Speaker
Mr
Masahiro Ishii
(Kyushu University)
Description
We determine temperature (T) dependence of U_A (1) restoration from meson screening masses calculated with 2+1 flavor lattice QCD, using PNJL model with entanglement vertex. The entanglement PNJL (EPNJL) model exhibits the U_A (1) anomaly through the Kobayashi- Maskawa- ’t Hooft (KMT) interaction. T dependence of KMT interaction strength is then determined from the difference between pion and a0 meson screening masses. The strength is strongly suppressed around the pseudocritical temperature of chiral transition. This suppression is much stronger than that predicted by instanton liquid model.
Using this T-dependent KMT interaction, we draw the Columbia plot near the physical point. In the light-quark chiral-limit with the strange quark mass (m_s) fixed at the physical value, the chiral transition becomes the second order. A tricritical point appears when m_s is slightly below the physical value. Finally, we calculate T dependence of other meson screening masses with the EPNJL model and compare the model results with lattice QCD ones to check the validity of the present model.
Primary author
Mr
Masahiro Ishii
(Kyushu University)
Co-authors
Prof.
Hiroaki Kouno
(Saga University)
Mr
Junichi Takahashi
(Kyushu University)
Prof.
Masanobu Yahiro
(Kyushu University)
