Heavy quark expansion of $Λ_b\toΛ^*$ form factors beyond leading order

Marzia Bordone

Published 2021-01-28Version 1

I review the parametrisation of the full set of $\Lambda_b\to\Lambda^* (1520)$ form factors in the framework of Heavy Quark Expansion, including next-to-leading order $\mathcal{O}(\alpha_s)$ and for the first time next-to-leading power $\mathcal{O}(1/m_b)$ corrections. The unknown hadronic parameters are obtained performing a fit to a recent lattice QCD calculations. I investigate the compatibility of the HQE and the current lattice data, finding a tension between these two approaches in the case of tensor and pseudo-tensor form factors, whose origin could come from an underestimation of the current lattice QCD uncertainties and higher order terms in the HQE.