Comparative analysis of the semileptonic $\Lambda_b \rightarrow \Lambda \ell^+ \ell^-$ transition in SM and different SUSY scenarios using form factors from full QCD

TL;DR

This paper compares the semileptonic Lambda_b to Lambda decay in the Standard Model and various SUSY models using form factors from full QCD, analyzing decay rates and asymmetries to identify deviations and favored scenarios.

Contribution

It provides a detailed calculation of decay amplitudes and observables in SUSY models using full QCD form factors, extending previous analyses.

Findings

Differential branching ratios vary across SUSY models.

Lepton forward-backward asymmetry shows significant deviations from SM predictions.

Certain SUSY scenarios are favored based on the analysis.

Abstract

We work out the semileptonic $\Lambda_b\rightarrow \Lambda \ell^+ \ell^-$ transition in standard as well as different supersymmetric models. In particular, considering the parametrization of the matrix elements entered the low energy effective Hamiltonian in terms of form factors in full QCD, we calculate the amplitude and differential decay rate responsible for this decay channel in supersymmetric models. We then use the form factors calculated via light cone QCD sum rules in full theory to analyze the differential branching ratio and lepton forward-backward asymmetry of this decay channel in different supersymmetric models and compare the obtained results with those of the standard model. We also discuss how the results of different supersymmetric models deviate from the standard model predictions and which SUSY scenarios are favored.