The glueball spectrum with $N_f=4$ light fermions

Abstract

We investigate the glueball spectrum for N f = 4 fermions corresponding to low pion masses of m π ∼ 250MeV. We do so by making use of configurations produced with maximally twisted fermions within the framework of the Extended Twisted Mass Collaboration (ETMC). We extract states that belong to irreducible representations of the octahedral group of rotations R in combination with the quantum numbers of charge conjugation C and parity P , i.e. R P C . We implement the Generalized Eigenvalue Problem (GEVP) using a basis consisting only of gluonic operators. The purpose of this work is to investigate the effect of light dynamical quarks on the glueball spectrum and how this compares to the statistically more accurate spectrum of the pure gauge theory. We employed large ensembles of the order of ∼ O(10K) configurations for each of three different lattice spacings. Our results demonstrate that in the scalar channel A ++ * Speaker