Nuclear and Particle Physics Colloquium

(核与粒子物理学术报告会)

Place:Room 513 Small, Main Building, Beihang University

Time:10:30-12:00, March22, 2019

Title:Bottomoniummeasurementsat the CMS experimentandsearchfornewphysicsin the Y(1S)μ⁺μ⁻channel

Speaker:Prof.ZhenHu,Tsinghua University

Abstract：

In the first part of my talk, I will give a brief overview of the bottomonium measurements from the CMS experiment at the Large Hadron Collider. These include precision measurements of Upsilon cross sections and polarizations in proton collisions and in collisions involving heavy ions, shedding light on hadroproduction mechanisms, and the observation of quarkonium sequential suppression, a notable indication of quark gluon plasma formation. The observation of the production of bottomonium pairs will also be reported along with searches for new states. In the second part of the talk, we will 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 is developed 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 from Purdue University in 2014. He was a postdoctoral research associate at Fermilab before joining the experimental high energy physics group at Tsinghua University in 2018. For most of his career Dr. Hu has studied the fundamental particles and has been in pursuit of new physics that can provide a more complete description of particle physics. Dr. Hu joined the Compact Muon Solenoid (CMS) experiment at CERN in 2007. Over the past 10 years, his research covered 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 and the first observation of Upsilon Suppression in the heavy ion data -- a smoking-gun signature of a new state called the Quark Gluon Plasma. He is now the Level 2 convener of the CMS PPD group.