Download - DY at STAR for decadal plan (run15-20)
DY at STARfor decadal plan (run15-20)
Akio Ogawa
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DY
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DY : ~7 x 10-5 mb @ 500GeV
Hadronic : ~30mb 106
Hadron & photon backgroundsCharm & bottom backgrounds
Need >100 Billion hadronic events to simulate backgrounds
PHENIX Muon ArmEta = 1-2
DY Charm Bottom
http://spin.riken.bnl.gov/rsc/write-up/dy_final.pdf
STAR forward detectors
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≈ 6 Lint spaghetti calorimeter10cm x 10cm x 120 cm “cells”
DX shell R ~ 60cm
Proposed FHC(for jet & lambda)
FMSIn open position
x~50cm from beam
No space for FHC near beamNo space in front of FMS neither
FTPC (to be removed next year)
DY signal
Everything >2
FMS closed(FHC cannot be placed dueTo DX magnet)
FMS open (x=50cm)+ FHC (x=60cm)
pythia6.222, p+p @ sqrts=500DY process, 4M events/6.7E-05mb ~ 60/pbe+/e- energy>10GeV & >2xF>0.1 (25GeV)4GeV < invariant mass < 10GeV
Inv Mass E pT
14799 events
6512 events
1436 events(1/5 from closed)
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(direct) b backgroundpythia6.222, p+p @ sqrts=500DY process, 4M events / 6.7E-05mb ~ 60/pbB production, 300M events / 5.2E-03mb ~ 58/pb(Fragmentation b need 180B events / 30mb ~ 60/pb)
FMS closed : small at high xF & high eta & mostly unlike sign
Inv Mass E pT
DYDirect B Direct B unlikeDirect B like
FMS closed
e+/e- energy>10GeV & >2xF>0.1 (25GeV)4GeV < invariant mass < 10GeV
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(direct) b background
Everything >2 FMS closedFMS open (x=50cm)+ FHC (x=60cm)
Electron/position radius from beam at FMS
DYDirect B
e+/e- energy>10GeV & >2xF>0.1 (25GeV)4GeV < invariant mass < 10GeV
pythia6.222, p+p @ sqrts=500DY process, 4M events / 6.7E-05mb ~ 60/pbB production, 300M events / 5.2E-03mb ~ 58/pb(Fragmentation b need 180B events / 30mb ~ 60/pb)
FMS closed : small at high xF & high eta & mostly unlike sign FMS opened + FHC : significant @ low xF & small eta(even smaller eta/phenix muon arm : b > DY) 6
High xF DY @ STAR needs• High > 4 coverage• Additional e/Hadron separation
– hadron suppression > 1/1000 per hadron
• Additional e/Gamma separation (incl gamma->e+e-) – gamma suppression > 1/1000 per gamma
• Forward tracking for charge like/unlike sign (?)• Significant trigger upgrades
– FMS with localized hadron & neutral veto
• Extension of west platform
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DY @ STAR for decadal planrun15-20
1) FFGT + Pre-Showers/Tracker/SMD + Shorter Ecal (PbW) + Hcal + removal of west platform
2) FFGT + Pre-showers/TRD/Tracker/SMD + FMS (fill 20cm x 20cm hole around beam pipe?) + extension of west platform
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e/Hadron separation
• Trigger & offline– FMS (rarely measure full hadron energy)– FMS + FHC veto (1/10 – 1/1000 depends on energy)
No space for ecal + hcal at eta=4 between DX & poletip holder– Pb Converter + Early-shower detector (~1/10) – Electron-ID like TRD or TR-Tracker (1/10 – 1/100)
• Offline– E(FMS)/p(tracking) Hard to measure p well at high xF with STAR magnet– FMS (or FMS-SMD) shower shape analysis (Need study)
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EM calorimeter…
• 2500 PbWO crystals
• APD readout
• 1264 lead glass
• PMT readout
hadron calorimeter…
• 1400 towers (Atlas)
wheel/spoke support for DX and hadron calorimeter
DX
Wide Angle Hall Floor
Concept for forward
EM+hadron calorimeter at
STAR
Existing west side of Wide Angle Hall
3/27/1010
HjC - STAR@BNL
H. Crawford/L. Bland
• Cherenkov – Beta(pion) @ 1GeV 0.99– Beta(pion) @ 3GeV 0.999– air 1/n 0.99970 – hydrogen 1/n 0.99986– Beta(pion) @ 10GeV 0.9999– Beta(pion) @ 30GeV 0.99999– Beta(electron) @ 1GeV 0.9999999
• Transition Radiation Detector (TRD)– ALICE http://www-alice.gsi.de/trd/transp/andronic07.pdf– AMS http://cyclo.mit.edu/~bmonreal/trd.html– HERMES http://hermes.desy.de/notes/pub/96-LIB/thiessen.96.028.ps.gz
Electron PID (hadron rejection)
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TRD
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1 layer (out of 20 layers) AMS TRDhttp://cyclo.mit.edu/~bmonreal/trd.html
HERMES TRD Performance http://hermes.desy.de/notes/pub/96-LIB/thiessen.96.028.ps.gz
Electrons/positrons emit X-raysWhich are detected in Xe/CO2 gasdetector, in addition to normal ionization
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e/Gamma separation • Trigger & offline
– Neutral veto in Pre-Shower detector (~1/100)– Gamma->e+e- conversion in beam pipe
• Pre-shower with 2MIP/e+e- conversion pair veto (~1/100?)– Gamma->e+e- conversion in preshower (~1/2)
• Small radiation length in preshower (or 1st tracking station) desired
– Thin Pre-Shower detector with good resolution to do 0mip - 1mip - 2mip separation
• Offline – Reconstructing pi0 (and eta) and removing them in FMS ( ~ 1/10)– Tracking to resolve single electron to pair (? Need study)
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Red foils: H/V traces
Blue foils: Diag traces
GEM based Pre-shower & Early-shower detectors
Pre-shower 0.3mm – 0.9mm pitch 55k channels
~2RL Pb Converter
Early-shower 2mm -3mm pitch 11k channel
Total 66k channels
Carl Gagliardi
Charge like/unlike sign
• Charge like/unlike sign separation needed?• If so, STAR solenoid enough?• Or need forward dipole magnet? • Tracking
– FGT with small R + a couple more rings ?– Another tracker at FMS (pre-shower or SMD) ?
• Momentum resolution for E/p ?• c/b tag ?
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STAR Magnetic Field
• Radial and Azimuthal fields impart impulses in the Φ direction and partially cancel
Chris QM09 talk : http://drupal.star.bnl.gov/STAR/files/QM2009_Perkins_v5_0.ppt
€
Δϕ =c( Bz∫ dr − Br∫ dz)
Pr
≈c
Pr
(0.5T⋅Pr
Pz
4m −3.5
0.4
Pr
Pz
0.1T⋅1m)
≈0.6 − 0.26[radian]
Pz[GeV ]≈
0.34[radian]
Pz[GeV ]17
Run8 FMS-FTPC (Jim Drachenberg)http://www.star.bnl.gov/protected/spin/drach/Run8FMS/FMS-FTPC_correlation/
ΔΦ = 0.1 Δz/pz (Δz=2.5m) = 0.25 radian / GeV For 10GeV at y=0 @ FMSΔy @ x=20cm = 0.5cmΔy @ x=40cm = 1.0cmΔy @ x=80cm = 2.0cm
For 50GeV at y=0 @ FMS Δy @ x=20cm = 0.1cmΔy @ x=40cm = 0.2cmΔy @ x=80cm = 0.4cm
FTPC+FMS have done chargeseparation with STAR magnet at 2.8<<3.8 E ~ 10GeV
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(FTPC)
FGT extension?
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J. Balewski/MIT
Dipole Analysis Magnet ConceptPresent RHIC Interaction Regions
Conceptual Plan to Allow DXA
• reduce field strengths in D0,DX
• move DX towards IP
Forward DY Interaction Region
if charge sign required
• DXA used for beams and for DY daughters
3/27/1021
HjC - STAR@BNL
H. Crawford/L. Bland
DY @ STAR for decadal planrun15-20
1) FFGT + Pre-Showers/Tracker/SMD + Shorter Ecal (PbW) + Hcal + removal of west platfrom ~ 10 M$ ??
2) FFGT + Pre-showers/TRD/Tracker/SMD + FMS (fill 20cm x 20cm hole around beam pipe?) + extension of west platform ~ 5M$ ??
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backup
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Some documents
• Updated FHC proposalhttp://hena.lbl.gov/FMS/docs/hcal_proposal_update_091001.pdf
• Hank's FHC talk at STAR upgrade meetinghttp://drupal.star.bnl.gov/STAR/system/files/FHC_091217.pdf
• DY paper (2007)http://spin.riken.bnl.gov/rsc/write-up/dy_final.pdf
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Simple QEDexample:
DIS: attractive Drell-Yan: repulsiveSame in QCD:
As a result:
Attractive vs Repulsive Sivers EffectsUnique Prediction of Gauge Theory !
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Siv
ers
Am
plitu
de
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HERMES Sivers Results RHIC II Drell Yan Projections
Markus DiefenthalerDIS WorkshopMűnchen, April 2007
DOE HP13 milestone“Test unique QCD predictions for relations between single-transverse spin phenomena
in p+p scattering and those observed in deep-inelastic lepton scattering” with an estimated completion of 2015”
Attractive vs Repulsive Sivers Effects
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