Arnaud Lucotte ISN-Grenoble J/ e + e - selection at D RunII Arnaud Lucotte (ISN Grenoble)...

Arnaud Lucotte ISN-GrenobleArnaud Lucotte ISN-Grenoble

J/J/ee++ee-- selection at D selection at DRunIIRunII

Arnaud Lucotte Arnaud Lucotte (ISN Grenoble)(ISN Grenoble)

Introduction

A. J/ production at the TeVatron1. Prompt production: direct and c 2. Production from b decays3. Cross-sections at fnal

B. J/ detection with the upgrade D1. Upgrade detectors for J/Psi 2. Trigger Constraints at Run II 3. Trigger Architecture

C. Triggering on J/e+e- at D1. L1 and L2 Triggers2. Reconstruction 3. J/e+e- yields

Conclusion


Introduction: J/Psi at Run IIIntroduction: J/Psi at Run II

B Physics:B Physics:

bbar 50 b (10kHz@1032cm2s-1) w/ bbar<1/1000

dj

Violation CP dans le systeme Bd0 :

BS Oscillations

Bs0 DS (DS ) 2000 evts attendus

(~70 fs time resolution) Other b-topics:

Rare b Decays

Spectroscopy BC

Detector Calibration:Detector Calibration: Calibration:

CC, EC-EC, EC-CC

using Zee, , ee


J/J/ Production at TeVatron Production at TeVatron

1. Prompt Production of J/1. Prompt Production of J/ ’s ’s(a) direct production

Color Singlet Model (CSM) (see graphs)

built to describe ISR data

predicts direct processus is dominant

factor 30-50 discrepancy vs fnal data !

(b) production via c states

c states produced by

gluon fragmentation

pp c +X

c J/

Still not enough to

explain fnal data !

(c) modified direct production Color Octet Model (COM)

brings new predictions to direct production

better agreement w/ fnal data

~24% of prompt J/ from c

CDF



(a) Quarkonium Production (CSM)

1S0 3Pj

1S0 3Pj

1S0 3P0,2

1S0 3Pj

1S0 3Pj

1S0 3S1

3Pj

1S0 3Pj

g

g

g

g

gg

g

g g

gg

g

g

g

g

q

qqq

g

O(s3)

O(s3)



2. b-decay production2. b-decay production

(a) b-decays contributionCDF+D0: depends on pT

dp vs pT ,

3. J/3. J/ Production Cross-section Production Cross-sectionCDF central:

p>5GeV,<0.6

D0 all detector:dp vs

1-30% J/ from b-decays

D0

=17.42.6 nb

D0

production ~centrale



3. J/3. J/ signal at the TeVatron signal at the TeVatron

(a) Momentum:

pTJ/pT

B with pTB ~ MB ,

pTl ~ 2.5 GeV/c

lepton even softer for prompt

production

(b) Anglular distribution: J/more central (e+,e-) ã few degrees


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DD Upgrade Upgrade


Constraints on a J/Constraints on a J/ e e--ee++ Trigger Trigger

Signal Characteristics:Signal Characteristics:

B J/ X : <pT(J/> 0.7 < pTB > w/ < pT

B > ~ MB

C J/ X: <pT(J/> 1.5 GeV/c

Calorimeter threshold as low as: ET 3.0-4.0 GeV

Constraints on J/Constraints on J/ triggering triggeringAgainst Dijet background: ~7 MHz @ 1032cm2s-1

w/ band width: ~1 kHz at L1 , ~100Hz at L2 - Needs:

L1: Combination Track + Preshower + Calorimeter AND CAL/PS coincidence by Quadrant

L2: Inv. Mass reconstruction etc...


L2FW:Combine objects (e, , j)

L2FW:Combine objects (e, , j)

L1CAL

L2STT

Global L2

L2CFT

L2PS

L2Cal

L1PS /L1FT

L2Muon

L1Muon

Detector L1 Trigger L2 Trigger

7 MHz 8 kHz 1 kHz

CAL

FPSCPS

CFT

SMT

Muon

Trigger Architecture Trigger Architecture

(100 s)(4.2s)

L1FW: CAL towers, tracks, Muons• 128 available combinations (ORs) • Calorimeter vs Preshower + tracks • Calorimeter vs Tracks

L1FW: CAL towers, tracks, Muons• 128 available combinations (ORs) • Calorimeter vs Preshower + tracks • Calorimeter vs Tracks


L1-Central EM Triggering L1-Central EM Triggering

Detector-specific:Detector-specific:

EM Calorimeter

#tower (= 0.20.2) & ET > [2.5, 5, 7,

10] GeV

Central PreShower

#cluster = adjacent strips such: Estrip > 2-

5 MIPs Fiber Tracker

# signed trajectories / bin pT [1.5-3], [3-5],[5-10],

[10-] GeV/c counted in each 80 x 4.5o sectors

Global-Level (Framework):Global-Level (Framework):Coincidence by Quadrant: 1 tower EM + (1 CPS-cluster+Track pT /sector)

L1PS

L1CFT

L1FW

L1CAL


L1-Forward EM Trigger L1-Forward EM Trigger

EM Calorimeter EM EM Calorimeter EM

tower ( = 0.20.2) & ET >[2.5, 5, 7, 10]

GeV

Forward PreShower Forward PreShower

PS cluster = adjacent strips w/ Estrip > 5-10

MIPs

electron = PS cluster (u or v) + MIP (u or v)

Global Trigger (Framework) Global Trigger (Framework) Coincidence by Quadrant

1 tour EM + 1 electron (u et v) FPS

Electron in FPS

Pb

L1CAL

L1PS

L1FW


L2-Central EM TriggeringL2-Central EM Triggering

EM Calorimeter EM Calorimeter

- L1 calo tower as “seed”

- Total EM cluster Energy:ET

EM = ETSEED + ET

2nd_max

- EM Fraction:EMF = ET

EM/(ETEM+ET

HAD)

- Cluster Isolation:TISO = ET

EM/(ETEM +ET

HAD) (33 including “seed”)

Central Preshower:Central Preshower: - 3D cluster(u,v,x) e- tagged

Fiber TrackerFiber Tracker - convert L1 pT track pT

(Look Up Table) - extrapolate to EM(3)

Vertex Detector Vertex Detector - combine CFT tracks - re-fit tracks :

pT, , impact parameter

L2CAL

L2PS

L2CFT

L2CTT


Forward-EM Trigger Forward-EM Trigger

Occupation dans le Preshower:Occupation dans le Preshower: Interactions/cros. <#> = 2.1 (Poisson) @ 2. 1032 cm2s-1

MIP detection: T>0.3 MIPocc = 7-10%

cluster detection:T > MIPsocc = 0.5-2.0%

Dijet+6mbias


Forward EM Triggering Forward EM Triggering

Efficiency: Efficiency:

Background rates (QCD dijets):Background rates (QCD dijets):Pion Rejection

20-25% de conversions de 0 ‘s avant PS (avant/arr.)

PS+CAL: facteur 2-4 (eleve pour faibles pT )

Bkgd rejection: ET ~10 GeV: 700~Hz (CAL) vs 200 Hz

(CAL+PS)


L1 Trigger J/L1 Trigger J/ e e--ee+ +

Efficiency:Efficiency:- central 25-30%- forward 5-10%

- depends on CAL thresh.ET

CAL 2.75-3.5 GeV

Dijet background:Dijet background:- Rate: 200-1000 Hz - controled with PS/CAL Quadrant Match PS/Track sector Match(4.5o) Threshold EFPS , & ET

CAL


L2 Trigger J/L2 Trigger J/ e e--ee+ +

Efficiency:Efficiency:- Central 20-25%- Forward 4- 8%- depends on L1 CAL ET thresholds

Dijet Background:Dijet Background:- Rates: 50-100 Hz: region centrale - avant/arriere - Reduced by Mass Window

EM isolation Coincidence TT vs PS- reducible: vertex information (for b-decays)

2 tracks / large impact parameter SB = B/B


DAQ / Trigger for PSDAQ / Trigger for PS

Signal Readout:Signal Readout:How is it possible to read such signal ?

Two thresholds - calibration: MIP detection (1 MIP 0.9 MeV) - cluster reconstruction (e,) 5 to 60 MIPs

Trigger and Readout: - L1: chips SIFT [0/1] (FPGA) - L2: chips SVX-II [analog] (pre-processors)

SIFT

SIFT

SVX

SVX

SIGNAL MIP

SIGNAL GERBE

Logique Trigger (FPGA’ s)

SIGNAL TRIGGER

VLPC

Scintillateur

Fibres WLS

Q

0.27 Q

0.09 Q

[5-160]fC [0-150]fC


CP violation with BCP violation with B00dd J/J/KKSS

Projection pour Projection pour sin2sin2 (temps integre) (temps integre)

- efficacite reco des traces: 95%- Dmix 0.47 , Dfond = S(S+B) ~ 0.7

- Tag D2tag ~ 0.05

sin2 13.40 NRECO

Contraintes indirectes:Contraintes indirectes:

Sin2=0.75 0.09CERN-EP/98-133


ConclusionConclusion

TeVatron is a phenomenal source of J/ ’s

1. main source is from prompt decays2. most *relevant* source from b-decays3. production models still to be tested

D0 is adapted to select J/ee 1. Detectors are adapted: - Preshowers (high dynamical range) - Calorimeter (4 thresh. sets) -Tracker (tag and sign at L1)2. Triggering is feasible provided: - Preshower-Track info at L1 - Preshower-Calorimeter Match at L1 - L2 is *not* an issue for ee (it is for )

D0 will be able to make use of /ee1. detector calibration (minimize MW )2. B physics like CP violation

Arnaud Lucotte ISN-Grenoble J/ e + e - selection at D RunII Arnaud Lucotte (ISN Grenoble)...

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