Regge Trajectories for Mesons in the Holographic Dual of Large-N_c QCD

TL;DR

This paper models meson Regge trajectories in large-N_c QCD using holographic duality, deriving nonlinear effects from massive quark endpoints and matching lattice results.

Contribution

It provides a string-theoretic derivation of meson trajectories with massive endpoints, capturing nonlinearities observed in lattice QCD.

Findings

Linear Regge trajectories for light quarks

Nonlinear trajectories for massive quarks

Qualitative agreement with lattice QCD results

Abstract

We discuss Regge trajectories of dynamical mesons in large-N_c QCD, using the supergravity background describing N_c D4-branes compactified on a thermal circle. The flavor degrees of freedom arise from the addition of N_f<<N_c D6 probe branes. Our work provides a string theoretical derivation, via the gauge/string correspondence, of a phenomenological model describing the meson as rotating point-like massive particles connected by a flux string. The massive endpoints induce nonlinearities for the Regge trajectory. For light quarks the Regge trajectories of mesons are essentially linear. For massive quarks our trajectories qualitatively capture the nonlinearity detected in lattice calculations.