Lepton flavor violating $\Lambda_b\to\Lambda\ell_1\ell_2$ decay

TL;DR

This paper investigates lepton flavor violating decays of the Lambda_b baryon, deriving decay distributions and asymmetries within a vector leptoquark model, motivated by recent anomalies in B-meson decays.

Contribution

It provides a detailed theoretical analysis of forbidden Lambda_b decays, including decay distributions and asymmetries, within a vector leptoquark framework, extending previous studies.

Findings

Derived decay distribution for Lambda_b to Lambda l1 l2

Constructed differential branching ratio and asymmetry

Constrained vector leptoquark model parameters using low energy data

Abstract

Inspired by the recent hints of lepton flavor universality violation in $b\to s\ell\ell$ and $b\to c\ell\nu$ transitions, we study lepton flavor violating exclusive $\Lambda_b\to\Lambda\ell_1^+\ell_2^-$ ($\ell_1\neq \ell_2$) decay, which is forbidden in the Standard Model. Starting from a general effective Hamiltonian for a $b\to s\ell_1^+\ell_2^-$ transition that includes vector and axial-vector operators, and scalar and pseudo-scalar operators, we derive a two-fold decay distribution of $\Lambda_b\to\Lambda\ell_1^+\ell_2^-$. The distribution helps us to construct the differential branching ratio and the lepton side forward-backward asymmetry, which are studied in a vector leptoquark model. The parameter space of the vector leptoquark model is constrained by low energy observables.