The first observation of the decay B0s→ϕK¯∗0 is reported. The analysis is based on a data sample corresponding to an integrated luminosity of 1.0 fb−1 of pp collisions at s√=7TeV, collected with the LHCb detector. A yield of 30±6 B0s→(K+K−)(K−π+) decays is found in the mass windows 1012.5<M(K+K−)<1026.5MeV/c2 and 746<M(K−π+)<1046MeV/c2. The signal yield is found to be dominated by B0s→ϕK¯∗0 decays, and the corresponding branching fraction is measured to be (B0s→ϕK¯∗0)=(1.10±0.24(stat)±0.14(syst)±0.08(fd/fs))×10−6, where the uncertainties are statistical, systematic and from the ratio of fragmentation fractions fd/fs which accounts for the different production rate of B0 and B0s mesons. The significance of B0s→ϕK¯∗0 signal is 6.1 standard deviations. The fraction of longitudinal polarization in B0s→ϕK¯∗0 decays is found to be f0=0.51±0.15(stat)±0.07(syst).
First observation of the decay $ B_s^0\to \phi \overline{K}{*^0} $
BALDINI, Wander;BOZZI, Concezio;FIORE, Marco;SAVRIE', Mauro;
2013
Abstract
The first observation of the decay B0s→ϕK¯∗0 is reported. The analysis is based on a data sample corresponding to an integrated luminosity of 1.0 fb−1 of pp collisions at s√=7TeV, collected with the LHCb detector. A yield of 30±6 B0s→(K+K−)(K−π+) decays is found in the mass windows 1012.5I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.