Measurement of the shape of the B_s⁰ → D_s^∗−µ⁺ν_µ differential decay rate

The shape of the B_s⁰ → D_s^∗−µ⁺ν_µ differential decay rate is obtained as a function of the hadron recoil 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_s⁰ → D_s^∗−µ⁺ν_µ decay is reconstructed through the decays D^∗− → D_s⁻γ and D_s⁻ → K⁻K⁺π⁻. The differential decay rate is fitted with the s Caprini-Lellouch-Neubert (CLN) and Boyd-Grinstein-Lebed (BGL) parametrisations of the form factors, and the relevant quantities for both are extracted.