# Probing new physics in semileptonic $\Lambda_b$ decays

## TL;DR

This paper investigates potential new physics in semileptonic Lambda_b decays by analyzing deviations from lepton universality observed in B meson decays, constraining parameters with experimental data, and predicting various decay observables.

## Contribution

It provides a model-independent analysis of Lambda_b decays to explore new physics effects and lepton universality violation using current experimental constraints.

## Key findings

- Constraints on new physics parameters from B decay data
- Predicted branching ratios and asymmetries for Lambda_b decays
- Assessment of lepton universality violation in Lambda_b processes

## Abstract

In recent times, several hints of lepton non-universality have been observed in semileptonic $B$ meson decays, both in the charged-current ($b \to c l \bar \nu_l$) and neutral-current ($b \to s ll $) transitions. Motivated by these intriguing results, we perform a model independent analysis of the semileptonic $\Lambda_b$ decays involving the quark level transitions $b \to (u,c) l \nu_l$, in order to scrutinize the nature of new physics. We constrain the new parameter space by using the measured branching ratios of $B_{c, u}^+ \to \tau^+ \nu_\tau$, $B \to \pi \tau \nu_\tau$ processes and the existing experimental results on $R_{D^{(*)}}$, $R_{J/\psi}$ and $R_{\pi}^l$ parameters. Using the constrained parameters, we estimate the branching ratios, forward backward asymmetries, hadron and lepton polarization asymmetries of the $\Lambda_b \to (\Lambda_c, p) l \nu_l$ processes. Moreover, we also examine whether there could be any lepton universality violation in these decay modes.