Phase diagram in the imaginary chemical potential region and extended Z3 symmetry

Yuji Sakai, Kouji Kashiwa, Hiroaki Kouno, Masanobu Yahiro

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72 Citations (Scopus)


Phase transitions in the imaginary chemical potential region are studied by the Polyakov-loop extended Nambu-Jona-Lasinio model that possesses the extended Z3 symmetry. The extended-Z3 invariant quantities such as the partition function, the chiral condensate, and the modified Polyakov loop have the Roberge-Weiss (RW) periodicity. There appear four types of phase transitions: deconfinement, chiral, Polyakov-loop RW, and chiral RW transitions. The orders of the chiral and deconfinement transitions depend on the presence or absence of current quark mass, but those of the Polyakov-loop RW and chiral RW transitions do not. The scalar-type, eight-quark interaction newly added in the model makes the chiral transition line shift to the vicinity of the deconfinement transition line.

Original languageEnglish
Article number036001
JournalPhysical Review D - Particles, Fields, Gravitation and Cosmology
Issue number3
Publication statusPublished - Aug 4 2008

All Science Journal Classification (ASJC) codes

  • Nuclear and High Energy Physics
  • Physics and Astronomy (miscellaneous)


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