CAMILLA DI DONATO SEZ. INFN NAPOLI ON BEHALF OF KLOE AND KLOE-2 COLLABORATIONS Hadron Physics at...

CAMILLA DI DONATOSEZ. INFN NAPOLI

ON BEHALF OF KLOE AND KLOE-2 COLLABORATIONS

Hadron Physics at KLOE and KLOE-2

Outline

C. Di Donato - Rencontres de Moriond QCD 2

Hadron Physics @ KLOE/2U-boson Search: e+e-/ULight Meson Spectroscopy: and physicsOther KLOE/2 results not discussed herePS Transition FF Physics: /f0(600) Study of (S/PS )

Pion FF from e+e- /

KLOE and KLOE-2 @ DAFNE

e.m. calorimeter resolution

d.c. performances

mm

m

z

xy

2

150

ps

GeVE

psT 100

57

GeVEEE %7.5


mm

pp

VTX

TT

3

%4.0

DAFNE: e+e- collider @ s 1020 MeV ; peak3.1 b

U

U-Boson Search


Low Energy Dark Forces


Several unexpected astrophysical observations (PAMELA, ATIC, INTEGRAL, DAMA/LIBRA, CoGent...) could be explained with the existence of a hidden gauge sector weakly coupled with SM through a mixing mechanism of a new GAUGE BOSON (U, A, V) with the photon:

• U mass range: 1 MeV – few GeV• Coupling constant of electric charge to U: 10-3

• U production/decay through photon mixing

[Arkani-Hamed et al. PRD79 015014 (2009)]

[Essig et al. PRD80 015003 (2009)]

Search for U boson @ KLOE


Meson Decays: U, U, 0 U … Peculiar of a light meson factory

e+e- collisions: e+e- U x-sec 1/s : 100 times higher at DAFNE w.r.t. b-factories/

compensate lower luminosity

h-strahlung: e+e- U* Uh If the hidden simmetry is spontaneously broken by a Higgs-

like mechanism, the existence of at least one other scalar particle , can be postulated h

Meson can decay to a U boson with: YXBRFFYUXBR XY 22

fbU 40 310,1 FFfor

Irreducible background: Dalitz decay l+l- , ( = 0.7 nb)

BRFFUBR22

e+ e- , with +-0

BR(e+e-)=1.15 10-

4 : produced events 106 e+e-

L = 1.5 fb-1

PLB706 (2012) 251-255


e+ e- , with +-0

• We have 14000 candidates: e+e- with + - 0

• Very small residual contamination from • MC Mee shape from VMD with FF slope from SND (213 events) [PLB504

(2001) 275]

Background extracted directly from dataC. Di Donato - Rencontres de Moriond QCD 8

PLB706 (2012) 251-255

Fit to Mee Shape

Using decay parametrizationfrom Landsberg85 and F(q2) approx. from Achasov, Kozhevnikov, Sov. J. Nucl.Phys. 55 (1992) 449

23

222

222

22

22

2

222

2

41

21

41

3

mm

qm

mm

q

q

m

q

m

q

qFee

dq

dqq

22

2

1

1

qqF

222

0

2

11

2

GeVmb

dqdFbq


Exclusion plot for

Kinematic factors [Reece-Wang, JHEP0907:051 (200)]

Opening of U+- threshold

0,,

,,2223

22223222

mm

mmmmF

U UU

2 10-5 @ 90% C.L. for 50 < MU < 420 MeV

Evaluation of UL takes into account:


PLB706 (2012) 251-255

PRL107 (2011)PRL106 (2011)

PLB706 (2012)

e+ e- , with /000

Preliminary studies on and 000 decay channels produce encouraging results

U.L. can be improved by a factor 2C. Di Donato - Rencontres de Moriond QCD 11

+- DECAY

Light Meson spectroscopy


Light Mesons: +-


Box Anomaly: are expected to get contribution from anomaly, Wess Zumino Witten term in ChPT Lagrangian

According to Effective Theory (HLS: Benayoun, Eur. Phys. J. C31 (2003) 525), they could be described by VMD + a direct term

/

+

-

VMD CT

+

Studies of final state interaction by unitarized extensions:

Picciotto, Phys. Rev. D45 (1992) 1569; Benayoun, Eur. Phys. J. C31 (2003) 525 Holstein, Phys. Scripta, T99 (2002) 55 Borasoy, Nissler, Nucl. Phys. A740 (2004) 362

Model independent method based on ChPT and dispersive analysis: do not fix relative strength between tree level contribution and resonance contribution

(Stollenwerk, Hanhart, Kupsc, Meiner and Wirzba PLB707 (2012) 184-190)

+- ++0

C. Di Donato - Rencontres de Moriond QCD

This analysis:L = 558 pb-1

2107 mesons

(4.6%

• Theory HLS-Model: (w = (56.31.7)

eV (wo = (100.92.8) eV

• ( = (604) eV [PDG] provide strong evidence in favour of BOX Anomaly 14

, +-

M

Even

ts/4

M

eV

2 clusters: |tcl-lcl/c|<5 2 Tracks closest to IP 1 clusters: E>250 MeV

Two body decays constrain E

Kinematic from decays constrain

Main background +-0

BKG feature: in the 0 rest frame are back to back ( < 165°)

TOF to reject e+e- background Signal in M+- window (539.5÷554.5)

MeVC. Di Donato - Rencontres de Moriond QCD 15

+-


Pmiss=Pφ−Pπ+−Pπ−

−Pγφ

missmiss PE

16

Data sample L = 558 pb-1

N =204 950

=(21.310.04)%; B/S=10% Signal counting from fit to E-P

pppp

EEEsE

Composition

Normalization Sample: +- 0


L = 558 pb-1

N =1´190103

=(22.770.02)%; B/S=0.65% e+e-=41.8 0.2 nb

BR() = (22.41 0.03 0.35)%

(systematics include: 0.5% (lumy)1%(x-sec.) 1% (evcl) 0,43% (cut analysis) = 1.56% )

Pmiss=Pφ−Pπ+−Pπ−

−Pγφ

PDG’10:BR() = (22.74 0.28)%

+- ++0


Measurement has been performed on L=558pb-1

•N=204´950 and N = 1´190´000• Systematics at level of 1.5%

0.00280.00050.1856

0±±=

πππηΓ

γππηΓ+

+

eV±=γππηΓ + )355(• Theory HLS-Model:

(w = (56.31.7) eV (wo = (100.92.8) eV

• ( = (604) eV [PDG]

+-


Fit with Model independent method based on ChPT and dispersive analysis: (Stollenwerk, Hanhart, Kupsc, Meiner and Wirzba PLB707 (2012) 184-190)

d/

dM

Dipion Invariant Mass

sms

sssmm

s

2

33233110

41

23

1

ssFsAP

ds

dV 0

2

ssP

ssssFV

1

)14.080.13()01.013.2()01.012.2(1 32

ssFsAPs

sd

d

V 0

2

2

1


PLB707 (2012)

202.059.025.089.1 GeVWASA

NTeo (taking into account efficiency and smearing)

Nbin

i i

Nbin

jijj

Teoj

datai SNN

12

2

2

ssP 1

202.040.008.031.1 GeVthsyststat

Dipion Invariant Mass

Ndata

PRELIMINARY

[WASA Coll. PLB707 (2012) 243-249]

6783

2

Ndf


DAFNE-Upgrade

New scheme

Old scheme


DANE upgrade -New interaction scheme: large beam crossing angle + sextupoles for crab waist Luminosity increase: factor ~ 3; Ldt 1 pb-1/hour

22

KLOE Upgrade


Minimal detector upgrade for first KLOE-2 run (≈5 fb-1 in 1 year):

taggers to detect momentum of leptons in e+e→e+e→e+eX

Inner Tracker:4 layers of cylindrical triple GEM

Q-CALT/C-CALT: Increase acceptance for ’s from IP (21°→10°)

Conclusions

High statistic samples of light mesons produced @KLOE allowed to perform precision measurement and to look for very rare decays

Analysis on full KLOE data set:→ U,→[PLB706 (2012) 251-255]→ [Preliminary in arXiv: 1107.5733 hep-ex]→ → [arXiv: 1107.3782 hep-ex]

e+e- taggers in KLOE-2

New data taking@KLOE-2 in 2012: not stable running yet


SPARE


e+ e- , with +-0

BR(e+e-)=1.15 10-4 : produced events 106 e+e-

PLB706 (2012) 251-255


peak

Ks KL

e+ e- , with +-0

• We have 14000 candidates: e+e- with + - 0

• Very small residual contamination from • MC Mee shape from VMD with FF slope from SND (213 events) [PLB504

(2001) 275]

Background extracted directly from dataC. Di Donato - Rencontres de Moriond QCD 27

PLB706 (2012) 251-255

2011/06/14 28

Physics:

Ne e e e X XX

Weizsäcker-Williams approx, |q2|

<< W2

Tagger is essential to reduce bckg from and to close kinematics KLOE-2

Lint = 1 fb

Xeeee

Fusion


eeee 0

sE

psEMsM

T

LTmiss

222 2

@KLOE without tagger

Fusion


eeee 000


Fusion00 eeee

Fusion:

2011/06/14 32

00 eeee

33

Fusion: 00 eeeePRELIMINARY

@KLOE without tagger

KSKL

ωπ0

f0γ

• 240 pb-1 @ s = 1 GeV• 8090 events after selections• Bkg normalized using x-sections

CAMILLA DI DONATO SEZ. INFN NAPOLI ON BEHALF OF KLOE AND KLOE-2 COLLABORATIONS Hadron Physics at...

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