Time & Place: Dec. 18, Wednesday, 10: 00 am, Room 9409

Speaker: Dr. Ming Li, University of Connecticut, USA（美国康涅狄格大学）

Title: JIMWLK Equation From Quantum-Classical Correspondence

Abstract:
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In Color Glass Condensate effective theory for high energy quantum
chromodynamics, hard gluons whose longitudinal momenta larger than
some cutoff scale are characterized by color currents. When
calculating observables, averaging over hard gluonic degrees of
freedom is implemented by integrating over classical color currents
with some probabilistic weight functional. The evolution of the weight
functional with the cutoff scale follows the Jalilian-Marian, Iancu,
McLerran, Weigert, Leonidov, Kovner (JIMWLK) equation for dense color
currents in the leading logarithmic approximation. In this talk, I
will first give a pedagogical review of the two different ways of
deriving the JIMWLK equation. I then talk about a different
perspective of obtaining the JIMWLK equation from the density matrix
approach of open quantum systems. We introduce an effective density
matrix for hard gluons and show its evolution with rapidity has the
form of Lindblad equation. The JIMWLK equation is reproduced by
formulating the Lindblad equation in the non-Abelian phase space
spanned by the classical color currents using Weyl's quantum-classical
correspondence rules. The weight functional naturally relates to the
density matrix through the Wigner transformation.