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Arnaud Lucotte ISN-Grenoble J/ e + e - selection at D RunII Arnaud Lucotte (ISN Grenoble) Introduction A. J/ production at the TeVatron 1. Prompt production:

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Presentation on theme: "Arnaud Lucotte ISN-Grenoble J/ e + e - selection at D RunII Arnaud Lucotte (ISN Grenoble) Introduction A. J/ production at the TeVatron 1. Prompt production:"— Presentation transcript:

1 Arnaud Lucotte ISN-Grenoble J/ e + e - selection at D RunII Arnaud Lucotte (ISN Grenoble) Introduction A. J/ production at the TeVatron 1. Prompt production: direct and c 2. Production from b decays 3. Cross-sections at fnal B. J/ detection with the upgrade D 1. Upgrade detectors for J/Psi 2. Trigger Constraints at Run II 3. Trigger Architecture C. Triggering on J/ e + e - at D 1. L1 and L2 Triggers 2. Reconstruction 3. J/ e + e - yields Conclusion

2 Arnaud Lucotte ISN-Grenoble Introduction: J/Psi at Run II B Physics: bbar 50 b 32 cm 2 s -1 ) w/ bbar < 1/1000 dj Violation CP dans le systeme B d 0 : B S Oscillations B s 0 D S (D S ) 2000 evts attendus (~70 fs time resolution) Other b-topics: Rare b Decays Spectroscopy B C Detector Calibration: Calibration: CC, EC-EC, EC-CC using Z ee,, ee

3 Arnaud Lucotte ISN-Grenoble J/ Production at TeVatron 1. Prompt Production of J/ s (a) direct production Color Singlet Model (CSM) (see graphs) built to describe ISR data predicts direct processus is dominant factor 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

4 Arnaud Lucotte ISN-Grenoble J/ Production at TeVatron (a) Quarkonium Production (CSM) 1 S 0 3 P j 1 S 0 3 P 0,2 1 S 0 3 P j 1 S 0 3 S 1 3 P j 1 S 0 3 P j g g g g g g g g g g g g g g g q q q q g O( s 3 )

5 Arnaud Lucotte ISN-Grenoble J/ Production at TeVatron 2. b-decay production (a) b-decays contribution CDF+D0: depends on p T d p vs p T, 3. J/ Production Cross-section CDF central: p >5GeV, <0.6 D0 all detector: d p vs 1-30% J/ from b-decays D0 = nb D0 production ~centrale

6 Arnaud Lucotte ISN-Grenoble J/ Production at TeVatron 3. J/ signal at the TeVatron (a) Momentum: p T J/ p T B with p T B ~ M B, p T l ~ 2.5 GeV/c lepton even softer for prompt production (b) Anglular distribution: J/ more central (e+,e-) ã few degrees

7 Arnaud Lucotte ISN-Grenoble Solenoide, Detecteur de Traces Silicon Vertex, Preshowers Fibres Sci. Boucliers Chambres a derive (Mini-drift) Arrieres Scintillateurs Arrieres Scintillateur Central + Nouvelle Electronique, Trig, DAQ D Upgrade

8 Arnaud Lucotte ISN-Grenoble Constraints on a J/ e - e + Trigger Signal Characteristics: B J/ X : 0.7 w/ ~ M B C J/ X: 1.5 GeV/c Calorimeter threshold as low as: E T GeV Constraints on J/ triggering Against Dijet background: ~ cm 2 s -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...

9 Arnaud Lucotte ISN-Grenoble L2FW:Combine objects (e,, j) L1CAL L2STT Global L2 L2CFT L2PS L2Cal L1PS / L1FT L2 Muon L1 Muon Detector L1 TriggerL2 Trigger 7 MHz 8 kHz 1 kHz CAL FPS CPS CFT SMT Muon Trigger Architecture (100 s) (4.2 s) L1FW: CAL towers, tracks, Muons 128 available combinations (ORs) Calorimeter vs Preshower + tracks Calorimeter vs Tracks

10 Arnaud Lucotte ISN-Grenoble L1-Central EM Triggering Detector-specific: EM Calorimeter #tower ( = ) & E T > [2.5, 5, 7, 10] GeV Central PreShower #cluster = adjacent strips such: E strip > 2-5 MIPs Fiber Tracker # signed trajectories / bin p T [1.5-3], [3-5],[5-10], [10-] GeV/c counted in each 80 x 4.5 o sectors Global-Level (Framework): Coincidence by Quadrant: 1 tower EM + (1 CPS-cluster+Track p T /sector) L1PS L1CFT L1FW L1CAL

11 Arnaud Lucotte ISN-Grenoble L1-Forward EM Trigger EM Calorimeter EM EM Calorimeter EM tower ( = ) & E T >[2.5, 5, 7, 10] GeV Forward PreShower Forward PreShower PS cluster = adjacent strips w/ E strip > 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

12 Arnaud Lucotte ISN-Grenoble L2-Central EM Triggering EM Calorimeter EM Calorimeter - L1 calo tower as seed - Total EM cluster Energy: E T EM = E T SEED + E T 2nd_max - EM Fraction: EMF = E T EM /(E T EM +E T HAD ) - Cluster Isolation: T ISO = E T EM / (E T EM +E T HAD ) (3 3 including seed) Central Preshower: Central Preshower: - 3D cluster(u,v,x) e- tagged Fiber Tracker Fiber Tracker - convert L1 p T track p T (Look Up Table) - extrapolate to EM(3) Vertex Detector Vertex Detector - combine CFT tracks - re-fit tracks : p T,, impact parameter L2CAL L2PS L2CFT L2CTT

13 Arnaud Lucotte ISN-Grenoble Forward-EM Trigger Forward-EM Trigger Occupation dans le Preshower: Interactions/cros. = cm 2 s -1 MIP detection: T>0.3 MIP occ = 7-10% cluster detection: T > MIPs occ = % Dijet+6mbias

14 Arnaud Lucotte ISN-Grenoble Forward EM Triggering Efficiency: 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 p T ) Bkgd rejection: E T ~10 GeV: 700~Hz (CAL) vs 200 Hz (CAL+PS)

15 Arnaud Lucotte ISN-Grenoble L1 Trigger J/ e - e + Efficiency: - central 25-30% - forward 5-10% - depends on CAL thresh. E T CAL GeV Dijet background: - Rate: Hz - controled with PS/CAL Quadrant Match PS/Track sector Match(4.5 o ) Threshold E FPS, & E T CAL

16 Arnaud Lucotte ISN-Grenoble L2 Trigger J/ e - e + Efficiency: - Central 20-25% - Forward 4- 8% - depends on L1 CAL E T thresholds Dijet Background: - Rates: 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 S B = B/ B

17 Arnaud Lucotte ISN-Grenoble DAQ / Trigger for PS 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 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

18 Arnaud Lucotte ISN-Grenoble CP violation with B 0 d J/ K S Projection pour sin2 (temps integre) - efficacite reco des traces: 95% - D mix 0.47, D fond = S(S+B) ~ Tag D 2 tag ~ 0.05 sin N RECO Contraintes indirectes: Sin2 = CERN-EP/98-133

19 Arnaud Lucotte ISN-Grenoble Conclusion TeVatron is a phenomenal source of J/ s 1. main source is from prompt decays 2. most *relevant* source from b-decays 3. 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 / ee 1. detector calibration (minimize M W ) 2. B physics like CP violation


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