Transition form factors and angular distributions of the $\bm{\Lambda_b\to\Lambda(1520)(\to N\bar{K})\ell^+\ell^-}$ decay supported by baryon spectroscopy

TL;DR

This paper calculates the form factors and angular distributions of the rare decay mbda_b2 with a focus on baryon spectroscopy, using a light-front quark model supported by potential model wave functions.

Contribution

It introduces a novel approach combining a three-body light-front quark model with a potential model to compute mbda_b2 transition form factors, reducing uncertainties from wave function choices.

Findings

Form factors calculated with reduced model uncertainties.

Predictions for angular distributions in mbda_b2 decay.

Results can aid future experimental analysis at LHCb.

Abstract

We calculate the weak transition form factors of the $\Lambda_b\to\Lambda(1520)$ transition, and further calculate the angular distributions of the rare decays $\Lambda_b\to\Lambda(1520)(\to N\bar{K})\ell^{+}\ell^{-}$ ($N\bar{K}=\{pK^-,n\bar{K}^0\}$) with unpolarized $\Lambda_b$ and massive leptons. The form factors are calculated by the three-body light-front quark model with the support of numerical wave functions of $\Lambda_b$ and $\Lambda(1520)$ from solving the semirelativistic potential model associated with the Gaussian expansion method. By fitting the mass spectrum of the observed single bottom and charmed baryons, the parameters of the potential model are fixed, so this strategy can avoid the uncertainties arising from the choice of a simple harmonic oscillator wave function of the baryons. With more data accumulated in the LHCb experiment, our result can help for exploring the $\Lambda_b\to\Lambda(1520)\ell^+\ell^-$ decay and deepen our understanding on the $b\to s\ell^+\ell^-$ processes.