$\Lambda_c \to \Lambda$ Form Factors in Lattice QCD

TL;DR

This paper calculates the form factors for the $mbda_c o mbda$ transition using lattice QCD, providing theoretical predictions relevant for understanding charm baryon semileptonic decays and testing the Standard Model.

Contribution

It presents the first lattice QCD computation of $mbda_c o mbda$ form factors, including Weinberg and helicity form factors, in the zero momentum transfer limit.

Findings

Form factors $f_1$, $f_2$, $g_1$ agree with models

Form factors $f_3$, $g_3$ are comparable to models

The $g_2$ form factor is mildly larger than previous estimates

Abstract

Studying the semileptonic decays of charmed particles is prominent in testing the standard model of particle physics. Motivated by recent experimental progress in weak decays of the charm baryon sector, we study the form factors of $\Lambda_c \to \Lambda \ell^+ \nu$ transition on two flavor lattices. We compute two- and three-point functions, extract the dimensionless projected correlators, and combine them to form the Weinberg form factors. In the zero transferred momentum limit $f_1$, $f_2$ and $g_1$ form factors are found to be in agreement with other models, furthermore $f_3$ and $g_3$ form factors are comparable to model determinations. The $g_2$ form factor, on the other hand, is found to be mildly larger. We also evaluate the helicity form factors, which is consistent with the previous lattice studies.