We perform an analysis of Λb→Λ(1520) local form factors. We
use dispersive techniques to provide a model-independent parametrisation of the
form factors that can be used in the whole kinematic region. We use lattice QCD
data to constrain the free parameters in the form factors expansion, which is
further constrained by endpoint relations, dispersive bounds, and SCET
relations. We analyse different scenarios, where we expand the form factors up
to different orders, and their viability. Finally, we use our results to obtain
predictions for some observables in Λb→Λ(1520)ℓ+ℓ−
decays, as the differential branching ratio, the forward-backwards lepton
asymmetry and the branching ratio of Λb→Λ(1520)γ.
Finally, we provide a python notebook based on the software EOS to reproduce
our result.Comment: 21 pages, 4 figures, 1 ancillary file, v2: correction of typos, v3:
version accepted in JHE