2023/12/21 by Thorsten Feldmann, Feldmann, Thorsten, Nico Gubernari +1 · 2 citations
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions
paper · pdf · doi:10.48550/arxiv.2312.14146
openalex publication_date 2023/12/21 · openalex created_date 2023/12/23 · openalex updated_date 2026/07/28
We investigate for the first time a certain class of non-factorisable contributions of the four-quark operators \cal O3-6 in the weak effective Hamiltonian to the Λb → Λℓ+ℓ- decay amplitude. We focus on the case where a virtual photon is radiated from one of the light constituents of the Λb 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 Λb 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.