Transition form factors of the Λ_b → Λ(1520) in QCD light-cone sum rules

2024/12/09 by Huang, Ke-Sheng, Jiang, Hua-Yu, Yu, Fu-Sheng
#FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph)

paper · doi:10.48550/arxiv.2412.06515

Abstract

In this work, we investigate the transition form factors for Λ_b→Λ(1520) within the framework of light-cone sum rules (LCSR), using the light-cone distribution amplitudes (LCDAs) of the Λ_b-baryon. In the hadronic representation of the correlation function, we carefully select the appropriate Lorentz structures and isolate the contributions from both the Λ(1520)(J^P=(3/2)^-) and the Λ(1890)(J^P=(3/2)⁺), ensuring that the form factors for Λ_b→Λ(1520) can be calculated unambiguously. We also provide predictions for various physical observables in the decay Λ_b→Λ(1520)l⁺l^-, including the differential branching fraction, the lepton-side forward-backward asymmetry, the longitudinal polarization fraction, and the CP-averaged normalized angular observable. Our prediction for the differential branching fraction of Λ_b→Λ(1520)μ⁺μ^- is in good agreement with the LHCb measurement within the uncertainties.

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