Speaker
Dr
Kenji Morita
(Kyot University)
Description
The sign problem in lattice QCD prevents us from directly evaluating
thermodynamics at real quark chemical potential since the Dirac determinant
takes complex value. At imaginary chemical potential, this quantity
becomes real thus Monte-Carlo simulation is possible.
One needs an analytic continuation to relate a quantity obtained
at imaginary chemical potential to a real one. Some characteristic
features, however, have been found also at the imaginary chemical potential
as realization of the symmetries possessed by QCD. Therefore, the imaginary
chemical potential provides us additional information on the rich phase
structure of QCD.
In this work, we investigate the phase structure of Polyakov loop-extended
chiral effective models at imaginary chemical potential with a particular
emphasis on the confinement-deconfinement transition.
First we discuss the phase transitions in the PNJL and PQM models for different
implementations of the Polyakov loop potential, within the mean field
approximation. We find a critical endpoint of the deconfinement transition
at imaginary chemical potential, of which origin is shown to nicely
illustrate interplay between the chiral transition and the deconfinement.
Second, we discuss how to characterize the deconfinement transition by
utilizing the imaginary chemical potential in analogy with the so-called
dual order parameter. Finally, we discuss the effect of the quantum
fluctuation on the determination of the phase diagram in the PQM model
by making use of the functional renormalization group approach.
Primary author
Dr
Kenji Morita
(Kyot University)
