Semileptonic $D \rightarrow \pi \ell \nu$, $D \rightarrow K \ell \nu$ and $D_s \rightarrow K \ell \nu$ decays with 2+1f domain wall fermions

TL;DR

This paper reports on a lattice QCD study calculating semileptonic form factors for D meson decays using 2+1 flavor domain wall fermions, aiming to improve understanding of these processes across the full kinematic range.

Contribution

The study introduces a methodology for calculating D meson semileptonic form factors with domain wall fermions, including operator diagonalization and source optimization, across the full kinematic range.

Findings

Initial form factor results obtained from first ensembles.

Operator diagonalization strategies show effective ground state extraction.

Acceptable source combinations identified for zero and non-zero momentum.

Abstract

We present the status of our project to calculate $D \to \pi \ell \nu$, $D \to K \ell \nu$ and $D_s \to K \ell \nu$ semileptonic form factors using domain wall fermions for both heavy and light quarks. Our computations are performed using RBC/UKQCD's set of 2+1 flavour domain wall fermion and Iwasaki gauge field ensembles. We plan to calculate three-point functions covering the full, physically allowed kinematic range. Given that the signal decays faster than the noise, unambiguously and reliably extracting the ground state is critical for success. We include an analysis of operator diagonalisation within several possible $2 \times 2$ operator bases and find an admixture of gauged fixed wall and $\mathbb{Z} \left( 2 \right)$ wall sources to be acceptable at both zero and non-zero momentum. Initial results for semileptonic form factors are presented for first ensembles.