Quarks and Compact Stars (QCS)
Oct. 20-22, 2014, KIAA at Peking University, Beijing - P. R. China


Talk

Fluctuations in dual chiral density wave

Tong-Gyu Lee

Japan Atomic Energy Agency, and Kochi University

Abstract: The inhomogeneous chiral (ICh) phase has recently been in the limelight in the phase structure of QCD at finite densities. The emergence of this phase is predicted not only in chiral effective models, e.g., Nambu--Jona-Lasinio scheme or linear sigma model with quarks, but in nonperturbative treatments using large-$N_c$ limit or Schwinger-Dyson approach as well. Thus, the ICh phase may exist in the QCD world, and also might be realized in the compact star interiors, like the nuclear pasta phase with spatial inhomogeneities. Within the model-independent analysis, such as Ginzburg-Landau expansion, it is suggested that QCD critical endpoint might coincide with Lifshitz poiont at which a disordered phase, a uniform ordered phase, and a nonuniform ordered phase meet each other. Hence, the chiral critical behaviors also could be modified by the presence of ICh phase. So far many studies have been performed on the possible ground states for the ICh phase. However, fluctuations and stabilities in such phases are still poorly understood, whereas various order-parameters for the chiral nonuniform condensate have been addressed. In this talk, we first focus on the low-energy excitation modes on the ground state of the ICh phase, taking the dual chiral density wave (DCDW) with one-dimensional modulation as a example of the ICh condensate. Here, we show that the unique symmetry is realized and the properties for would-be Nambu-Goldsotne modes are exotic in the DCDW phase. Also, we discuss the stability of the phase against fluctuations of the order-parameter at zero and finite temperature.