Measurement of the shape of the {B}_s^0to {D}_s^{ast -}{mu}^{+}{nu}_{mu } differential decay rate

Abstract

The shape of the {B}_s^0to {D}_s^{ast -}{mu}^{+}{nu}_{mu } differential decay rate is obtained as a function of the hadron recoil parameter using proton-proton collision data at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 1.7 fb−1 collected by the LHCb detector. The {B}_s^0to {D}_s^{ast -}{mu}^{+}{nu}_{mu } decay is reconstructed through the decays {D}_s^{ast -}to {D}_s^{-}gamma and {D}_s^{-}to {K}^{-}{K}^{+}{pi}^{-} . The differential decay rate is fitted with the Caprini-Lellouch-Neubert (CLN) and Boyd-Grinstein-Lebed (BGL) parametrisations of the form factors, and the relevant quantities for both are extracted.