Citation Link: https://doi.org/10.1007/jhep03(2024)152
Non-factorisable contributions of strong-penguin operators in Λb → Λℓ+ℓ− decays
Publication Type
Article
Author(s)
Subjects
Physics
PArticle physics
Theoretical physics
Date Issued
2024
Abstract
We investigate for the first time a certain class of non-factorisable contributions of the four-quark operators $$ \mathcal{O} $$ 3 − 6 in the weak effective Hamiltonian to the Λ b → Λ ℓ + ℓ − decay amplitude. We focus on the case where a virtual photon is radiated from one of the light constituents of the Λ b baryon, in the kinematic situation of large hadronic recoil with an energetic Λ baryon in the final state. The effect on the suitably defined “non-local form factors” is calculated using the light-cone sum rule approach for a correlator with an interpolating current for the light Λ baryon. We find that this approach requires the introduction of new soft functions that generalise the standard light-cone distribution amplitudes (LCDAs) for the heavy Λ b baryon. We give a heuristic discussion of their properties and a model that relates them to the standard LCDAs. Within this framework, we provide numerical results for the size of the non-local form factors considered.
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