Puzzles in charmed baryon semileptonic decays

TL;DR

This paper develops a systematic framework to analyze semileptonic decays of singly charmed baryons, addressing recent discrepancies between experimental data and lattice QCD, and predicts specific branching ratios to clarify the source of observed SU(3)_F breaking.

Contribution

It introduces a method combining lattice QCD inputs with SU(3)_F symmetry analysis including first-order breaking, providing precise decay ratio predictions.

Findings

Predicted branching ratio ${ m B}(\Xi_c^+ o\Sigma^0\ell^+ u_\ell)/{ m B}(\Xi_c^+ o\Xi^0\ell^+ u_\ell)=(2.6\pm0.3)\%$

Predicted branching ratio ${ m B}(\Xi_c^+ o\Lambda^0\ell^+ u_\ell)/{ m B}(\Xi_c^+ o\Xi^0\ell^+ u_\ell)=(1.1\pm0.1)\%$

Addresses the puzzle of large SU(3)_F breaking in charmed baryon decays.

Abstract

Large apparent $SU(3)_F$ breaking and a tension with lattice QCD have recently emerged in semileptonic decays of singly charmed baryons, hinting at either an unexpected hadronic mechanism or new physics. We formulate a framework that systematically matches lattice-QCD inputs onto an $SU(3)_F$ analysis including first-order symmetry breaking. We predict ${\mathcal{B}}(\Xi_c^+\to\Sigma^0\ell^+\nu_\ell)/{\mathcal{B}}(\Xi_c^+\to\Xi^0\ell^+\nu_\ell)=(2.6\pm0.3)\%,$ and ${\mathcal{B}}(\Xi_c^+\to\Lambda^0\ell^+ \nu_\ell)/{\mathcal{B}}(\Xi_c^+\to\Xi^0\ell^+\nu_\ell)=(1.1\pm0.1)\%$, whose precise measurements would cleanly determine the origin of the anomalously large $SU(3)_F$ breaking.