Distribution Amplitudes of $K^*$ and $\phi$ at Physical Pion Mass from Lattice QCD

TL;DR

This paper reports the first lattice QCD calculation of the distribution amplitudes for $K^*$ and $mbda$ mesons at physical pion mass, providing essential theoretical inputs for exclusive process analysis.

Contribution

It introduces a novel lattice QCD approach using large momentum effective theory to compute vector meson distribution amplitudes at physical pion mass.

Findings

Longitudinal DAs are close to asymptotic form.

Transverse DAs deviate significantly from asymptotic form.

Results serve as ab initio inputs for exclusive process studies.

Abstract

We present the first lattice QCD calculation of the distribution amplitudes of longitudinally and transversely polarized vector mesons $K^*$ and $\phi$ using large momentum effective theory. We use the clover fermion action on three ensembles with 2+1+1 flavors of highly improved staggered quarks (HISQ) action, generated by MILC collaboration, at physical pion mass and \{0.06, 0.09, 0.12\} fm lattice spacings, and choose three different hadron momenta $P_z=\{1.29, 1.72, 2.15\}$ GeV. The resulting lattice matrix elements are nonperturbatively renormalized in a hybrid scheme proposed recently. An extrapolation to the continuum and infinite momentum limit is carried out. We find that while the longitudinal distribution amplitudes tend to be close to the asymptotic form, the transverse ones deviate rather significantly from the asymptotic form. Our final results provide crucial {\it ab initio} theory inputs for analyzing pertinent exclusive processes.