Pion and Kaon Distribution Amplitudes from lattice QCD: towards the continuum limit

TL;DR

This paper reports on a lattice QCD study calculating pion and kaon distribution amplitude moments, using multiple lattice spacings and physical pion masses to approach the continuum limit with improved statistical methods.

Contribution

It introduces a non-perturbative lattice approach with combined continuum and chiral extrapolation for distribution amplitudes, utilizing momentum smearing for enhanced precision.

Findings

Successful calculation of distribution amplitude moments at physical pion mass.

Reduction of excited state contamination through momentum smearing.

Progress towards continuum limit with multiple lattice spacings.

Abstract

We present the current status of a non-perturbative lattice calculation of the moments of the pion and kaon distribution amplitudes by the RQCD collaboration. Our investigation is carried out using $N_f=2+1$ dynamical, non-perturbatively O(a)-improved Wilson fermions on the CLS ensembles with 5 different lattice spacings and pion masses down to the physical pion mass. A combined continuum and chiral extrapolation to the physical point is performed along two independent quark mass trajectories simultaneously. We employ momentum smearing in order to decrease the contamination by excited states and increase statistical precision.