Meson Spectroscopy in AdS/CFT with Flavour

TL;DR

This paper calculates the meson spectrum in a supersymmetric gauge theory using AdS/CFT duality, revealing discrete spectra, mass gaps, and Regge trajectories, with insights into meson interactions and baryons.

Contribution

It provides a detailed, closed-form computation of meson spectra in a flavored AdS/CFT setup, including large spin behavior and novel spectral features.

Findings

Discrete meson spectrum with a mass gap proportional to quark mass

Regge-like behavior for small angular momentum J

Transition to Coulombic potential behavior at large J

Abstract

We compute the meson spectrum of an N=2 super Yang-Mills theory with fundamental matter from its dual string theory on AdS_5 x S_5 with a D7-brane probe. For scalar and vector mesons with arbitrary R-charge the spectrum is computed in closed form by solving the equations for D7-brane fluctuations; for matter with non-zero mass m_q it is discrete, exhibits a mass gap of order m_q / sqrt(g_s N) and furnishes representations of SO(5) even though the manifest global symmetry of the theory is only SO(4). The spectrum of mesons with large spin J is obtained from semiclassical, rotating open strings attached to the D7-brane. It displays Regge-like behaviour for J << sqrt(g_s N), whereas for J >> sqrt(g_s N) it corresponds to that of two non-relativistic quarks bound by a Coulomb potential. Meson interactions, baryons and `giant gauge bosons' are briefly discussed.