Lepton polarization asymmetries for FCNC decays of the Λ_b baryon

2015/06/12 by L. Mott, W. Roberts
Physics and Astronomy · #nucl-th #hep-ex #hep-ph

paper · pdf · doi:10.1142/s0217751x15501729

44 pages, 34 figures, To be submitted to IJMPA. arXiv admin note: substantial text overlap with arXiv:1108.6129

arxiv created 2015/06/12 · arxiv updated 2015/10/28

Abstract

Branching ratios, lepton forward-backward asymmetries, and lepton polarization asymmetries for the flavor-changing neutral current (FCNC) dileptonic decays of the Λ_b baryon to the ground state and a number of excited state Λ baryons are calculated using form factors extracted using wave functions from a constituent quark model. The SM branching ratios for the transition to the ground state calculated using these quark model form factors are consistent with the recent measurement reported by the LHCb collaboration. It is shown that the lepton polarization asymmetries are largely insensitive to the transition form factors and, therefore, to the effects of QCD in the nonperturbative regime. These observables can therefore provide somewhat model independent ways of extracting various combinations of the Wilson coefficients.

Citations

• Rare dileptonic decays of Λ_b in a quark model