr']·· tTT'nrrn m 7

Recent comparison of LHe predictions for W+3jets[HaCHE, HUSTON, MAITRE, WINTER, ZANDERIGHI; LH09 PROCEED.: ARXIV:1 003.1241J

.. between BLACKHAT [BERGER ET AL.], ROCKET [ELLIS, MELNIKOV, ZANDERIGHI] and SHERPA [GLEISBERG ET AL.]

"II rather different scale choices at NLO yield> 20% deviations ... impact on BSM searches!

.II SHERPA'S ME&TS merging in good agreement with NLO once rescaled to NLO xsec

700 800 900Hr,tot [GeV]

____ ~.- _...."' ........ "'_, .T~.~,".~: ........

600500

I!

LHC 10 TeV

W+ + 3 jets lncl, production: HT,tot

! • i

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~ ..•• Sherpa, ME&TS(N",ox=2+4)

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o ~

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100 200 300 400

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~o

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250 300

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•• , •• c :•••••••• - •••:··L.r:..i

150

LHC 10 TeV

100

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50

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I' Sherpa, ME&TS (N x=2+4), ME-level'=i ME

!~:... '-l,...., ! . '=t·r- 'I-"""L-I .."..,l ~I ~

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,J

w+ + 3 jets incl. production: E of W+T

....Ql

~ 0.2_

! 0tn .jI

() -0.2~

~:aB

3:

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~.:1~ 10-2

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Vl.,J:::..

Jan Winter BNL, June 24, 2010 - p.6

m 77

."rr_W Boson Physics

andGlobal Analysis of PDFs

U'lU'l

C.-P. YuanMichigan State University

June 24,2010 @ BNL

Workshop onThe Physics of Wand Z Bosons

VI0\

Precision Electroweak Physicsat Hadron Colliders

Physics ofDrell-Yan, Wand Z Bosons

Vl-....)

W-boson physics

OW-boson production and decay at hadron collider

8 How to measure W-boson mass and width?

8 High order radiative corrections:

n:' QeD (NLO, NNLO, Resummation)

~ EW (QED-like, NLO)

e ResBos and ResBos-A

W-boson production at hadron colliders

VIO¢

partonmodel

~

lV

~ rpartonic "Born"-,

cross section of f J -+ W+

(Thh' .....W+X = L t' dx ldx2 {¢Jlh (xI) cTif'¢Jtjh' (X2) + (Xl +--t X2) }

i,i' 10 / \~_.......---.........

W-boson production at hadron colliders

w

V1\0

PDFs: probability of

finding a "parton"

inside the hadron

'K ,U �L---..

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q~

underlying events

(from proton remnants)

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colored) initial and

final states

can radiate gluons

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0\o

...PA

P -----l

...PB

P ----l

S ==(PA + PB)2

k==C;APA

I == ~BPB

_ 1 fd;A d;B (0" - 2S -Z:~ It/A ';A,Ji )It/n (!;n,Ji) -dO-

do-=IMI\2ny g(4)(q-k-l) d:q

'----.-..J ( 2ft) 2q0

ll>{dO" 2 =! fd~A dfn Ix (~A,Ji)jYn (';n,Ji)

qydydQ S ;A SB A

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Q2 \ ~A ~B

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0\......

111-.

Prospects and Future of theSTAR W Program

Joe Seele (MIT) for the*AR Collaboration

The STAR experiment is planning a number of upgradesand measurements that will constrain the polarizedanti-quark distributions in a polarized proton. TheForward GEM Tracker will add charged particle trackingin the forward rapidity allowing for charge signidentification and background rejection in the forwardrapidity region.

...

Af- = !. (au _ad).2· it d·

Xl == X2

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Ye

RHICBOS(Resummattcii:OS5V08DNSwK

- DNSaKKP

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delta-ubar

0\N

Ye

63

0'1~

· High gain ("'106)

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... , ·f:<':, ,.......,'

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00 0.5WaIl.lto H110:tt:!lI\~

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without FGT with FGT

The addition of the FGT will allow for charge sign identificationat forward rapidities

leptonlr1l<1: 2 beamst eff;;6.65 wI 9MHz RF, RunS QeD bckOt rhiCbOEHJW·,W '#82, 19 pblepton 1rI1=[1.2J: 1 baal'l'l. eff=O.60 'N' eMH:l RF, M-e QeD ookg, rhicbos OW·,W ·~.3, 4.7 pb

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F I I I f I I f

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...e 0"+ 0.~T>25GeV

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=t=.;':'i~~''::-~~

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+ /~/,rJJ> !

,·/r/'/'~ !'(~n;k"'./.{!..... .,...4.'~ r" W-

!!

f".~.JIIIN~"..J

RHIC is planning to run 500GeV polarized p-p collisionsin a multi-year effort toconstrain the polarization ofthe anti-quarks in the proton

Calculations assume thedemonstrated SiB (6 and 11)for the mid-rapidityprojections and 5/B"'1 for theforward and backward rapidityprojections

0\0\

-2 ..1 o 1lepton 11

2

0\......:J

Prospects of the Forward W Measurement inPolarized pp Collisions at

the RHIC-PHENIX Experiment

RIKEN Nishina Center for Accelerator-Based Science,Wako, Saitama 351-0198, Japan

Fukao, Yoshinori

RHIC-PHENIX experiment aim to measure AL in W -+ m process andimpose significant constraint on polarized anti-quark PDF with 500 GeVpolarized pp collisions. One of the major upgrade work is the developmentof new W trigger system, which consists of MuTRG and RPC. Wecompleted MuTRG and RPC3 North installation and will finish RPC3South installation during 2010 shutdown period. The commissioning of theW trigger system was performed with beam and cosmic ray, and finalperformance evaluation of full-chain trigger system is ongoing. In additionto the trigger development, new hadron absorber, which provide powerfulbackground rejection, is in-manufacture and will be installed in 2010.Offline analysis and simulation for W signal extraction are also in progresstowards coming physics run in 2011 and future.

W Trigger System

Trigger

MuTRG

Trigger • -Boa~

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. ..n····_·__·_·_·__·~·__··_···-····--_···_·-·_······ ~~- _ -..----.-~---._-.--..

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ts

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RPC Module Performance

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, 500/0 pol.)~ _ i i ~ ..

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·11 (muon pseudorapidity) II (muon pseudorapidity)~ ~

SIB =3.0 (optimistic) SIB =0.3 (conservative)

> Offline background evaluation using Run 2009 data andsimulation study to optimize event selection is ongoing.

> New Forward VTX detector will be installed and improve SIB.

AN of VV Production in Polarized p.p Collisions

Zhong- Eo KangRIKEN BNL Research Center, Brookhaven National Laboratory, Upton, NY 11973, USA

Much of the predictive power of perturbative Quantum Chrornodynamics (QeD) is contained infactorization theorems. They normally include two assertions: a physical quantity can be factorizedinto perturbatively calculable short-distance hard parts convoluted with nonperturbative long-distancedistribution functions; the unizJcTsahty of the nonperturhative functions. Predictions follow whenprocesses with different hard scatterings but the same distribution functions are compared.

The phenomenon of single transverse-spin asymmetry (SSA), AN == (a(5_d - a(-81..))/(a(81..) +a(-5J.) ) , defined as the ratio of the difference and the sum of the cross sections when the spin vectorS1.. is flipped, was first observed in the hadronic A0 production at Fermilab in 1976. Large SSAs, aslarge as 30%, have been consistently observed in various experiments involving one polarized hadronat different collision energies.

One of the approach to describe the observed SSAs in QeD is so-called Transverse MomentumDependent (TIvID) factorization approach, which factorizes a(81..) in terms of the TMD patton distri­butions and attributes the SSAs to the nonvanishing Sivers function, the spin dependent part of TI\'IDparton distribution. One of the most non-trivial feature is that the Sivers function could be processdependent (non-universal). It was predicted by Collins around. 2002 on the ba ..sis of time-reversal andparity arguments that the quark Sivers function in semi-inclusive deep inelastic scattering (SlDlS)and in Drell-Yan process (DY) have the same functional form but an opposite sign, a time-reversalmodified universality.

The experimental check of this time-reversal modified universality of the Sivers function wouldprovide a critical test ofthe TMD factorization approach and our current understanding of the SSAs.Recently, the quark Sivers function has been extracted from data of SlDlS experiments by Anselmiuoct. ol. Future measurements of the SSAs in DY production have been planned. In this talk, we presentthe SSAs of inclusive single lepton production from the decay of HI bosons, and show that the leptonSSAH is significant and measurable for a good range of lepton rapidity at RHIC. We find that the leptonSSA:-:: are sharply peaked at transverse momentum PT rv lvlw /2 with TV mass lvlw. This is becausethe most TV bosons at RfllC have or <.< lvlw. On the other hand, leptons from heavy quarkoniumdecay and other potential backgrounds are unlikely to be peaked at the PT ~ Mw /2. Since the Wproduction and DY share the same Sivers function, we argue that the SSA of inclusive high PT leptonsat RHTe if, an excellent observable for testing the time-reversal modified universality.

73

on-universality of the Sivers function

-f-()Co-(x.

m

m Different gauge link for gauge-invariant TMD distribution in SIDIS and

DY J' i· -P ']. ',. . (:,1 ~ ey 1I~71L) .':/- -s i kj~ ·Y ..:_ .~I---:'" - I ' . r ,; -- , rs -:::1('- ,/ /1 (L. k : . k/) --~-'-') -- (, '», :,1.1"/ (0 .0,) I Gauge link ~"ll i u . Y-l ) II). S). i / . ~- . (. 'i"........) .:J \... I· '. . ~- 'J ; ,u • - •~/l I ~. '.

: q)~ ( { +OC, O}, OJJ<I> ~J_ (+-x, {yJ_, OJ_} )<I>n ({+ex: , y-}, Y~L)

<p~J{-ex., OJ, O~)<p~~ (-x, {y~, O-l})<pn ( {-CX', y-}, Y-L)..L

-....).+;.

Wilson Loop - exp [-ig .h d.a':"r.;J Area is NOT zero

-- x

m For a fixed spin state:

SIDIS -+ -+

fqjhi (x, kl-' S) =I fqjhl (x, kl-' S)

June 25,2010 Zhongbo Kang, RBRC

Time-reversal modified universality of the Sivers function

-......lVl

II Relation between Sivers functions in SIDIS and DYFrom P and T invartance:

~TDIS -:-' D''" .-+

j' c.,-~ ', .. " (x' k , C,~) -,~ f ,I _. ir k - Q)qlll, .~ -1-' '<. --, qlh' \'(J~ _L; !J

• Spin-averaged parton distribution function is universal

From definition:

!qjhT (x, k J : 8) =!qjh(X, kd + ~,6.N !qjhT (x: kL) 8· j5 X kl­If§ One can derive:

!\ IV fSIDIS (. fro ) ..- i\ lVfDY (,y. J~ )Ll. ,J q / IL -, •.C. fL -..L ~- - L-\ q / h ,-.-0; 1!_L

Most critical test for TMD approach to SSA

June 25, 2010 Zhongbo Kang, RBRC

Intuitive understanding of the sign change

111I Difference between initial and final state interactions

j=I!!

:';.·~.;;i;~;~';;;

~:

-......l0\

pI" + P ~ [r* ~ R+ R~- ] + X

DY: repulsive

f+p' ~R+7T+X

SIDIS: attractive

;'\ J.Vf·S~D}S ('I" 1.~ i ) = ..~ /\ JV f·DY.~ (x': k I )L.l q/h, .1/~"'-,-_ Ll -l qf h. ".---L

II Sign change:w !t=:\cr of TMD factorization

m Test of current understanding of SSA

June 25, 2010 Zhongbo Kang, RBRC

SSA of lepton from W decay: rapidity dependence

IJ SSA of inclusive lepton is still sufficient for measurement:

<t.Z 0.1. I

ir,~',kd,'5

<t.Z 0.04 r'-------------,

..0.03 "I!! 1., Pr! " "!!! " 111 II 1" 1111' p'!l' .,t,! " I" "I

-2.5 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 2.5

Y

-.....)-.....)

f.!- (e-)0.08

PT=41GeV

0.06

0.04

0.02

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Y

0.03

0.02

0.01

o

-0.01

-0.02

\.>~

~+ (e+)J,,/

p~;;41GeV

• Good flavor separation:ill 11-(e-) at central-forward rapidity is sensitive to d Sivers function

m 1J+(e+) at forward is sensitive to u Sivers function, at backward is sensitive tod-bar Sivers function

June 25,2010 Zhongbo Kang, RBRC

SSA of lepton from \N decay: PT dependence

II PT behavior of SSA of leptons:

4~! I

20 30 40 50 60 70

PT

!~

f ~nV=-1.2

..... ~..~ ~ ..

o r·.....~.~.~.:.:.:.:.~.~.~.: ---J--------~.....- ]

0.03

0.02

0.01

-0.01

Z<t.

o,, ! , I ! " ! I , " ! ! ! J ! , ! , , ! I I " ! ! ! II I , ! , ( ! ! ! J II ! ! ! [ ! ,

y=1.2

PT30 35 40 45 50 55 60 65 70

0.05

0.04

0.03

0.02

0.01

<t.Z 0.06 r'-------:------------

-......l00

w inherit the key features of VV asymmtry

m sharply peeked around pT tVMw/ 2, should help control the potential background

June 25,2010 Zhongbo Kang, RBRC

.......:J\0

Ulrich Baur

Precision Measurement of the lV Mass and New

Physics

1. Why?

2. ~V Mass: Status and Measurement Techniques

3. Status of Theory Calculations for W / Z Production

4. Conclusions

Ulrich Baur

State University of New York at Buffalo

The Physics of Vv' and Z Bosons, BNL 06/25/10

00o

11- Why? I• The LHC is a discovery machine. Why should we measure the lV

mass, and more generally, do precision physics at such a facility?

• After all a precise measurement of M yv in a hadron collider environ­

ment is no walk in the park (see talks by Ashutosh Kotwal, Junjie

Zhu)

• more bluntly:"I rather commit suicide than measure Mw at the LHC"(Guido Altare11i

at an early LHCC meeting)

Ulrich Baur The Physics of Wand Z Bosons, BNL 06/25/10

00~

• Which measurements are of interest?

~ mt, Nlw and sin' Ovv

-+ make it possible to constrain the mass of the SM Higgs boson:

winter 2010: M H < 155 GeV (95% CL)

one-loop corrections to Mw and sin2 Ow depend logarithmically

onMH

~ thus providing a consistency check on the SM (once a Higgs boson

candidate has been observed)

-+ may give hints ofnew physics, or provide constraints on new physics

models

new particles contribute to the one-loop corrections

Ulrich Bam The Physics of Wand Z Bosons, BNL 06/25110

Data in better agreement with SUSY models than SM

but this is not surprising as SUSY models have more free parameters

200190180170mt [GeV]

160150140

80.60uncertainties 68% CL:

80.50

80.30 r;..:.'... . ..... .: .....;.

80.20

>(])~

S 80.40:2

300

MH [GeV]

250200

-----------,20Theory uncertainty

- Fit includIng theory errors

150100

CMSSM: Constrained MSSMNUHMI: a common SUSY-breaking contribution to the Higgs masses is

allowed to be non-universal

10

'" 12::j

00tv

Ulrich Baur The Physics of Wand Z Bosons, BNL 06125/10

Wand Z Production has been observed at the LHC

W--+ev candidate--------------------------------+-......r.--------

.:..1.~~:'~,~1t ,

~.".

....

• •,..

\-~--*"" ..ll"t..",.

eMSExperiment at LHe,CERNRun 133874, Event 21466935lumi section: 301Sat Apr 242010, 05:19:21 CEST

ElectronPT= 35.6GeVlcMET := 36.9GeVMr = 71.1 GeV/c2

•,t •

... ~.l .•. , ...•~.~ ,.

~,~~~~;~

00VJ

Ulrich Baur The Physics of Wand Z Bosons, BNL 06125110

00.,J:::..

Ulrich Baur

14 - Conclusions I• l\IIw , together with mtop, make it possible to constrain the Higgs bo­

son mass

• need bMw == 0(10 MeV) to match anticipated precision for mtop

• sensitive to new physics via loop corrections

• measuring l\!I~~/ at the LHC is non-trivial and may require special

runs (deuterium, helium) and/or special detector configurations (re­

verse magentic field)

• EW radiative corrections affect the MT line shape and thus the W

mass extracted from data

• need better understanding how to combine calculations of QeD and

EW corrections into one unified generator

The Physics of W- and Z Bosons, BNL 06/25/10

85

000\

UTLINE

~Motivations

~l$Cross-Sectionsat 7 TeV and expected event

.Yield

~~ Asymmetry Measurements

~~w.mass prospects

~:~ First W results from ATLAS

lOMe\!

1"..11"..1

1"..11"..1

EAK

!(m;op, loqmi;

~mw

~mw

mw

'185'180

lSIECTRO

Sfd I',,:;·.,,;;.d

r.l55M ~:'::::Cy

both models k1i':if ir81

'l70 175mt[GeV]

Heinemeyer, HoOlk,Stockinger, Weber, Weiglein '09

165

E

experimental errors 68% CL

-- LEP2fTevatron (today)

-- Tevatron/LHC

- ILC/GigaZ

'160

8020

00........:J

Friday, June 25, 2010

103

Mx (GeV)102

0.0 I I , , II.. " '.. .. ,~...' ,

MSTW2008NLO

0.2

0.6

0,8 i j , , , 1 i , i' Iii i I I

ratios of parton luminositiesat 7 TeV LHC and 14 TeV LHC

.Q~.?:'"w 0.4oc"E::I

TEDECTIONS

At7TeV

(JNNLO(W~lv)=lO.45nbroughly x2 at 14TeV

lIIIII!IIIeROS10"

:::: ~Vlot

Tevatron LHCI(t

10

I o~

10

0010: ~ (ij./E.1,t> '.5/20)

00

10

,,,{. [,. I

<i.B,(Etl

> 100 GeV)

10

to':

ro ~ (It

IO~ r cr"(~,',, >:/~)10" ITj '/9:l.(M,j - 150 Levi)

10'"

IU0.1 I 10

\"S

Friday, June 25,2010

2010-2~ I, !

o

10-1

~10~' , [ 'A~~' '('\'1Iii Ii I l~~e~e' Il(J) ····QeDC 50 pb-1 --W'tV1:Q)

> ., .;., . " -Zee

"; 1 --::''i!'' -''.Ji}\'-''f:;:;:i};,

_ __ WJmA:)I:.~TIMEASUREMEN.TS

~~2-.50/oafter1 fb-l

~~5·o/o·after -·50 _pb- 1

~~ PT > 25 GeV lepton

~~MissingEt >25 GeV

~Expected uncertainty(stat4-S'¥s, no .lumi):

00\0

Friday, June 25, 2010

\0o

UMMARY

~, LHC will offer unprecedented numberIor a variety of studies:

~~ Detector Commissioning

~~FrecisionElectroweakFhysics

~~. Backgrounds for 'new' physies

~~..Just..gettingstarted but

The Physics of 117 and Z BosonsRIKEN BNL Research Center Workshop

June 24/25, 2010

Current Status and Prospects for lV andZ Cross Section Measurements at CJ\1S

Carsten Magass1

(for the CI'v1S Collaboration)

III. Physikalisclles Institut ARWTH Aachen

D-52056 Aachen (Germany)

Abstract:

Current status and prospects for HI and Z cross section measurements at eMS arepresented. Events have been selected in electron and muon channels, and candidatel'V and Z decays have been examined. The measurements or the cross sections arein progress, and details of lepton identification, missing energy measurement, andevent selection are described. Furthermore, prospects for future measurements arepresented, like the measurement of the Z boson rapidity distribution and the muoncharge asymmetry in TV decays. Finally, selected studies of IV!Z boson productionin association with jets are discussed.

G~vlS Physics Results Webpage:https://twiki.cern.ch/twiki/bin/view/CMS/PublicPhysicsResults

Imagass@physik.rwth-aachen.de

91

CMS Performance Roadmap

•500k•5Dk•5000•500

Cer-stenMngoss :;: June 25, Z010 ::: W/Z@ BNL - B ~

1 nb' 10 nb-I 100 nb-1

• •5000 50k

I .Candidateh\.l1M'ji@@l1nWi'1&'F •

j ~'f==T-~---J oow/Gw'(40I7JniJl1F~:r ~---- f i data-driVehl'ltet~

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W.~ ev/~v •

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HF=99.fK:J, HO=96_9<!,::'}29.3

~~.~ I

Ccrsten Mll9G$S ',:; JIJf'e25, 2010 ',:: WIZ e BNL

eMS Preliminary

w~ /l V: Candidate Event

RW1H -9-

w ~ /l V : Selection

Selection'1 Muon with Pr) 25 GeV in 11]1 (2,jSQlated(tracker),muonfired trigger

~-~muo( ~._._.}._~F=PVT

hadf~~~/

hleutr'ino escapes-" observe missing energy in

rrcnsverse plane (MET) 20 " 00 3"'00120140160 1'j) >00

Reconstruct : --_~ Mr (GeV/c 2)

Transverse mass m; == ~21trPf.(l-cos,drp)

Ctlrst<1:r. MQ90S~ :"; June 25, 2010 W!2'2 ~NL

w~ Jl v : Data - Monte Carlo Comparison w ~ JlV : Matrix Method

Contributions from QCD processes difficult to predict-7 Estimate from data using the Matrix MethodEWKCross sections:

MCFM NLO usingMSTW06 NLO PDF

Variable 2

Signal{isoicted murms)

QeDBackground(l,lSlAillyrot Isclcted)

CQrst~Mogasz

,-

92

VI!Z@aNL

-.1.~~~';~~(

\ .",

fT:R~-~-'J CMSExp@nment at LHC.CERN

1.¥.·.••;.~.·••..•...•...••.?•....1(•.•..•.•./•.•...f.'..J.n.1Rim133374.e",,",21_935~~~f~ ~~::~~~~'~~'92'em

8ectronPT:::;35.6~VIc.

M£T"".36.9GeVII,h=71.1 ~V/(~

W -7 e V : Candidate Event

Very good agreement '

MUO~~~fO!~~:-=---...)~.•1l~~:~~~e~~~~·o~ all ~ ~

~ ,I'" ~~..~,., ,

~ I

.0.2 -t,"H .0.1 .(J,e .. a.os •.1 a.iS 0.2

Transverse impact parameter "i;;l.RWIH " . Co~nMo9'lS:; ." JuntZ5.Z0lO ::. W/Z@BNL -13 - ~

W -7 e v : Selection W -7 e V : Data - Monte Carlo Comparison

Selection:single electron trigger fired, 1 Electron with PT > 30 GeVin I'll < 2.5,identified via track matched to ECalcluster (GaussianSum filter)and cuts on shape variables, veto on further electrons with PT > 20 GeV

RWIH CorrtenMogc;s:i

Extract QeD backgroundfrom dot!?,

W -7 e V: Template Method Electron Performance (1)

MET sensitive to everything (real objects. noise) in the detector

~ Use Z events as templates U to estimate MET in W events

$0.06 Me .ft.- ~e~o~: ~~~;i:ctron in ~ 000 jJ ~ JUR".,,·- :ake different kinematics ~ 0..04 !\ MET from W 7 ev

Into account. . 'B 0.031 ) eeereetee MET4: :fromZ~ee002 I

-7> Good description of MET 0.01 10 TeV

I\J 10 20 70 00 90 100i!rIGeV)

RWIH W/Z@BNL - 17-

Gaussian Sum Filtermakes use of high granular trackingDetectors (track seeding)

Level 1 trigger efficiencyL1candidate found offline?

Nommo.i trlg9~r threshold: 2 GeV

93

z ~ J.l J.l : Candidate EventElectron Performance (2)--------,---------------.-------

Isolation variables nicelydescribed by Monte Carlo j

RWIH CcestenMo9'JSs .: June 25, "2.010 :.~ W/Z@ B1\Jl -zo-

z ~ u J..l : Selection z ~ J.l J.l : Data - Monte Carlo Comparison

Muon

AZ decays provide suchsamples used for muon ~(and electron) efficiency;;mecsurements • ,2

«: f~~~·rrillMeasure efficiencies from data~ CMS P'rullmlnl'l)' 2DI. •

~ 1........"":.,;;;H.. uSingTa9-and-Probe Method

~ ![].. ~:::.~ QCD~10·r

r j

l°l ~1Q"~ "good" Muon

rQ Tracker -==~:i.;.if

Muondetector -Statistical precision-0.5'70 with 100 pb-I

Selection:2 Muons with PT> 20 GeV In 11]1 < 2,isolated (tracker), opposite charge,>= 1 Muon fired trigger

RW1H UJrst~n Mo90SS ::; Jut'le 2~, 2010 :: W/Z e 6N1.. -Zl- RWIH

Carster1MogoS5

z ~ e e : Selection

Efficiencies again viaTag-and-Probe Method

Eff rcrencrese.,~ tz ->'Vl00~OJ

~, - 90 ';'0 ,[ ct 0 <" 1 • ( .: - (1 ~ <.,~r )

=82 Q,c

tAcceptance 40!~

Ldt_10pb-'

Selection,single electron trigger fired, 2 Electrons with PT> 20 GeV [TIl < 2.5,identified via track matched to ECalcluster (GaussianSum Filter)and cuts on shape variables

f:lectronsPr""" 34.0, 3191;reV/(trw.mess c:91.2Gr:V/cl

z ~ e e : Candidate Event ..._,_-.......... .~.~_ .... ._......__..... ~_...___ .... _.... .._'__ ....._,... ,__• ~.~_...__.J" ....

--~I/' -~"

94

this is just the beginning

Z -7 e e : Data - Monte Carlo Comparison

Carsten Magas.<;

Z -7 e e : Rapidity

Cros~-~:~::n-:~-i:~~~:~---- --- ~w~:c

of Z Bosonrapidity y ~ !In E + P,2 E-p,

-? Constrain PDFuncertainties

·25 -""r:>tenMQ~ :;: JoJnC 25, 2010 ::: W/Z@ Bt\l

Muon Charge Asymmetry A('!) ~ ~~:: _-:::~~::~~~ :~~:~ :'::; Wand Z with Jets

Gar'StenMagass JIJt"\e 25. 2010 W/Z@ BNi

MuonpsatJdorapidityMatrix method for QeD Dominant systematic uncertaintiesBackground estimatian due to efficiency measurements~i

R'IlIH Cllrstt::n Mcgass :': June 25, ZOlO ;",: W/Z@ BNL - 27 - ~:~

Important channels:- test QeD- background for searches- Jet Energy Scale

(Z + Jets)

W/Z + Jets analyses needestimates of :- Jet Energy Scale- QCDbackground- top background (!)

;(w IZ ~(~; + 1)Jet;r ""(J(W I Z + 7\" ]et;,) "" a,

-28-

Z + Jets: Tool for New Physics

95

z (~ ee, JlJl) + bb : Outlook

U1r.litel'l Mu~s ;;: Jorw: 25, 2010 :" WIZ@ BI\!L

.....;0;.::6: ... ,,'; x ... &>",~ W " • <" ~.,.->ifo"

Requires two b-tagged Jets

~l-31-gWIZI!Ht-l..

... Yo ;.;.:.;.:-:. r ~ ;..;«

Very good agreement betweenData and Monte Carlo <

..700rs~~~-~T:-;;;;'~Jet Performance < 600 "..nov flfil ..........~

P~25'~V

~~-----;~~~=::: -500 ~I~~

Jet Algorithm: f ,~:'::;~vParticle Flow 2500 '~',"il<'

anti-kt R =0.5

WIZ@SNI..

MET Commissioning <-> Understand Detector

---------~~-.-;-;;;:~~:~:'-) fake MET

Tag the noisy eventsand apply cleanup:

!::t;.,r:·----i --j !i'-f .""".nov

·:r'.'Qd]i I

.". ~j r ,

'1-:~~;n1d:\~::.;,;,

~~<,

NOise In the ECa!~ caused by heavily IOniZing ,

particles In the APD

":: W/ZeSNL

tj~·-"···'~:':_·"':~:::.',"':"-5§j

~ o'r . .' . Anti-kt 0.5;>"'1 • PF~;;wi . PT) 40 GeV

"",' .• 1111 < 1.5

""0-2 ·1.5 -1 ~LS ~ ~1f'1 ~

W/Z@~I\L

Presented a robust programfer start-up @ eMS

Summary

A'~;I;~'~~~/~;c I~~';e Wandk~Z events essential

understand detector- measure efficiencies- test data-driven methods- cross-check lumlnositv

I}\;AtU)~? @[jj}~~'t~ ®If'~g~

QQu~~;W~;£1

Ccesten Mc:!JOSS .. JfS>;e Z5. 2QjO ;:: W/Z@ BN:..

. "

Very good agreement betweenData and Monte Carlo

96

\0-....l

.TneStatus.ot fNfN'[J::J 'ffticrJ,lsforWIZ Production at Hadron

Colliders

FrankPetriello

University ofWisconsin, Madison

The Physics ofW and Z BosonsJune 25,2010

St~.d~EdCaftid];es

(0) " . , (Xs{fLR (1)., ,(, (XS(PR»)2 (2) )a(tim /-iF) = a' (tiF) + ' •.. a' (/-iR, /-iF)+' •. ' ..,. ". a ··(J-lR, J1F

1f ' 11

pp ~ (Z,I'*)+X at Y=Q

~ ~Z production knownthrough NNLO in pQCD

~ Residual theoreticaluncertainties from scalevariations <1% on inclusivequantities

f "Gold-plated" observablessuited to high-precisionmeasurements

:c..:.,x:::. ...::....

LO

NNLO

pdfs

f.LF = fl-R = I..tf-lF = f.L, f.LR = M

f-lF = M, f.LR =

1.0 2.0 30 5.0

!LIMNlelntk0v, FP (A.DMP)hep-ph/o3I2266

80 r f ( ii ! i (i 1 i i tiiliiiilliiitiiilill litl ii' f i

70 r ..- _., ... l

60

50

1..000

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2.5

40

YS = 1.8 TeV

20!-- 66 < M < 116 GeV ~~. M/2;;i; j.L ~ 2MJ'0C~F'ld~ta ,C

3:! ,lU,m:,,el;r~r,~~ttt~) ~ I

0.0 0.5 1.0 1.5 2;0

y

,Generally good agreementwith CDF/Do data

LO

80

60

;>-<'0<,

t:>"0

,......,,.a0..

'---'

0.25 0.50 0.75 1.00 1.25v,l.

LO

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A]).N1Phep-ph/o306 t92

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~ M=BGeV

MRST2001 pdfs

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~.,.•...............",.,."""" •. ",.,'.<.•)'.• ;r.,.'"~""'' '"' "..

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with spin correlations,

11(1 < 2.5, liT > 20 GeV;

11(1 < 2.5, liT > 20 GeV.

PI' > 20 GeV .

Pr > 40 Ge\T .

Tevatron LHe

LO NLO !\:lCi(jNLO LO NLO 1IC·.~!iNLO

~Cut 1 0.409 O.:l85 0.:383 0.524 0.477

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• Cut 1 :

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LHC 7+Z

Need V-jet at NNLO forthis region Boughezal, Gehrmann­de Ridder, Ritzmann 1001.2396

~-'-T-'T r I ~T~--'-' " I I

LO Z contributio"""<""""<"",' !' ends at pT=Mz/2

e, I,

oilro '~'\

"'l, -.~, -,

L''- \

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PT.I, ». Pr.e

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0.050

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0.010

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20

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oo~

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Mz,/2 & '11'~ 2Mz

percent-levelm''ternictions foracceprances

,.....o,.....

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'it: i'j

1\,,,",,"" .",,,,,,,,,, ,. ., ,IL.

o 5 c 5 c~

i

I I

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102

D~.HLctJ,

j~~!~nativ-~ •.:S~~~~f1~~~~ ••,~froacht() ·mooi11~gIR singulafitieS' .at ...~~L() Catani.Cieri, Ferrera, de Florian,Grazzini °9°3.2120

30,.,----r-< I

MSYI'f2008y's=1.96TeV

o20 30 40 50 60 70 ao 30 40 50 60 70 80

PTmin (GeV) PTmllX (GeV)

pp .... (z+I'~)+X ....e+e- +X

25 L. J1.r=J1-R""' IDz

20

'2 ~ ••-- NNLO

:.a<, 15

----NLO

.0p,

b

10

100

>25 GeV

-o:0~'p;,

b

I---l

ow

104

The Physics of Wand Z BosonsJune 24-25, 2010

Registered Participants

Name Affiliation E-Mail Address

Yasuyuki Akiba RIIffiN akiba@bnl.govLeandro Almeida BNL leandro.g.almeidaergmail.comJan Balewski MIT balewski@mit.eduKenneth Barish UC Riverside Kenneth.Barisheaucr.eduUlrich Baur SUNY @ Buffalo baur~buffalo.edu

Alexander Bazilevsky BNL shura@bnl.govAndrew Beckwith Amer Inst of Beam Energy Propulsion beckwithrgaibep.orgKevin Black Harvard Univ kblack@}fas.harvard.eduRadja Boughezal Univ of Zurich, Switzerland radja.boughezal@}physik.uzh.chKieran Boyle RBRC kboyle@bnl.govNing Chen Stony Brook Univ chen@}max2.physics.sunysb.eduMickey Chiu BNL chiu@}bnl.govMichael Daugherity Abilene Christian Univ mike.daugherity@acu.eduHooman Davoudiasl BNL hooman@}bnl.govSally Dawson BNL dawson@bnl.govAbhay Deshpande Stony Brook Univ abhay.deshpande@stonybrookeduChee Sheng Fong Stony Brook Univ fong(a}instLphysics.sunysb.eduYoshi Fukao RIKEN fukao@}riken.jpCiprian Gal Stony Brook Univ chip.ef@gmail.comThomas Gehrmann Univ of Zurich thomas.gehrmanneaphysik.unizh.chYuji Goto RIKEN goto@}bnl.govWlodek Guryn BNL guryn@bnl.govMarco Guzzi Southern Methodist Univ mguzzi(a}physics.smu.eduJohn Haggerty BNL haggerty@}bnl.govPrerit Jaiswal Stony Brook Univ prerit.j aiswal@!gmail.comZhongbo Kang RBRC zkang@}bnl.govDavid Kawall RBRC I Univ ofMA kawall@bnl.govJennifer Kile BNL jenkile@quarkphy.bnl.govWilliam Kilgore BNL kilgore@!bnl.govAshutosh Kotwal Duke Univ kotwal@fnal.govHye-Sung Lee BNL hlee@bnl.govSookhyun Lee Stony Brook Univ shlee@bnl.govCarsten Magass RWTHAachen magass@physik.rwth-aachen.deWilliam Marciano BNL marciano@bnl.govThomas McElmurry BNL tmcelmurrygaquark.phy.bnl.govDavid Morrison BNL morrison@!bnl.govPavel Nadolsky Southern Methodist Univ nadolsky@physics.smu.eduShigemi Ohta IPNSIKEK+SOKENDAI+RBRC shigemi.ohta@kekjpKensuke Okada RBRC okada@!bnl.govFredrick Olness Southern Methodist Univ olness@smu.eduKwangwoo Park Southern Methodist Univ kwpark@mail.smu.eduZohreh Parsa BNL parsa@!bnl.gov

105

Abid Patwa BNL abid~fnal.gOY

Michael Peskin SLAC Natl Accelerator Lab mpeskin@}slac.stanford.eduFrancis Petriello Univ of Wisconsin frankjp@physics.wisc.eduMarc-Andre Pleier BNL mpleier~bnl.gov

Jianwei Qiu BNL jqiu~bnl.gov

Guy Roche LPC-Clermont France roche@in2p3 .frRenata Rodrigues CBPF renatar@fnal.govAndreas Scharf SUNY at Buffalo abscharfeabuffalo.eduJoseph Seele MIT seel~j~mit.edu

Amarjit Soni BNL soni@bnl.govDavid South TUDortmund david.southeadesy.deJan Stark LPSC Grenoble stark@}in2p3 .frJustin Stevens Indiana Univ stevens4@}indiana.eduChristian Sturm BNL sturm@bnl.govBernd Surrow MIT surro\y~mit.edu

Swadhin Taneja Stony Brook Univ swadhin. tanega@}gmail.comMichael Tannenbaum BNL mjt@bnl.govRusty Towell Abilene Christian Univ rusty .towelleaacu.eduKathryn Tschann-Grimm Stony Brook Univ kgrimm@}grad.physics.sunysb.eduAlessandro Vicini Univ of Milano alessandro.vicini@}mi.infn.itDoreen Wackeroth SUNY @} Buffalo dow@ubpheno.physics.buffalo.eduJan Winter Fermilab jwinter@fnal.govScott Yost The Citadel scott.yost@}citadel.eduC.-P. Yuan Michigan State Univ yuan@pa.msu.eduFengYuan LBNL fyuan@lbl.govGuang-Da Zhao Peking University ktchao@}pku.edu.cnJunjie Zhu Univ of Michigan junjie@}umich.edu

106

The Physics of Wand Z BosonsBrookhaven National Laboratory

Physics Department Large Seminar RoomJune 24-25, 2010

Thursday 24 June 2010

09:00->10:40 Session I [Convener: Jianwei Qiu (BNL)]

09:00 Welcome Remarks Nick Samios (RBRe)

09:10 First Measurement of W+/W- Boson Production at STAR Jan Balewski (MIT)In Polarized pp Collisions at RHIC

09:50 First Observations at PHENIX of W Production From David Kawall (U. of Massachusetts,Polarized pp Collisions at RHIC Amherst)

10:30 Coffee

10: 50 - >12:10 Session II [ Convener: C.-P. Yuan (MSU) ]

10:50 QCD Resummation on A_L of W p_T Distributions and PDFs

11:30 W Mass Measurements

Pavel Nadolsky (SouthernMethodist u.)

Alessandro Vicini (U. ofMilan)

12:10 Lunch at Berkner Hall

13: 30- >15:30 Session III [Convener: Abid Patwa (BNL) ]

13:30 W/Z Physics from HERA

14:10 W Mass Measurements at DO

14:50 W Mass Measurements at CDF

David South (DESY)

Junjie Zhu (U. of Michigan)

Ashutosh Kotwal (Duke U.)

15:30 Coffee

15: 50- >17:50 Session IV [Convener: Kensuke Okada (BNURIKEN) ]

15:50 Monte Carlo Modeling Issues for W Measurements Jan Stark (LPSC, Grenoble)

16:30 Theoretical Issues in Monte Carlo Modelling for W Production Jan Winter (Fermilab)

17:10 W Boson Physics and Global Analysis of PDFs C. .p Yuan (Michigan State u.)

18:30 Workshop Dinner: Cookout at Brookhaven Center

107

Friday 25 June 2010

09:00->10:20 Session V [Convener: Abhay Deshpande (Stony Brook U)]

09:00 Future Prospects of the STAR W Program in Polarized pp Joe Seale (MIT)Collisions at RHIC

09:40 Prospects of the Forward W Measurement in Polarized ppCollisions at the RHIC-PHENIX Experiment

Yoshi Fukao(RIKE~

10:20 Coffee

10: 50- >12:10 Session VI [ Convener: Frank Petriello (Wisconsin) ]

10:50 A_N of W Production in Polarized pp Collisions Zhong-Bo Kang (RBRC)

11:30 Precision Measurement of the W Mass and New Physics Ulrich Baur (U. at Buffalo)

12:10 Lunch at Berkner Hall

14:00->16:00 Session VII [Convener: Sally Dawson (BNL)]

14:00 W Measurements and Prospects at ATLAS Kevin Black (HaNard)

14:40 Current Status and Prospects for W & Z Cross Section Carsten Magass (RWTHMeasurements at eMS Aachen)

15'.20 The Status of NNLO Tools for W/Z Boson Productionat Hadron Colliders Frank Petriello (U. of Wisconsin)

108

Additional RIKEN BNL Research Center Proceedings:

Volume 98

Volume 97

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Volume 93

Volume 92

Volume 91

Volume 90

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Volume 62

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Volume 60

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Volume 58

Volume 57

- Saturation, the Color Glass Condensate and the Glasma: What Have we Learned from RHIC?, BNL, May 10-12,

2010 - BNL-94271-2010

- RBRC Scientific Review Committee Meeting, October 21-22, 2009 - BNL-90674-2009

- P- and CP-Odd Effects in Hot and Dense Matter, April 26-30, 2010 - BNL-94237-2010

- Progress in High-pT Physics at RHIC, March 17-19, 2010 - BNL-94214-2010

- Summer Program on Nucleon Spin Physics at LBL, June 1-12, 2009

- PHENIX Spinfest School 2009 at BNL - July 1-31, 2009. BNL-90343-2009

Unk: .E:tU;;~lXSJQtnJ:~s"t:,;],(;,t19i:),.t?c,Q,Q~,~3?"a[~"L

- PKU-RBRC Workshop on Transverse Spin Physics, June 30-July 4, 2008, Beijing, China, BNL-81685-2008

- RBRC Scientific Review Committee Meeting, November 17-18, 2008 - BNL-81556-2008

- PHENIX Spinfest School 2008 at BNL, August 4-8, 2008 - BNL-81478-2008

- Understanding QGP through Spectral Functions and Euclidean Correlators, April 23-25, 2008 - BNL-81318-

2008

- Hydrodynamics in Heavy Ion Collisions and QCD Equation of State, April 21-22, 2008 - BNL-81307-2008

- RBRC Scientific Review Committee Meeting, November 5-6, 2007 - BNL-79570-2007

- Global Analysis of Polarized Parton Distributions in the RHIC Era, October 8, 2007 - BNL-79457-2007

- Parity-Violating Spin Asymmetries at RHIC-BNL, April 26-27, 2007 - BNL-79146-2007

- Domain Wall Fermions at Ten Years, March 15-17, 2007 - BNL 77857-2007

- QCD in Extreme Conditions, July 31-August 2, 2006 - BNL-76933-2006

- RHIC Physics in the Context of the Standard Model, June 18-23, 2006 - BNL-76863-2006

- Parton Orbital Angular Momentum (Joint RBRC/University of New Mexico Workshop) February 24-26, 2006 -

BNL-75937-2006

- Can We Discover the QCD Critical Point at RHIC?, March 9-10, 2006 - BNL-75692-2006

- Strangeness in Collisions, February 16-17, 2006 - BNL-79763-2008

- Heavy Flavor Productions and Hot/Dense Quark Matter, Dec 12-14, 2005 - BNL-76915-2006

- RBRC Scientific Review Committee Meeting - BNL-52649-2005

- Odderon Searches at RHIC, September 27-29, 2005 - BNL-75092-2005

- Single Spin Asymmetries, June 1-3, 2005 - BNL-74717-2005

- RBRC QCDOC Computer Dedication and Symposium on RBRC QCDOC, May 26, 2005 - BNL-74813-2005

- Jet Correlations at RHIC, March 10-11, 2005 - BNL-73910-2005

- RHIC Spin Collaboration Meetings XXXI(January 14, 2005), XXXII (February 10, 2005), XXXIII (March 11,

2005) - BNL-73866-2005

- Classical and Quantum Aspects of the Color Glass Condensate - BNL-73793-2005

- Strongly Coupled Plasmas: Electromagnetic, Nuclear & Atomic - BNL-73867-2005

- RBRC Scientific Review Committee - BNL-73546-2004

- Workshop on the Physics Programme of the RBRC and UKQCD QCDOC Machines - BNL-73604-2004

- High Performance Computing with BlueGene/L and QCDOC Architectures

- RHIC Spin Collaboration Meeting XXIX, October 8-9, 2004, Torino Italy - BNL-73534-2004

- RHIC Spin Collaboration Meetings XXVII (July 22, 2004), XXVIII (September 2, 2004), XXX (December 6,

2004) - BNL-73506-2004

- Theory Summer Program on RHIC Physics - BNL-73263-2004

- RHIC Spin Collaboration Meetings XXIV (May 21, 2004), XXV (May 27,2004), XXVI (June 1, 2004) - BNL-

72397-2004

- New Discoveries at RHIC, May 14-15, 2004 - BNL- 72391-2004

- RIKEN-TODAI Mini Workshop on "Topics in Hadron Physics at RHIC", March 23-24, 2004 - BNL-72336-2004

- Lattice QCD at Finite Temperature and Density - BNL-72083-2004

- RHIC Spin Collaboration Meeting XXI (January 22, 2004), XXII (February 27, 2004), XXIII (March 19, 2004)-

BNL-72382-2004

- RHIC Spin Collaboration Meeting XX - BNL-71900-2004

- High pt Physics at RHIC, December 2-6, 2003 - BNL-72069-2004

109

Additional RIKEN BNL Research Center Proceedings:

Volume 56

Volume 55

Volume 54

Volume 53

Volume 52

Volume 51

Volume 50

Volume 49

Volume 48

Volume 47

Volume 46

Volume 45

Volume 44

Volume 43

Volume 42

Volume 41

Volume 40

Volume 39

Volume 38

Volume 37

Volume 36

Volume 35

Volume 34

Volume 33

Volume 32

Volume 31

Volume 30

Volume 29

Volume 28

Volume 27

Volume 26

Volume 25

Volume 24

Volume 23

Volume 22

Volume 21

Volume 20

Volume 19

Volume 18

Volume 17

Volume 16

Volume 15

Volume 14

Volume 13

Volume 12

Volume 11

Volume 10

Volume 9

- RBRC Scientific Review Committee Meeting - BNL-71899-2003

- Collective Flow and QGP Properties - BNL-71898-2003

- RHIC Spin Collaboration Meetings XVII, XVIII, XIX - BNL-71751-2003

- Theory Studies for Polarized pp Scattering - BNL-71747-2003

- RIKEN School on QCD "Topics on the Proton" - BNL-71694-2003

- RHIC Spin Collaboration Meetings XV, XVI - BNL-71539-2003

- High Performance Computing with QCDOC and BlueGene - BNL-71147-2003

- RBRC Scientific Review Committee Meeting - BNL-52679

- RHIC Spin Collaboration Meeting XIV - BNL-71300-2003

- RHIC Spin Collaboration Meetings XII, XIII - BNL-71118-2003

- Large-Scale Computations in Nuclear Physics using the QCDOC - BNL-52678

- Summer Program: Current and Future Directions at RHIC - BNL-71035

- RHIC Spin Collaboration Meetings VIII, IX, X, XI - BNL-71117-2003

- RIKEN Winter School - Quark-Gluon Structure of the Nucleon and QCD - BNL-52672

- Baryon Dynamics at RHIC - BNL-52669

- Hadron Structure from Lattice QCD - BNL-52674

- Theory Studies for RHIC-Spin - BNL-52662

- RHIC Spin Collaboration Meeting VII - BNL-52659

- RBRC Scientific Review Committee Meeting - BNL-52649

- RHIC Spin Collaboration Meeting VI (Part 2) - BNL-52660

- RHIC Spin Collaboration Meeting VI - BNL-52642

- RIKEN Winter School - Quarks, Hadrons and Nuclei - QCD Hard Processes and the Nucleon Spin - BNL-52643

- High Energy QCD: Beyond the Pomeron - BNL-52641

- Spin Physics at RHIC in Year-1 and Beyond - BNL-52635

- RHIC Spin Physics V - BNL-52628

- RHIC Spin Physics III & IV Polarized Partons at High QA2 Region - BNL-52617

- RBRC Scientific Review Committee Meeting - BNL-52603

- Future Transversity Measurements - BNL-52612

- Equilibrium & Non-Equilibrium Aspects of Hot, Dense QCD - BNL-52613

- Predictions and Uncertainties for RHIC Spin Physics & Event Generator for RHIC Spin Physics III - Towards

Precision Spin Physics at RHIC - BNL-52596

- Circum-Pan-Pacific RIKEN Symposium on High Energy Spin Physics - BNL-52588

- RHIC Spin - BNL-52581

- Physics Society of Japan Biannual Meeting Symposium on QCD Physics at RIKEN BNL Research Center - BNL-

52578

- Coulomb and Pion-Asymmetry Polarimetry and Hadronic Spin Dependence at RHIC Energies - BNL-52589

- OSCARII: Predictions for RHIC - BNL-52591

- RBRC Scientific Review Committee Meeting - BNL-52568

- Gauge-Invariant Variables in Gauge Theories - BNL-52590

- Numerical Algorithms at Non-Zero Chemical Potential - BNL-52573

- Event Generator for RHIC Spin Physics - BNL-52571

- Hard Parton Physics in High-Energy Nuclear Collisions - BNL-52574

- RIKEN Winter School - Structure of Hadrons - Introduction to QCD Hard Processes - BNL-52569

- QCD Phase Transitions - BNL-52561

- Quantum Fields In and Out of Equilibrium - BNL-52560

- Physics of the 1 Teraflop RIKEN-BNL-Columbia QCD Project First Anniversary Celebration - BNL-66299

- Quarkonium Production in Relativistic Nuclear Collisions - BNL-52559

- Event Generator for RHIC Spin Physics - BNL-66116

- Physics of Polarimetry at RHIC - BNL-65926

- High Density Matter in AGS, SPS and RHIC Collisions - BNL-65762

110

Additional RIKEN BNL Research Center Proceedings:

Volume 8 - Fermion Frontiers in Vector Lattice Gauge Theories - BNL-65634

Volume 7' - RHIC Spin Physics - BNL-65615

Volume 6 - Quarks and Gluons in the Nucleon - BNL-65234

Volume 5 - Color Superconductivity, Instantons and Parity (Non?)-Conservation at High Baryon Density - BNL-65105

Volume 4 - Inauguration Ceremony, September 22 and Non-Equilibrium Many Body Dynamics -BNL-64912

Volume 3 - Hadron Spin-Flip at RHIC Energies - BNL-64724

Volume 2 - Perturbative QCD as a Probe of Hadron Structure - BNL-64723

Volume 1 - Open Standards for Cascade Models for RHIC - BNL-64722

111

For information please contact: Ms. Pamela Esposito Ms. Susan Foster RIKEN BNL Research Center RIKEN BNL Research Center Building 510A Building 510A Brookhaven National Laboratory Brookhaven National Laboratory Upton, NY 11973-5000 USA Upton, NY 11973-5000 USA Phone: (631) 344-3097 (631) 344-5864 Fax: (631) 344-4067 (631) 344-2562 E-Mail: pesposit@bnl.gov sfoster@bnl.gov Homepage: http://www.bnl.gov/riken

The Physics of W and Z Bosons

June 24-25, 2010

Nuclei as heavy as bulls

Through collision Generate new states of matter.

T.D. Lee Speakers: Jan Balewski Ulrich Baur Kevin Black Yoshi Fukao Zhongbo Kang David Kawall Ashutosh Kotwal Carsten Magass Pavel Nadolsky Francis Petriello Joseph Seele David South Jan Stark Alessandro Vicini Jan Winter C.-P. Yuan Junjie Zhu

Organizers: S. Dawson, K. Okada, A. Patwa, J. Qiu and B. Surrow

RIKEN BNL RESEARCH CENTER

Li Keran Copyright©CCASTA