Measurement of the branching ratio of a B meson decaying to a J/psi meson, a kaon, and two pions

This thesis reports a measurement of the branching ratio of the decay B'^ —>• J/V^K^7r^7r~. The data sample consists of 110 pb~^ of pp collisions at a center of mass energy of 1.8 TeV, collected by the Collider Detector at Fermilab (CDF). This data was collected during Run I of the Tevatron from 1992 through 1995. The J/I!J meson is reconstructed via the decay channel J/ip —> p^p~• Signals of 40.4 ± 9.0 B^ -^ J/ipK'^7T'^7T~ and 270±18 B+ -^ J/ipK^ events are observed and we determine the ratio of branching ratios BR(S+ -^ J/ipK+TT+n-)/ BR(B+ ^ J/^pK+). Then by using the world average value for BR(5+ -^ J/ipK'^), we calculate the branching ratio BR(5+ -^ J/i^K+n+n-) to be (1.19 ± 0.28(stat) ± 0.15 sys)) x IQ-^