Analysis of $\Lambda_{b} \rightarrow$ $\Lambda \mu^{+} \mu^{-}$ decay in scalar leptoquark model

TL;DR

This paper investigates the $ ext{Lambda}_b o ext{Lambda} \, ext{mu}^+ ext{mu}^-$ decay within scalar leptoquark models, comparing predictions with experimental data and exploring effects on various observables.

Contribution

It introduces analysis of this decay process in two specific scalar leptoquark models and examines their impact on physical observables, highlighting where they improve agreement with data.

Findings

Standard Model predictions align with data in most $q^2$ ranges.

Scalar leptoquark models can better match data in some $q^2$ ranges.

Certain double lepton polarization asymmetries are sensitive to specific leptoquark models.

Abstract

We analyze the baryonic semilepton decay $\Lambda_{b} \rightarrow$ $\Lambda \mu^{+} \mu^{-}$ in the scalar leptoquark models with $X(3,2,7/6)$ and $X(3,2,1/6)$ states, respectively. We also discuss the effects of this two NP models on some physical observables. For some measured observables, like the differential decay width, the longitudinal polarization of the dilepton system, the lepton-side forward-backward asymmetry and the baryon-side forward-backward asymmetry, we find, the prediction values of SM are consistent with the current data in the most $q^{2}$ ranges, where the prediction values of this two NP models can also keep consistent with the current data with $1\sigma$. However, in some $q^{2}$ ranges, the prediction values of SM are difficult to meet the current data, but the contributions of this two NP models can meet them or keep closer to them. For the double lepton polarization asymmetries, $P_{LT}$, $P_{TL}$, $P_{NN}$ and $P_{TT}$ are sensitive to the scalar leptoquark model $X(3,2,7/6)$ but not to $X(3,2,1/6)$. However, $P_{LN}$, $P_{NL}$, $P_{TN}$ and $P_{NT}$ are not sensitive to this two NP models.