Nuclearand Particle Physics Colloquium 74

(核与粒子物理学术报告会74)

Place:Room 513 Small, Main Building, BeihangUniversity

Title:Bottomoniummeasurements at the CMS experiment and search for new physics in the Y(1S)μ⁺μ⁻channel

Speaker:Prof.Zhen Hu,Tsinghua University

Abstract：

In the first part of my talk, I will give a brief overview ofthe bottomonium measurements from the CMS experiment at the Large HadronCollider. These include precision measurements of Upsilon cross sections andpolarizations in proton collisions and in collisions involving heavy ions,shedding light on hadroproduction mechanisms, and the observation of quarkoniumsequential suppression, a notable indication of quark gluon plasma formation.The observation of the production of bottomonium pairs will also be reportedalong with searches for new states. In the second part of the talk, wewill discuss a search for light resonances decaying to Y(1S)μ⁺μ⁻with CMS Run 1 and Run 2 data. A new strategy based on event-mixing isdeveloped for the high pileup Run 2 data.

About speaker:

Dr. Zhen Hu received a B.S. from Sichuan University in 2007,a M.S. from Peking University in 2010 and a Ph.D. in Particle Physics fromPurdue University in 2014. He was a postdoctoral research associate at Fermilabbefore joining the experimental high energy physics group at TsinghuaUniversity in 2018. For most of his career Dr. Hu has studied the fundamentalparticles and has been in pursuit of new physics that can provide a morecomplete description of particle physics. Dr. Hu joined the Compact MuonSolenoid (CMS) experiment at CERN in 2007. Over the past 10 years, his researchcovered a broad range of areas, from data analysis to instrument development,and he played a leading role in the measurements of the Upsilon at the CMS andthe first observation of Upsilon Suppression in the heavy ion data -- asmoking-gun signature of a new state called the Quark Gluon Plasma. He is now theLevel 2 convener of the CMS PPD group.