D semileptonic form factors and |V_cs(d)| from 2+1 flavor lattice QCD

TL;DR

This paper presents lattice QCD calculations of semileptonic D meson decay form factors across multiple lattice spacings to precisely determine CKM matrix elements |V_cs| and |V_cd|, improving theoretical accuracy.

Contribution

It provides new lattice QCD results for D meson semileptonic form factors using 2+1 flavor ensembles, enabling more precise extraction of CKM elements.

Findings

Form factors can be determined with less than 5% uncertainty at zero invariant mass.

Lattice calculations agree with experimental form factor shapes.

Results facilitate more accurate CKM matrix element extraction.

Abstract

The measured partial widths of the semileptonic decays D to K l nu and D to pi l nu can be combined with the form factors calculated on the lattice to extract the CKM matrix elements |V_cs| and |V_cd|. The lattice calculations can be checked by comparing the form factor shapes from the lattice and experiment. We have generated a sizable data set by using heavy clover quarks with the Fermilab interpretation for charm and asqtad staggered light quarks on 2+1 flavor MILC ensembles with lattice spacings of approximately 0.12, 0.09, 0.06, and 0.045 fm. Preliminary fits to staggered chiral perturbation theory suggest that we can reduce the uncertainties in the form factors at zero invariant mass to below 5%.