SEARCH FOR GLUEBALLS IN THE PRESENCE OF DYNAMICAL QUARKS

Glueball spectroscopy in the presence of dynamical quarks faces a number of obstacles. Not only is there a signal-to-noise problem heavily affecting purely gluonic operators, but also flavour-singlet energy eigenstates of the theory are a mixture of mesonic and gluonic degrees of freedom. Tackling these issues requires large statistics and operators with large overlap onto energy eigenstates of interest. We present results for the glueball spectrum with and without dynamical quarks using a wide variety of Wilson loop shapes, which work well for the quenched case but are heavily affected by excited-state contamination when dynamical quarks are introduced. For the latter case, flavour-singlet meson operators based on the framework of optimized distillation are included and show that energy eigenstates have significant contributions from both types of operators. © 2024 Jagiellonian University. All rights reserved.