1 / 24

Oct. 10, 2008 Tsutomu Mibe (KEK) for the PHENIX collaboration

Study of polarized sea quark distributions in polarized pp collisions at sqrt(s)=500GeV with PHENIX. Oct. 10, 2008 Tsutomu Mibe (KEK) for the PHENIX collaboration. Are Sea Quarks Polarized?. A fundamental question to further break down the quark spin contents DS ~0.25

noe
Download Presentation

Oct. 10, 2008 Tsutomu Mibe (KEK) for the PHENIX collaboration

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Study of polarized sea quark distributions in polarized pp collisions at sqrt(s)=500GeV with PHENIX Oct. 10, 2008 Tsutomu Mibe (KEK) for the PHENIX collaboration

  2. Are Sea Quarks Polarized? • A fundamental question to further break down the quark spin contents DS ~0.25 • Flavor sensitive measurements required • Semi-inclusive • Weak interaction

  3. Flavor is almost fixed W+ Production in pp Collisions • Best suited for Spin-Flavor Structure Studies nm • Parity violating V-A interaction selects only left-handed quarks and right-handed antiquarks m+ W+ u d

  4. Projected Sensitivity at PHENIX (500GeV pp) m- m+ AL m- m+

  5. p (250 GeV) p (250 GeV) The PHENIX detector μ

  6. Current Muon System • Muon Tracking Chambers (MuTr) • 3 stations of Cathode strip chambers with 2 or 3 gaps • Cathode (1.0 cm pitch) • Non-stereo-strip • stereo-strip • Muon Identifier (MuID) • 80 cm of steel plate absorber (total) • 5 layers of Iarocci tubes in x and y directions • Provides LL1 trigger based on road-finding MuID MuTr St#1 St#2 St#3

  7. Trigger Rate and Rejection Design Luminosity √s = 500 GeV σ=60mb L = 1.6 x1032/cm2/s PYTHIA Total X-sec rate＝9.6 MHz DAQ LIMIT =1-2 kHz （for μ arm） W signal Required RF 10,000 BUT Need Momentum Selectivity in the LVL-1 Trigger MuID LL1 RF=200 ~ 500

  8. RPC1 RPC3 Trigger Algorithm • Momentum selectivity through online sagitta measurement • Uses MuTR 1,2,3 and new Resistive Plate Chambers (RPC) planes • Out-of-time BGs rejected by fast RPC signals. Parallel session (Xiaochun He)

  9. RPC B Upgraded read out system IR Counting House Level 1 Trigger Board Trigger Merge Reformat Amp/Discri. Data Collecting Module MuTRG MRG 5% MuTRG ADTX LV1 Trig accept 2 plane MuTr FEE 95%

  10. MuTr Front End Electronics (FEE) Existing readout New addition

  11. Amplifier-Discriminator board (MuTRG-ADTX) Analog signal from MuTr (64 ch) 6.5 V Dry air Regulators (3.3, 2.5, 1.2 V) Cooling Water Cooling Water 1.2 Gbps 9.4 MHz

  12. Installation plan in 2008 • South Arm • Station 1, 2, 3 (1/2 octant) • RPC prototype D (2x 1/2 octants) • Absorber prototype (1 octant) • North Arm • Station 1 (8 octants) • Station 2 (8 octants) • Station 3 (8 octants) St.3 St.2 St.1 Collision point St.1 St.2 St.3 RPC prototype 35 cm absorber

  13. PHENIX 2008 shutdown The PHENIX detector

  14. Production status of trigger electronics Ckecking power lines • Chassis (130 pcs) • Completed mass production • Completed quality checking Water pressure/leak test Backplane check

  15. Production status of trigger electronics • Chassis (130 pcs) • Completed mass production • Completed quality checking

  16. Existing FEE MuTRG-ADTX Pseudo MuTR Chamber Production status of trigger electronics Test bench at RIKEN • ADTX boards (220 pcs) • Completed production of 132 boards • Completed quality checking of 102 boards (RIKEN/KEK/BNL) Test bench at BNL

  17. Installation status North muon arm before installation Station 3 Station 2 Station 1 N Station 1

  18. Installation status Mounting chassis to station 1 Station 3 Station 2 Station 1 N Station 1

  19. Installation status Mounting chassis to st2 Mounting chassis to bottom of st1 St2 after chassis installation

  20. Installation status Boards slided into chassis at station 1 After all boards installed at station 1

  21. Installation status • Completed construction of infrastructure at North arm • Completed mounting all chassis. • Completed installing the ADTX boards to North station 1. N Station 1

  22. And its working! • Generated test pulse at chamber strip • Read out by ADTX board (100 triggers) • North Station 1 Octant 5 Gap 3 Plane 2 Strip 4 Test pulse signal at chamber Events Signal from chamber was recorded by new trigger system! RHIC Beam Bunch counter

  23. Data merging : ADTXMRG • Merging and reformatting strip data from ADTX boards • The first prototype • Successfully receive and reformat the data from multiple ADTX boards. • Initial communication tests with downstream modules (LL1 and DCM) has been done. • Next version will be produced by the end of this year. Strip hit data from ADTX To LL1 Strip hit data from ADTX To DCM

  24. Summary • PHENIX muon arm is being upgraded to measure the AL of W boson production in pp collisions at 500 GeV. • The muon trigger upgrade has been making steady progress as scheduled. • Installation to the North muon arm will be completed during this year’s shutdown.

More Related