D semi-leptonic decay form factors with HISQ charm and light quarks

TL;DR

This paper explores D semi-leptonic decay form factors using HISQ charm and light quarks, introducing new methods for calculating form factors without operator renormalization on MILC gauge configurations.

Contribution

It develops a novel approach to compute $f_+(0)$ and $f_0(q^2)$ from scalar currents without renormalization, and determines form factors from vector currents with non-perturbative renormalization.

Findings

Successful calculation of $f_+(0)$ and $f_0(q^2)$ from scalar matrix elements.

Determination of $f_+(q^2)$ and $f_0(q^2)$ using non-perturbative renormalization.

First exploratory study of $D_s$ to $ ext{eta}_s$ semi-leptonic decay form factors with HISQ quarks.

Abstract

We present a program to study D semi-leptonic decay form factors with HISQ charm and light quarks. In this exploratory work, we study $D_s$ to $\eta_s$, $l\nu_l$ semi-leptonic decay on MILC coarse ($20^3\times64$) gauge configurations with 2+1 dynamical flavors. We develop a new method to calculate $f_+(0)$ and $f_0(q^2)$ from scalar current matrix elements, $<\pi|\bar{s}c|D>$, which does not require any operator renormalization. We also determine $f_+(q^2)$ and $f_0(q^2)$ from vector currents with a fully non-perturbative renormalization method.