A numerical investigation of orientifold planar equivalence for quenched mesons

TL;DR

This study uses lattice simulations to examine meson masses in SU(N) gauge theories with fermions in various representations, testing predictions of orientifold planar equivalence at large N.

Contribution

It introduces a method to separate even and odd powers in 1/N expansions and confirms the equivalence of vector meson masses across different representations at large N.

Findings

Vector meson masses converge at large N across representations

The technique effectively isolates 1/N contributions

Results support orientifold planar equivalence predictions

Abstract

We measure on the lattice the quenched pseudoscalar and vector meson masses at a fixed value of the lattice spacing for SU(N) gauge theory with fermions in the adjoint, in the symmetric and in the antisymmetric representations of the gauge group. Simulations are performed for N=3,4,6 in all those representations, with the addition of N=2 for the adjoint representation. We illustrate a strategy for separating the even from the odd-power contributions in 1/N in the masses. Using this technique, we extrapolate the vector mass to the large-N limit in the chiral region and show that at N = infty this mass is the same within errors in all the three representations, as predicted by orientifold planar equivalence. Possible implications of our investigation for studying orientifold planar equivalence in the dynamical case are discussed.