A comprehensive study of $Λ_c^- \to Λ(\to p π) μ^- \bar ν_μ$ incorporating SMEFT implications and right-handed neutrino
Priyanka Boora, Siddhartha Karmakar, Dinesh Kumar, Kavita Lalwani
Published: 2025/10/6
Abstract
Charm baryon decays provide a complementary probe of new physics beyond the Standard Model. We study the decay $\Lambda_c^- \to \Lambda (p \pi) \mu^- \bar \nu_{\mu}$ in a model-independent effective field theory framework. This study covers both the left-handed and right-handed neutrino interactions in the $c \to s \mu \nu_{\mu}$ transition. For the left-handed neutrino operators, we incorporate the implications of the Standard Model effective field theory and do a global fit considering several observables sensitive to these operators. Based on the allowed parameter space of the new-physics operators, we analyze the differential rates, forward-backward asymmetries, polarization asymmetries of the final-state hadron and lepton in $\Lambda_c^- \to \Lambda \mu^- \bar \nu_{\mu}$, and the angular coefficients in 4-body angular distribution of $\Lambda_c^- \to \Lambda (\to p \pi) \mu^- \bar \nu_{\mu}$. Our results highlight distinctive signatures of certain operators involving right-handed quark currents and provide predictions that can be tested at BESIII, Belle II, and LHCb.