Spring JPS Meeting at Sendai Single spin asymmetry

Spring JPS Meeting at Sendai Single spin asymmetry of decay muons in transversely polarized p+p collisions at sqrt(s)=200 Ge. V 1. 2. 3. 4. 5. 6. 1 はじめに 偏極p+pビーム PHENIX ミューオンアーム p/K崩壊ミューオンサンプ ル スピン非対称度の解析 まとめ 3/29/2003 The title has been changed from “Single muon production in transversely polarized p+p collisions at sqrt(s)=200 Ge. V” 小林 秀幸 (理研BNL研究センター) 他 PHENIX 共同実験 Hideyuki Kobayashi

RHIC 偏極 p+p ビーム RHIC p. C Polarimeters PHOBOS Yellow beam Blue beam +-+- ++-- Absolute Polarimeter (H jet) RHIC PHENIX STAR Siberian Snakes 60 or 120 bunches Spin Rotators Partial Siberian Snake LINAC Pol. Proton Source 75% polarization BRAHMS & PP 2 PP BOOSTER AGS Internal Polarimeter Rf Dipoles 200 Me. V Polarimeter 3 Hideyuki Kobayashi Illustrated by Thomas Roser 3/29/2003

PHENIX ミューオンアーム Run 2 (2001 -2002) Hadron Absorbers ~10λint Beam-Beam Counter (BBC) - Trigger, Vertex Δz~2 [cm] Muon Identifier (Mu. Id) - 5 layers - Hadron rejection ~ - Trigger threshold p=2 [Ge. V/c] - Rough tracking (road) 4 Muon Tracker (Mu. Tr) - 3 stations - Cathode strip readout - Radial field magnet -Δp/p~3%@3~10 [Ge. V/c] Hideyuki Kobayashi 3/29/2003

ルミノシティー非対称度の fill (時間) 依存性 Backward (Blue) Forward (Yellow) 5% LR Red points m+ Blue points m- 10 Fill 依存性あり。 l Yellow ビームと Blue ビームによ る違いあり。 l Charge による違 い小さい。 l L/R と T/B による 違い小さい。 -5~15% TB 5% l -5~15% Hideyuki Kobayashi 3/29/2003

Backup slides follows 13 3/29/2003 Hideyuki Kobayashi

J/y by muon arm in Run 2 • Significant enhancement of unlike-sign pair in the J/ mass region • Peak (3156 74 Me. V/c 2) is consistent with J/ mass • Mass width (257 75 Me. V/c 2) is consistent with expectation further improvement is expected • NJ/ = 36 in 2. 5<mass<3. 7 Ge. V/c assuming same count of unlike and like-sign pairs from background (confirmed with simulation) • Systematic error on the count ~10 % by changing mass cut 14 Hideyuki Kobayashi 3/29/2003

Asymmetries from RHIC sqrt(s)=200 Ge. V Kinematical Coverage PT XF 0. 2 0. 4 0. 6 0. 8 +10 ~ +20% PHENIX MUON STAR TPC PHENIX CENTRAL Charged ~0. 5% STAR FNAL FPD E 704 STARPHENIX BBC pp 2 pp 0 o CAL 0 Okada’s talk 1 2 3 Tanida’s talk p 0 (at high XF ) 4 5 Rapidity FNAL E 704 sqrt(s)=20 Ge. V p+, p - (at high XF ) +10 ~ +30% Neutron -10% g ~0% p 0 <3% Fukao’s talk This talk Muon Arm covers very small XF ~0. 03 15 Hideyuki Kobayashi 3/29/2003

Z vertex Dependence Normalized Muon Biased Z vertex Muon Track Z vertex Accepted by South Muon Arm z [cm] Minimum Bias Z vertex z [cm] m p Beam Absorber 16 Absorber p/K decay m z [cm] direct m, punch throw hadron, … p/K decay m dominates >80% Hideyuki Kobayashi 3/29/2003

ディテクター非対称度の fill (時間) 依存性 Backward (Blue) LR Forward (Yellow) Red points m+ -30% Blue points m- -50% Definition of L/R is opposite between backward and forward. 50% 30% TB 17 30% 30% Hideyuki Kobayashi 3/29/2003