Simulation of 4d N=1 supersymmetric Yang-Mills theory with Symanzik improved gauge action and stout smearing

TL;DR

This paper presents a numerical lattice simulation of 4D N=1 SU(2) Supersymmetric Yang-Mills theory using improved gauge actions and smearing techniques, exploring the low-lying spectrum and supermultiplet formation.

Contribution

It introduces a detailed lattice simulation approach with Symanzik improvement and stout smearing to study supersymmetric gauge theories with dynamical gluinos.

Findings

The gluino-glue state is heavier than the pseudoscalar at lightest gluino mass.

Simulations were performed on large lattices with controlled lattice spacing.

Supermultiplet formation remains an open question for future research.

Abstract

We report on the results of a numerical simulation concerning the low-lying spectrum of four-dimensional N=1 SU(2) Supersymmetric Yang-Mills (SYM) theory on the lattice with light dynamical gluinos. In the gauge sector the tree-level Symanzik improved gauge action is used, while we use the Wilson formulation in the fermion sector with stout smearing of the gauge links in the Wilson-Dirac operator. The ensembles of gauge configurations were produced with the Two-Step Polynomial Hybrid Monte Carlo (TS-PHMC) updating algorithm. We performed simulations on large lattices up to a size of 24^3 x 48 at $\beta=1.6$. Using QCD units with the Sommer scale being set to r_0 = 0.5 fm, the lattice spacing is about a ~ 0.09 fm, and the spatial extent of the lattice corresponds to 2.1 fm. At the lightest simulated gluino mass the spin-1/2 gluino-glue bound state appeared to be considerably heavier than its expected super-partner, the pseudoscalar bound state. Whether supermultiplets are formed remains to be studied in upcoming simulations.