Speaker
Description
Title:
Tracking the Baryon Number with Heavy Ion Collisions
Abstract:
The baryon number is a fundamental quantity in quantum chromodynamics. The conventional quark model assigns baryon number equally to the three valence quarks, while an alternative hypothesis proposed in the 1970s suggests that it may instead be carried by a Y-shaped gluonic topological configuration—the "baryon junction"—that connects them. Neither picture has been confirmed or ruled out experimentally. The STAR Collaboration has addressed this question through precision measurements of baryon stopping and its correlation with charge stopping in relativistic heavy-ion collisions at RHIC. The measured baryon stopping is found to be significantly stronger than valence quark stopping scenario, and stronger than what charge stopping would imply. These results are inconsistent with the valence-quark picture but naturally explained by the baryon-junction hypothesis. This seminar will cover the physics motivation, experimental measurements and physics implications of this study.
Brief introduction about the speaker:
Zebo Tang is a professor at the School of Physical Sciences, University of Science and Technology of China (USTC). He received his B.S. (2004) and Ph.D. (2009) from USTC and has been on the faculty since graduation. His research focuses on experimental high-energy nuclear physics. He is a long-standing member of the RHIC-STAR Collaboration and currently serves as one of its Deputy Spokespersons.
