Time: 10:00AM, 22nd May, Monday, 2017  

Location: Room 9727 （七楼会议室）  

Speaker: Ming Liu,  Los Alamos National Laboratory, Los Alamos, NM, U.S.A.    

Title: "Probe the QGP with Beauty Quarks in the sPHENIX Experiment at RHIC"  

Abstract: “(QGP), planned for the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) in 2022 and beyond. The goal of the sPHENIX experiment is to study the microscopic nature of the quark-gluon-plasma that is believed to have existed a few microseconds after the Big Bang, filling the entire universe at a temperature of several trillion Kelvin. Measurements at RHIC and the Large Hadron Collider (LHC) at CERN have both confirmed the existence of the QGP. The QGP created in heavy nuclei collisions at very high energy has been seen to have novel emergent properties, such as very low viscosity close to the quantum limit. Measurements of hadronic jets will reveal the internal structure of the QGP via their scattering with quasi-particles in the medium. Bottom quark jets (b-jets) and B-mesons produced in heavy ion collisions at RHIC offer a unique set of observables due to the large bottom quark mass, but need to be measured across an unexplored kinematic regime. These measurements of b-jets and B-mesons are essential to produce a complete understanding of the plasma. sPHENIX is a state-of-the-art jet detector designed to collect a suite of unique jet observables with unprecedented statistics. Reconstruction and identification of b-jets and B-mesons requires both precision tracking of charged particles close to the beam collision point and high detection efficiency. We propose to build a Monolithic-Active-Pixel-Sensor based precision vertex detector (MVTX) to ensure the sPHENIX inner tracker is capable of performing these key measurements."