Meson effective mass in the isospin medium in hard-wall AdS/QCD model

TL;DR

This paper investigates how the masses of light mesons split in an isospin medium using a hard-wall AdS/QCD model, deriving effective mass formulas via holographic duality and boundary action modifications.

Contribution

It introduces a new effective mass definition for boundary mesons in the holographic model and accounts for isospin medium effects without distinguished infrared boundaries.

Findings

Derived effective mass formulas for in-medium $ ho$, $a_1$, and $\pi$ mesons.

Established a boundary action approach to unify meson boundary conditions.

Confirmed the effective mass matches pole analysis from correlation functions.

Abstract

We study a mass splitting of light vector, axial-vector and pseudoscalar mesons in isospin medium in the framework of hard-wall model. We write an effective mass definition for the interacting gauge fields and scalar field introduced in gauge field theory in the bulk of AdS space-time. Relying on holographic duality we obtain a formula for the effective mass of a boundary meson in terms of derivative operator over the extra bulk coordinate. The effective mass found in this way coincides with the one obtained from finding of poles of the two-point correlation function. In order to avoid introducing distinguished infrared boundaries in the quantisation formula for the different mesons from the same isotriplet we introduce extra action terms at this boundary, which reduces distinguished values of this boundary to the same value. Profile function solutions and effective mass expressions were found for the in-medium $\rho$, $a_1$ and $\pi$ mesons.