Measurement of Differential Production Cross Sections and Lifetime Ratio for Exclusive B^+ and B^0 Decays in pp Collisions at sqrt(s) = 10 TeV

We present a study to evaluate the feasibility of measuring with early CMS data the differential production cross section ($d\sigma/dp_T^B$) and lifetime ratio $\tau(B^+)/\tau(B^0)$ using fully reconstructed $\psik$ and $\psikst$ decays. The $\JPsi$ and $K^{*0}$ are reconstructed in the $\mu\mu$ and $K^+\pi^-$ channels, respectively, and the lifetime in each decay channel is determined in samples with $p_T^B> 9\,{\rm GeV}/c$ using an unbinned maximum likelihood fit to the invariant mass and proper decay length of the reconstructed $B$ candidates. The differential production cross section $d\sigma/dp_T^B$ is then determined separately in seven (four) bins of $p_T^B$ in the $B^+\,(B^0)$ samples using a similar two-dimensional fit with the lifetime fixed to the value measured over the full $p_T^B$ spectrum. In a sample of Monte Carlo simulated events equivalent to $10\invpb$, we demonstrate that the cross section and lifetime ratio can be determined with statistical uncertainties of $< 10\%$ and $\sim 5\%$, respectively.