SCET sum rules for Λb → Λℓ+ℓ−, Λγ decays

We construct light-cone sum rules for various types of effective form factors in the Λ_b → Λℓ⁺ℓ⁻ and Λ_b → Λγ decays by analyzing vacuum-to-Λ_b (or γ^*-to-Λ_b) correlation functions with the light Λ-baryon interpolating current. These form factors, defined via hadronic matrix elements within soft-collinear effective theory (SCET), enter the next-to-leading-power QCD factorization formulas for large-recoil transitions. Implementing the perturbative matching from SCET_I to heavy quark effective theory, we determine the hard-collinear functions at next-to-leading-order accuracy. Based on light-cone sum rule predictions for the Λ_b → Λ form factors, we compute the q²-dependent differential branching fraction, forward-backward asymmetry and dilepton longitudinal polarization fraction for Λ_b → Λℓ⁺ℓ⁻ decay, as well as the branching fraction for Λ_b → Λγ decay.