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.