Nucleon scalar matrix elements with $N_f=2+1+1$ twisted mass fermions

TL;DR

This paper calculates nucleon scalar matrix elements for light and strange quarks using $N_f=2+1+1$ twisted mass fermions, employing noise reduction and multiplicative renormalization for precise results.

Contribution

It introduces an efficient noise reduction technique and applies multiplicative renormalization to accurately compute scalar matrix elements with twisted mass fermions.

Findings

Accurate scalar matrix elements for light and strange quarks obtained.

Disconnection contributions computed with noise reduction techniques.

Results consistent with previous lattice QCD studies.

Abstract

We investigate scalar matrix elements of the nucleon using $N_f=2+1+1$ flavors of maximally twisted mass fermions at a fixed value of the lattice spacing of $a\approx 0.078{\rm fm}$. We compute disconnected contributions to the relevant three-point functions using an efficient noise reduction technique. Using these methods together with an only multiplicative renormalization applicable for twisted mass fermions, allows us to obtain accurate results in the light and strange sector.