ANDY StatusCommissioning with colliding beams (p+p at s=500 GeV)

L.C.Bland, for AnDY

12 April 2011

Time Meeting, BNL

04/21/23 2

Local PolarimetryEvent data analysis to tune parameters for scaler board

• Events that pass a ZDC trigger (Blue-facing OR Yellow-facing) are analyzed. Similar information is available on scaler board (acquiring data at 9.38 MHz), although final tuning is required.

• Uses ZDC shower maximum detector to reconstruct azimuth () for event. is spin sorted, based on 7-bit bunch counter and polarization pattern.

• N±() and N±() are combined in a cross ratio analysis and then fit by sin().

04/21/23 3

Higher Intensity for IP2 Collisions

IP2 collisions have begun <3 hours after physics ON

Minimal impact on STAR,PHENIX

Fri. 8 April

1.501011/bunch

04/21/23 404/21/23 4

Integrated Luminosity Estimate to Date

• Presently, no accidentals correction (found to be large for ZDC). All rates are now scaled on bunch-crossing scalers, following 20110330 access and subsequent timing adjustments.

• 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)

~2mr crossing angle~1.6mr crossing angle

~0mr crossing angle

Many thanks to C-A for increasing the threshold for IP2 collisions

systematically increased thresholds

for IP2 collisions

04/21/23 5

We are in “production” with a jet trigger >660M jet events recorded.

• Further increase per bunch intensity for IP2 bump removal? Present criteria couples IP2 collision start with CNI measurement move CNI measurement earlier?

• Vernier scan at IP2?

• Reduce IP2 * during APEX?

• Demonstrate reproducibility

• Complete ECal gain matching Not much progress in past week.

• Begin local polarimetry production. Scaler board and FPGA configurations in production. Final tuning required

04/21/23 5

Issues and Plans

04/21/23 604/21/23 6

Backup

04/21/23 704/21/23 7

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

04/21/23 804/21/23 8

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.

04/21/23 904/21/23 9

Run11 AN(Jet)

arXiv:1011.2692v1

200GeV

Non-zero jet analyzing power essentially a prerequisite before proceeding to Drell Yan

arXiv:1103.1591 jet AN measurements are required to clarify signs of quark/gluon correlators related to Sivers functions.

from p+p

“old” Sivers function

“new” Sivers function

s=200 GeV

• 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)

04/21/23 10

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

04/21/23 1104/21/23 11

Schematic of detector for Run-11Equipment 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

• absolute energy scale via ,KS…

• Measure hadronic backgrounds to benchmark simulations

• Measure jet analyzing power (Lint~10 / pb, P=50%)

04/21/23 1204/21/23 12

IP2 in January, 2011Run-11 Staging of ANDY

See http://hena.lbl.gov/IP2/Business/status/<date> for pictures of progress

Left/right symmetric HCal

Left/right symmetric ECal

Left/right symmetric preshower

Trigger/DAQ electronics

Blue-facing BBC

Beryllium vacuum pipe