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A N DY Status Commissioning with colliding beams (p +p at s=500 GeV). L.C.Bland, for AnDY 29 March 2011 Time Meeting, BNL. ZDC Trigger. FPGA on QT board was programmed by Chris Perkins to sum response from 3 ZDC modules, and compare the sum to a threshold.
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ANDY StatusCommissioning with colliding beams (p+p at s=500 GeV) L.C.Bland, for AnDY 29 March 2011 Time Meeting, BNL
ZDC Trigger • FPGA on QT board was programmed by Chris Perkins to sum response from 3 ZDC modules, and compare the sum to a threshold. • Threshold bits are passed through an FPGA tree (DSM boards) to allow event readout to be triggered. • Timing checks of ZDC Blue 2 phototube output and time-to-amplitude converter confirm timing (and result in a small difference between Blue and Yellow ZDC, due to use of 50-ohm splitter)
IR Separation bumps manual steering After Scripted Bump Removal Beam loss(top) and ions (bottom) IP2 Collision Script IR Separation bumps IP2 into collision • Establishing collisions at IP2 required manual steering. • There was significant beam loss until beams were in head-on collisions. • Angelika Drees developed a script to minimize manual steering, initiating collisions at IP2 in one step (many thanks!) Before Scripted Bump Removal Beam loss(top) and ions (bottom) Scripting of collision start at IP2 is in operation, and minimizes impact on IP6,IP8
~2mr crossing angle ~1.6mr crossing angle ~0mr crossing angle Integrated Luminosity Estimate to Date • Presently, no accidentals correction (found to be large for ZDC). Singles rates from BBC are now scaled, following 20110302 access. • Requires calibration of effective cross section for BBC via vernier scan. • Jet analyzing power measurement sets goal of 10 / pb for run 11. • Establishing luminosity capability in run 11 is important for Drell Yan attempt in runs 12,13 (150 / pb in each run) Many thanks to C-A for removing the crossing angle at IP2
Run11 AN(Jet) arXiv:1103.1591 jet AN measurements are required to clarify signs of quark/gluon correlators related to Sivers functions. arXiv:1011.2692v1 s=200 GeV from p+pp “new” Sivers function “old” Sivers function 200GeV Non-zero jet analyzing power essentially a prerequisite before proceeding to Drell Yan • Siver’s effect only (no collin’s effect contribution) • Need AN(Jet) measurements before DY • With ~10/pb & P=50%, AnDY run11 can measure AN(Jet)
Estimates • At present threshold for IP2 collisions (average intensity < 0.901011/bunch), integrate ~200 / nb / fill • 2 fills/day has been achieved • Consequently, 12.5 days are required to get 5 / pb • Maximum possible integrated luminosity (IP2 collisions for entire fill) would yield ~700 nb/fill • One week at 2 fills/day would provide 5 / pb • Two weeks at 2 fills/day would provide 10 / pb
Issues and Plans • Issues • Resolve a few remaining single-channel issues • We are in “production” with a jet trigger >370M jet events recorded. • In coming week… • Increase per bunch intensity for IP2 bump removal? • Reduce IP2 b* during APEX? • Complete ECal gain matching Progress made offline in last week. • Commission scaler system. Scaler readout in production. Single bit issues remain. • Commission ZDC trigger for local polarimetry. In progress.
Reminder of GoalsLong-term and run-11 • Goals of ANDY project: • Establish that large-xF low-mass dileptons from the Drell-Yan process can be discriminated from background in s=500 GeV p+p collisions • Measure the analyzing power for Drell-Yan production with sufficient statistical precision to test the theoretical prediction of a sign change for DY in relation to semi-inclusive deep inelastic scattering • Establish if robust detection of Drell-Yan dileptons at large xF and low mass requires magnetic analysis critical for future facilities at RHIC
ANDY Prioritiesfor remainder of RHIC run-11 • Run-11 goals: • Establish the impact of a third IR on RHIC performance for p+p collisions at s=500 GeV- Demonstrate luminosity at IP2, as required for Drell-Yan sample in runs 12 (without magnet),13 (with magnet). Estimate that 150 / pb gives 104 large-rapidity di-electrons with M>4 GeV/c2 for p+p at s=500 GeV. Is this possible in a 10-week run? • Demonstrate calibration of HCal • Measure analyzing power for large xF jet production. Non-zero AN required for jets if Drell-Yan production has an analyzing power. Complete the measurement of the analyzing power for jet production. A non-zero AN for jets is a requirement for Drell-Yan to have non-zero analyzing power. Recent theoretical work establishes intrinsic interest in the jet analyzing power measurement.
Schematic of detector for Run-11 • Equipment in place: • HCal is two existing 9x12 modules from E864 (NIM406,227) • ECal are two small lead-glass modules from BigCal at JLab • BBC (from PHOBOS) and ZDC • Preshower is newly constructed scintillator arrays • Goals: • Establish impact of 3IR operation on PHENIX/STAR luminosity • Calibrate HCal • relative gain via cosmic-ray m • absolute energy scale via r,L,KS… • Measure hadronic backgrounds to benchmark simulations • Measure jet analyzing power (Lint~10 / pb, P=50%)
Trigger/DAQ electronics Left/right symmetric HCal Left/right symmetric ECal Blue-facing BBC Left/right symmetric preshower Beryllium vacuum pipe IP2 in January, 2011Run-11 Staging of ANDY See http://hena.lbl.gov/IP2/Business/status/<date> for pictures of progress