【正文】 and IHEP joined STAR collaboration in 1999 for TOFp。 SINAP, USTC, Tsinghua and IMP joined STAR collaboration in Oct. 2023. ? USTC team began MRPC RD in Aug. 2023 with the supports of NSFC, STAR and other Chinese collaboration institutions. ? Joined in US/PRC Cooperative Agreement on High Energy Physics since 2023 (22nd Meeting) ? Prototype MRPC (multigap resistive plate) timeofflight detectors, produced jointly between USTC and Rice Univ. and operated successfully in STAR (20233 and 20234 RHIC runs). Physics results on identified particle spectra and on semileptonic charm decays have been published. ? Approval of RHICSTAR Physics and the Construction of Barrel STARTOF” by the National Natural Science Foundation of China (Sept 10, 2023, Budget: USD) ? Approval of the STAR TOF upgrade proposal by BNL Technical Advisory Committee and Submission of the Proposal to DOE (July 2023) ? Technical Review of proposal by DOE, planned Aug. 2023 ? Suppose DOE approval in Oct. 2023, full construction start October 2023 2023/6/2829 第 59屆東方論壇，上海 MRPC TOF Barrel RD ? RUN 20233: TOF installed in STAR ? 24 MRPC modules produced at University of Science Technology China ? 6channel frontend cards, with amplifiers and discriminators, CAMAC readout ? Run 20234: TOF installed in STAR ? 5 new modules from USTC and 5 from Tsinghua University, Tsinghua developed automated techniques for manufacturing ? 24channel frontend cards with amplifier and discriminator ? RUN 20235, TOF installed in STAR, ? 16 new modules from Tsinghua ? First time use of full onboard readout electronics: digitization of data onboard ? First use of ALICE PCIPC based DAQ 2023 2023 G. Eppley et al. 2023/6/2829 第 59屆東方論壇，上海 Completed Prototype 28 module MRPC TOF Tray installed in STAR Oct. ‘ 02 in place of existing central trigger barrel tray Neighbor CTB Tray EMC Rails FEE MRPC design developed at CERN, built in USTC/China Prototype Tray Construction at Rice University 28 MRPC Detectors。 TOF “alone” PID range: pi/k ~, (pi,k)/p ~ m2 m2 ?TOF=110ps ? k p TPC alone TOF “alone” 2023/6/2829 第 59屆東方論壇，上海 Preliminary pion spectra till high pT ?TPC: ? Pion: 0~? Kaon: ~? Proton: ~1 GeV/c ? TOF: ? Pion: ~? Kaon: ~? Proton: ~3 GeV/c ? TPC+TOF: ? Pion: ~10 GeV/c ? Kaon: ~3GeV/c ? Proton: ~5 GeV/c TPC+TOF: 2023/6/2829 第 59屆東方論壇，上海 2023/6/2829 第 59屆東方論壇，上海 Electron identification Combined with TOF， electrons can be separated from pions cleanly Electorns mixed with pions if only dE/dx of TPC is used to identify particles X. Dong, . Xu, LJ Ruan, J Wu et al Lepton decay from heavy quark 2023/6/2829 第 59屆東方論壇，上海 2023/6/2829 第 59屆東方論壇，上海 2023/6/2829 第 59屆東方論壇，上海 RAuAu and RdAu of f 0 . 0 0 . 5 1 . 0 1 . 5 2 . 0 2 . 5 3 . 0 3 . 5 4 . 00 . 40 . 81 . 21 . 62 . 0 P hi k a o n p io n P ro t o n RdAuPT ( Ge V /c2)0 .0 0 .5 1 .0 1 .5 2 .0 2 .5 3 .0 3 .5 4 .00 .00 .51 .01 .52 .02 .5ST A R Prel i m i nary RdA u RAA( 60~ 80/p p ) RAA( 05/p p ) RdAu or RAAPT (G e V/c2)? RdAu of f is closer to that of p and k than that of p ?Particle production at intermediate pT region is sorted by the particle’s type, not the mass ppinelbindA uTTppineldA uTTdA u NTdydppdT dydppNdR ??? ? /,)2/( )2/(22 ??STAR Preliminary ______________ 2023/6/2829 第 59屆東方論壇，上海 Preliminary results v2 1. the elliptic flow of Φmeson gives similar behavior of Ks but