2011/02/06 by Urquijo, Phillip
#FOS: Physical sciences #High Energy Physics - Experiment (hep-ex)
paper · doi:10.48550/arxiv.1102.1160
I discuss the first semileptonic Bs decay measurements performed at LHCb, and the prospects for precise studies of Bs semileptonic decay properties. The analyses covered here are based on data collected with the LHCb detector in proton-proton collisions at a centre-of-mass energy of 7 TeV. In particular the semileptonic decays \Bs→ Ds+ X \munu and \Bs→ D0K+ X \munu are studied. Two structures are observed in the D0K+ mass spectrum at masses consistent with the known Ds1(2536)+ and D^*s2(2573)+ mesons. The measured branching fractions relative to the total \Bs semileptonic rate are \calB(\Bs→ Ds2*+ X \munu)/\calB(\Bs→ X \munu)= (3.3± 1.0± 0.4)%, and \calB(\Bs→ Ds1+ X \munu)/\calB(\Bs→ X \munu)= (5.4± 1.2(\rm stat)± 0.5(\rm sys))%. This is the first observation of the Ds2*+ state in \Bs decays.