中国物理学会高能物理分会第十一届全国会员代表大会暨学术年会

The upcoming sPHENIX experiment is the next generation of large acceptance detector at RHIC whose scientific goals center on probing the strongly interacting Quark-Gluon Plasma (QGP) with jets, heavy flavor tagged jets, and Upsilon production. Upsilon is produced by hard scattering in the early times of a relativistic heavy-ion collision, thus experiencing the entire evolution of the QGP. It has a distinct advantage over charmonium measurements as a probe of QGP. I will present an overview of the sPHENIX Upsilon measurement program with an emphasis on sPHENIX electron identification capability. In particular, the EMCal detector is an essential subsystem for Upsilon measurements via its di-electron decay. Combining EMCal with the upstream TPC track and the downstream inner HCal detectors, sPHENIX can achieve a 90% eID efficiency with ~100:1 hadron rejection. High precision measurements of Upsilon production with sufficient accuracy for clear separation of the Υ(1S, 2S, 3S) states is a key deliverable of the sPHENIX physics program. I will also describe the construction effort of the Chinese sPHENIX Consortium contribution sPHENIX EMCal blocks covering the pseudo-rapidity region of 0.8-1.1. The Chinese contribution greatly enhanced the physics capability of sPHENIX for jets and Upsilon measurements.