报告介绍: |
摘要:
Nuclei at very high energy, characterized by a saturation scale, can be described by an effective theory of Quantum Chromodynamics (QCD) called Color Glass Condensates. The earliest phase of the collision of two nuclei is modeled as the collision of two sheets of color glass. The classical field resulting from the collision then decays and equilibrates to a plasma of quarks and gluons. Using a recursive solution of the Yang-Mills equations, we calculate analytic expressions for the gluon field and energy-momentum tensor created in ultra-relativistic heavy ion collisions at small times τ. We generalize the existing calculations to go beyond the limit of large, homogeneous nuclei. This allows us to calculate radial and elliptic flow of gluon fields. The resulting transverse and longitudinal structure of the Poynting vector field has a rich phenomenology. We found a rapidity-odd transverse flow that tilts the fireball for non-central collisions, and it implies a characteristic flow pattern for collisions of non-symmetric systems A+B. This rapidity-odd term leads to angular momentum of the glued field shortly after the collision (up to times ∼1/Qs, where Qs is the saturation scale). We then discuss the transfer of angular momentum in high energy nuclear collisions from the colliding nuclei to the region around midrapidity. We also discuss in detail the process of matching classical Yang-Mills results to fluid dynamics.
报告人简介:
Dr. Guangyao Chen is an Assistant Professor of Physics at Jacksonville University. Dr. Chen received his bachelor's and master's degrees in Physics from Wuhan University. He conducted research on heavy-ion collisions at Texas A&M University, where he obtained his Ph.D. in 2013. After receiving his doctorate, he was a postdoctoral research associates at Iowa State University, where he focused on researching light-front quantization, especially the mechanisms of diffractive vector meson production using wave functions generated by Basis Light-Front Quantization, as well as the time-evolution of Basis Light-Front Quantization. |