Rare $ \Lambda_c $ decays and new physics effects

TL;DR

This paper calculates form factors for rare $\,\Lambda_c$ decays using QCD sum rules, predicts branching ratios, and explores potential new physics effects through angular observables, highlighting the importance of baryonic decays in testing beyond Standard Model theories.

Contribution

It provides a comprehensive set of form factors for $\,\Lambda_c\to p$ transitions and analyzes new physics effects in baryonic rare decays, extending previous studies with detailed calculations and phenomenological predictions.

Findings

Predicted branching fractions for $\,\Lambda_c\to p e^+ e^-$ and $\,\Lambda_c\to p \mu^+ \mu^-$.

Identified potential signals of new physics in angular observables.

Demonstrated the relevance of baryonic decays in probing beyond Standard Model physics.

Abstract

Recent experimental progress on baryonic rare decays has spurred a deeper investigation on flavor-changing neutral current transitions in the baryon sector. Within the framework of QCD sum rules, we derive a complete set of form factors for the $ \Lambda_c\to p $ process in the large recoil region and use the $z$-series parametrization to extrapolate them across the full physical range. Employing these form factors and flavor symmetries, we compute branching fractions for the decays $\Lambda_c \to p e^+ e^-$ and $\Lambda_c \to p \mu^+ \mu^-$, as well as for rare $ \Xi_c $ decay modes. We examine as well the new physics effects through specific angular observables such as the lepton forward-backward asymmetry and the fraction of longitudinally polarized dileptons. Results indicate that new physics models may be testified in baryonic rare decays, with immense data collected in running and future colliders.