114 citations · 924 across the 29 of their papers we have counts for
25 papers · 1 filter
Confinement and Z_3 symmetry in three-flavor QCD
Hiroaki Kouno, Takahiro Makiyama, Takahiro Sasaki +2
We investigate the confinement mechanism in three-flavor QCD with imaginary isospin chemical potentials , using the Polyakov-loop extended Nambu--Jona-L…
A simple model with Z_N symmetry
Masanobu Yahiro, Hiroaki Kouno, Yuji Sakai +2
We propose a simple model with the Z_N symmetry in order to answer whether the symmetry is a good concept in QCD with light quark mass. The model is constructed by imposing the fla…
Model approach to the sign problem on lattice QCD with theta vacuum
Takahiro Sasaki, Junichi Takahashi, Yuji Sakai +2
We propose a practical way of circumventing the sign problem in lattice QCD simulations with a theta-vacuum term. This method is the reweighting method for the QCD Lagrangian after…
The quarkynic phase and the Z_{Nc} symmetry
Yuji Sakai, Hiroaki Kouno, Takahiro Sasaki +1
We investigate the interplay between the Z_{Nc} symmetry and the emergence of the quarkyonic phase, adding the flavor-dependent complex chemical potentials μ_f=μ+iTθ_f with (θ_f)=(…
A QCD-like theory with the ZNc symmetry
Hiroaki Kouno, Yuji Sakai, Takahiro Makiyama +3
We propose a QCD-like theory with the ZNc symmetry. The flavor-dependent twisted boundary condition (TBC) is imposed on Nc degenerate flavor quarksin the SU(Nc) gauge theory. The Q…
Theta vacuum and entanglement interaction in the three-flavor Polyakov-loop extended Nambu-Jona-Lasinio model
Takahiro Sasaki, Junichi Takahashi, Yuji Sakai +2
We investigate theta-vacuum effects on the QCD phase diagram for the realistic 2+1 flavor system, using the three-flavor Polyakov-extended Nambu-Jona-Lasinio (PNJL) model and the e…
Spontaneous parity and charge-conjugation violations at real isospin and imaginary baryon chemical potentials
Hiroaki Kouno, Mizuho Kishikawa, Takahiro Sasaki +2
The phase structure of two-flavor QCD is investigated at real isospin and imaginary quark chemical potentials by using the Polyakov-loop extended Nambu--Jona-Lasinio model. In the…
Quark-mass dependence of the three-flavor QCD phase diagram at zero and imaginary chemical potential: Model prediction
Takahiro Sasaki, Yuji Sakai, Hiroaki Kouno +1
We draw the three-flavor phase diagram as a function of light- and strange-quark masses for both zero and imaginary quark-number chemical potential, using the Polyakov-loop extende…
Theta vacuum effects on QCD phase diagram
Yuji Sakai, Hiroaki Kouno, Takahiro Sasaki +1
Theta vacuum effects on the QCD phase structure in the μ-T plane are studied by using the Polyakov-loop extended Nambu-Jona-Lasinio model and its extension, where μis the quark che…
Equation of state in the PNJL model with the entanglement interaction
Yuji Sakai, Takahiro Sasaki, Hiroaki Kouno +1
The equation of state and the phase diagram in two-flavor QCD are investigated by the Polyakov-loop extended Nambu--Jona-Lasinio (PNJL) model with an entanglement vertex between th…
Violations of parity and charge conjugation in the theta vacuum with imaginary chemical potential
Hiroaki Kouno, Yuji Sakai, Takahiro Sasaki +2
Charge conjugation (C) and Parity (P) are exact symmetries at theta =pi and Theta = mu/(iT)=pi, where theta is the parameter of the so-called theta-vacuum, mu is the imaginary quar…
Comparison between LQCD and PNJL model at finite chemical potentials
Yuji Sakai, Takahiro Sasaki, Hiroaki Kouno +1
Lattice QCD has the sign problem at real quark chemical potential. There are some regions with no sign problem; one is the imaginary quark chemical potential region and the others…
C and P violations in the PNJL model
Hiroaki Kouno, Yuji Sakai, Takahiro Sasaki +2
Using the PNJL model, we investigate C and P violations when theta =pi and Theta =mu/(iT)=π/3, where T, theta and mu are the temperature, the parameter of theta-vacuum and the quar…
Entanglement between deconfinement transition and chiral symmetry restoration
Yuji Sakai, Takahiro Sasaki, Hiroaki Kouno +1
We extend the Polyakov-loop extended Nambu-Jona-Lasinio (PNJL) model by introducing an effective four-quark vertex depending on Polyakov loop. The effective vertex generates entang…
Average phase factor in the PNJL model
Yuji Sakai, Takahiro Sasaki, Hiroaki Kouno +1
The average phase factor of the QCD determinant is evaluated at finite quark chemical potential (μ_q) with the two-flavor version of the Polyakov-loop extended Nambu-Jona-Lasinio (…
QCD phase diagram at finite baryon and isospin chemical potentials
Takahiro Sasaki, Yuji Sakai, Hiroaki Kouno +1
The phase structure of two-flavor QCD is explored for thermal systems with finite baryon- and isospin-chemical potentials, mu_B and mu_{iso}, by using the Polyakov-loop extended Na…
QCD phase diagram at imaginary baryon and isospin chemical potentials
Yuji Sakai, Hiroaki Kouno, Masanobu Yahiro
We explore the phase diagram of two-flavor QCD at imaginary values of baryon and isospin chemical potentials analyzing the thermodynamic potential of QCD analytically and that of t…
Roberge-Weiss phase transition and its endpoint
Hiroaki Kouno, Yuji Sakai, Kouji Kashiwa +1
The Roberge-Weiss (RW) phase transition in the imaginary chemical potential region is analyzed by the Polyakov-loop extended Nambu--Jona-Lasinio (PNJL) model. In the RW phase trans…
Determination of QCD phase diagram from the imaginary chemical potential region
Yuji Sakai, Kouji Kashiwa, Hiroaki Kouno +2
We test the reliability of the the Polyakov-loop extended Nambu-Jona-Lasinio (PNJL) model, comparing the model result with the lattice data at nonzero imaginary chemical potential.…
Meson mass at real and imaginary chemical potentials
Kouji Kashiwa, Masayuki Matsuzaki, Hiroaki Kouno +2
The chemical-potential dependence of pi and sigma meson masses is analyzed at both real and imaginary chemical potentials, and , by using the Polyakov-…
Roberge-Weiss phase transitions and extended Z3 symmetry
H. Kouno, Y. Sakai, K. Kashiwa +2
Using the Polyakov extended Nambu-Jona-Lasinio (PNJL) model with imaginary chemical potential, the relation between the Roberge-Weiss (RW) phase transition and the extended Z3 symm…
Vector-type four-quark interaction and its impact on QCD phase structure
Yuji Sakai, Kouji Kashiwa, Hiroaki Kouno +2
Effects of the vector-type four-quark interaction on QCD phase structure are investigated in the imaginary chemical potential region, by using the Polyakov-loop extended Nambu-Jona…
Correlations among discontinuities in QCD phase diagram
Kouji Kashiwa, Yuji Sakai, Hiroaki Kouno +2
We show, in general, that when a discontinuity of either zeroth-order or first-order takes place in an order parameter such as the chiral condensate, discontinuities of the same or…
Phase diagram in the imaginary chemical potential region and extended Z3 symmetry
Yuji Sakai, Kouji Kashiwa, Hiroaki Kouno +1
Phase transitions in the imaginary chemical potential region are studied by the Polyakov loop extended Nambu-Jona-Lasinio (PNJL) model that possesses the extended Z3 symmetry. The…