2025/11/18 by Li, Luyang, Mao, Shijun
#FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #Nuclear Theory (nucl-th)
paper · doi:10.48550/arxiv.2511.14150
Mass spectra and Mott transitions of neutral mesons K0, π0, η, η' at finite temperature and magnetic field are investigated in a three-flavor PNJL model. We focus on the effect of gluons, which is simulated by the Polyakov potential and the inverse magnetic catalysis (IMC) effect, which is mimicked by using a magnetic field dependent coupling constant. Mass spectra show similar structure when introducing the contribution of Polyakov potential and IMC effect. The mass of K0 meson mK0 is controlled by chiral symmetry breaking and restoration. It increases with temperature in the low temperature region, and shows a mass jump at the Mott transition. Further increasing temperature, mK0 firstly decreases and then increases with temperature. π0 meson is not only the pseudo-Goldstone boson of chiral symmetry breaking, but also influenced by the flavor mixing of π0-η-η'. The behavior of mπ0 is different from mK0 only at high temperature region, which decreases with temperature. For η and η' mesons, they are affected by both the UA(1) anomaly and the flavor mixing of π0-η-η'. The mass of η meson mη decreases with temperature in low temperature region and then shows a jump at its Mott transition. After that mη firstly decreases and later increases with temperature. η' mesons is a resonant state in vacuum and in medium, and its mass mη' continuously decreases and then increases with temperature. The mass jumps of K0, π0, η mesons are caused by the dimension reduction of the constituent quarks under external magnetic field. In the PNJL model, the Mott transition temperature of K0, π0 mesons ( η meson) decrease (increases) with magnetic field. The IMC effect leads to the lower value for meson Mott transition temperature.