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Title: Enhancement of quark number susceptibility with an alternative pattern of chiral symmetry breaking in dense matter

Journal Article · · Physical Review. D, Particles Fields
;  [1];  [2]
  1. Department of Physics, Nagoya University, Nagoya, 464-8602 (Japan)
  2. Physik-Department, Technische Universitaet Muenchen, D-85747 Garching (Germany)

We explore general features of thermodynamic quantities and hadron mass spectra in a possible phase where chiral SU(2){sub L}xSU(2){sub R} symmetry is spontaneously broken while its center Z{sub 2} symmetry remains unbroken. In this phase, chiral symmetry breaking is driven by a quartic quark condensate although a bilinear quark condensate vanishes. A Ginzburg-Landau free energy leads to a new tricritical point between the Z{sub 2} broken and unbroken phases. Furthermore, a critical point can appear even in the chiral limit where explicit breaking is turned off, instead of a tricritical point at which restoration of chiral and its center symmetries takes place simultaneously. The net quark number density exhibits an abrupt change near the restoration of the center symmetry rather than that of the chiral symmetry. Hadron masses in possible phases are also studied in a linear sigma model. We show that, in the Z{sub 2} symmetric phase, the qq-type scalar meson with zero isospin I=0 splits from the qq-type pseudoscalar meson with I=1.

OSTI ID:
21409011
Journal Information:
Physical Review. D, Particles Fields, Vol. 81, Issue 1; Other Information: DOI: 10.1103/PhysRevD.81.016009; (c) 2010 The American Physical Society; ISSN 0556-2821
Country of Publication:
United States
Language:
English