The Volume Source Technique for flavor singlets: a second look

TL;DR

This paper improves the Volume Source Technique for calculating flavor singlet quantities on the lattice, especially addressing issues with fermions in real representations, and compares it with stochastic estimators in supersymmetric Yang-Mills theory.

Contribution

An improved version of the Volume Source Technique (IVST) is proposed, addressing its limitations for fermions in real representations and tested in supersymmetric Yang-Mills theory.

Findings

IVST outperforms traditional methods in certain cases

The method is applied to the spectrum analysis of SYM

Comparison shows advantages of IVST over stochastic estimators

Abstract

We reconsider the Volume Source Technique (VST) for the determination of flavor singlet quantities on the lattice. We point out a difficulty arising in the case of fermions in real representations of the gauge group and propose an improved version of the method (IVST) based on random gauge transformations of the background configuration. We compare the performance of IVST with the method based on stochastic estimators (SET). We consider the case of the N=1 Supersymmetric Yang-Mills Theory (SYM), where just one fermionic flavor is present, the gluino in the adjoint representation, and only flavor singlet states are possible. The work is part of an inclusive analysis of the spectrum of the lightest particles of the theory, based on the simulation of the model on a $16^3\cdot32$ lattice with dynamical gluinos in the Wilson scheme.