In the era of high-luminosity hadronic colliders, the rare heavy-to-light decay Lambda_b to Lambda l+ l- receives increasing research attention in both experimental and theoretical particle phenomenology. This flavour-changing neutral-current decay is a potential window for the discovery of new Physics beyond the Standard Model through its helicity-sensitive nature, complementing past and ongoing searches and calculations related to the B meson.
In this work the universal soft form factor in the heavy-quark and large-recoil limits is calculated using light-cone sum rules in the framework of soft-collinear effective theory, as is the O(alpha_s) correction from hard-collinear gluon exchange.
Numerical estimates on form-factor ratios and experimental observables are presented. Related issues, including baryonic transition form factors and in particular light-cone distribution amplitudes for the heavy baryon Lambda_b, are also discussed
