Pion Kaon and Proton Antiproton production in AuAu

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Pion, Kaon and Proton (Anti-proton) production in Au+Au collisions at sqrt(s. NN) = 62.

Pion, Kaon and Proton (Anti-proton) production in Au+Au collisions at sqrt(s. NN) = 62. 4 Ge. V Ming Shao USTC/BNL for the STAR Collaboration 9/26/2021 Hot. Quark 2004 / Taos 1

Outline Motivation Detector & dataset Particle Identification methods Analysis results (spectra etc. ) Summary

Outline Motivation Detector & dataset Particle Identification methods Analysis results (spectra etc. ) Summary 9/26/2021 Hot. Quark 2004 / Taos 2

Motivation Study the possible in-medium effect (e. g. , gluon d. E/dx) ü Particle

Motivation Study the possible in-medium effect (e. g. , gluon d. E/dx) ü Particle composition up to intermediate p. T ü Azimuthal anisotropy and centrality dependence of PID particles at intermediate/high p. T Check the coalescence/recombination model ü species dependence of v 2, RCP etc. ü particle ratio up to intermediate p. T Require hadron identification up to intermediate p. T ! 9/26/2021 Hot. Quark 2004 / Taos nucl-th/0401001 3

Experiment Detector (STAR) TPC-tracking and d. E/dx measurement MRPC TOF (TOFr) TOFp p. VPD-collision

Experiment Detector (STAR) TPC-tracking and d. E/dx measurement MRPC TOF (TOFr) TOFp p. VPD-collision time measurement 9/26/2021 Hot. Quark 2004 / Taos 4

Dataset and Cuts RHIC run 4 (2004) 62. 4 Ge. V Au+Au data ~7.

Dataset and Cuts RHIC run 4 (2004) 62. 4 Ge. V Au+Au data ~7. 2 M minbias events (-30 cm<z_vertex<30 cm) ~2. 2 M TOFr matched events Main cuts applied in our analysis n n dca(global)<3, nfitpoints>15 -0. 5<rapidity<0 30<TOFr-ADC<400 Local TOFr hit position not exceed strip geometry bounds 9/26/2021 Hot. Quark 2004 / Taos 5

PID method ( low p. T ) TPC alone PID range: pi/k ~0. 6

PID method ( low p. T ) TPC alone PID range: pi/k ~0. 6 Ge. V/c, (pi, k)/p ~1. 0 Ge. V/c; TOF “alone” PID range: pi/k ~1. 6 Ge. V/c, (pi, k)/p ~ 3. 0 Ge. V/c m 2 9/26/2021 Hot. Quark 2004 / Taos m 2 6

PID method ( intermediate p. T ) Combine TPC (n , K, p) and

PID method ( intermediate p. T ) Combine TPC (n , K, p) and TOF (m 2) information, the PID range could be greatly extended p K 9/26/2021 yield_ = 2*yield_ (n >0), if the n is a normal Gaussian distribution Hot. Quark 2004 / Taos 7

Correction of n p. T range (Ge. V/c) m 2 0. 9 -1. 0

Correction of n p. T range (Ge. V/c) m 2 0. 9 -1. 0 -1. 2 -1. 4 -1. 6 -1. 8 -2. 0 -2. 5 n Gaussian parameters mean sigma -0. 194 -0. 200 -0. 185 -0. 186 -0. 209 -0. 256 -0. 194 0. 981 0. 970 0. 943 0. 949 0. 915 0. 916 0. 962 Choose constant n Gaussian parameters of mean=-0. 2 and sigma=0. 95, so yield_ = 2. 40*yield_ (n >0); Similarly, for p(pbar) we have mean=-0. 2 and sigma=1. 0, and yield_p = 1. 73*yield_p(n p<0) 9/26/2021 Hot. Quark 2004 / Taos 8

, K and p(pbar) yield (minbias) PRELIMINARY Minbias means (0 -80%) Efficiency corrected,

, K and p(pbar) yield (minbias) PRELIMINARY Minbias means (0 -80%) Efficiency corrected, but no background correction Statistic errors only 9/26/2021 Hot. Quark 2004 / Taos 9

yield PRELIMINARY Centrality 0 -10% 10 -20% 20 -40% 40 -80% 9/26/2021 Refmult

yield PRELIMINARY Centrality 0 -10% 10 -20% 20 -40% 40 -80% 9/26/2021 Refmult cut (>=) 313 222 102 9 Hot. Quark 2004 / Taos 10

K yield PRELIMINARY 9/26/2021 PRELIMINARY Hot. Quark 2004 / Taos 11

K yield PRELIMINARY 9/26/2021 PRELIMINARY Hot. Quark 2004 / Taos 11

p/pbar yield PRELIMINARY 9/26/2021 PRELIMINARY Hot. Quark 2004 / Taos 12

p/pbar yield PRELIMINARY 9/26/2021 PRELIMINARY Hot. Quark 2004 / Taos 12

Summary By combining TPC and TOF information, we can measure , K and p

Summary By combining TPC and TOF information, we can measure , K and p spectra in intermediate p. T range Preliminary spectra of , K and p up to p. T=5 Ge. V/c are acquired in 62 Ge. V Au+Au collisions 9/26/2021 Hot. Quark 2004 / Taos 13

Thank you ! 9/26/2021 Hot. Quark 2004 / Taos 14

Thank you ! 9/26/2021 Hot. Quark 2004 / Taos 14

anti-hadron / hadron ratio PRELIMINARY -/ +: 1. 017± 0. 002 K-/K+: 0. 835±

anti-hadron / hadron ratio PRELIMINARY -/ +: 1. 017± 0. 002 K-/K+: 0. 835± 0. 006 pbar/p: 0. 458± 0. 005 Significant baryon number excess 9/26/2021 Hot. Quark 2004 / Taos 15

Proton and Antiproton Distributions from AuAu Collisions atProton and Antiproton Distributions from AuAu Collisions at
Pion proton and antiproton transverse momentum spectra inPion proton and antiproton transverse momentum spectra in
Antiproton Production Keith Gollwitzer Antiproton Source Department AcceleratorAntiproton Production Keith Gollwitzer Antiproton Source Department Accelerator
Proton and Antiproton Production in High Energy HeavyProton and Antiproton Production in High Energy Heavy
Proton and Antiproton Production in High Energy HeavyProton and Antiproton Production in High Energy Heavy
Extra Low Energy Antiproton Ring ELENA for antiprotonExtra Low Energy Antiproton Ring ELENA for antiproton
What is an Antiproton Keith Gollwitzer Antiproton SourceWhat is an Antiproton Keith Gollwitzer Antiproton Source
Kaon and Pion Fragmentation functions and SIDIS offKaon and Pion Fragmentation functions and SIDIS off
Kaon and Pion Fragmentation functions and SIDIS offKaon and Pion Fragmentation functions and SIDIS off
Pion and Kaon Structure and the Origin ofPion and Kaon Structure and the Origin of
KAON F R P Copyright by KAON PTKAON F R P Copyright by KAON PT
Inflight neutral kaon beams for precision kaon decayInflight neutral kaon beams for precision kaon decay
Two pion production in protonnucleon and proton nuclearTwo pion production in protonnucleon and proton nuclear
Transverse Momentum Dependence of SemiInclusive Pion and KaonTransverse Momentum Dependence of SemiInclusive Pion and Kaon