Lepton flavor violating decay

Diganta Das

doi:10.1140/epjc/s10052-019-7530-9

EPJ

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2023 Impact factor 4.2

Particles and Fields

Open Access

Eur. Phys. J. C (2019) 79: 1005
https://doi.org/10.1140/epjc/s10052-019-7530-9

Regular Article - Theoretical Physics

Lepton flavor violating $\Lambda _b\rightarrow \Lambda \ell _1\ell _2$ decay

Diganta Das^*

Department of Physics and Astrophysics, University of Delhi, Delhi, 110007, India

^* e-mail: diganta99@gmail.com

Received: 24 September 2019
Accepted: 29 November 2019
Published online: 12 December 2019

Abstract

Inspired by the recent hints of lepton flavor universality violation in $b\rightarrow s\ell \ell$ and $b\rightarrow c\ell \nu$ transitions, we study lepton flavor violating exclusive $\Lambda _b\rightarrow \Lambda \ell _1^+\ell _2^-$ ( $\ell _1\ne \ell _2$ ) decay, which is forbidden in the Standard Model. Starting from a general effective Hamiltonian for a $b\rightarrow s\ell _1^+\ell _2^-$ transition that includes vector and axial-vector operators, and scalar and pseudo-scalar operators, we derive a two-fold decay distribution of $\Lambda _b\rightarrow \Lambda \ell _1^+\ell _2^-$ . 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.