Study of Λb → Λℓ+ℓ− (ℓ = e,μ,τ) decays in the G(221) model

Abstract

We study respectively the baryonic semilepton decays [Formula: see text][Formula: see text] in the [Formula: see text] model, which includes the tree-level flavor-changing-neutral-currents (FCNCs) induced by [Formula: see text] and [Formula: see text] bosons and modifies the Wilson coefficients [Formula: see text] and [Formula: see text]. For the form factors, we use the results of QCD light-cone sum rules (LCSR) in the low [Formula: see text] region and lattice QCD in the high [Formula: see text] region, respectively. We consider the effects of this new physics (NP) model on some measured physical observables, like the differential branching ratio, the longitudinal polarization of the dilepton system, the lepton-side forward–backward asymmetry and the baryon-side forward–backward asymmetry, and find, obvious differences occur in some observables between the Standard Model (SM) and this NP model. Meanwhile, we also discuss the double lepton polarization asymmetries of these decay channels, and find, [Formula: see text], [Formula: see text] and [Formula: see text] of these decay channels are sensitive to the contribution of this NP model.