Amplitude analysis and branching fraction measurement of (B)over-bar(s)(0) -> J/psi K+K-

An amplitude analysis of the final state structure in the (B) over bar (0)(s) -> J/psi K+K- decay mode is performed using 1.0 fb(-1) of data collected by the LHCb experiment in 7 TeV center-of-mass energy pp collisions produced by the LHC. A modified Dalitz plot analysis of the final state is performed using both the invariant mass spectra and the decay angular distributions. Resonant structures are observed in the K+K- mass spectrum as well as a significant nonresonant S-wave contribution over the entire K+K- mass range. The largest resonant component is the phi(1020), accompanied by f(0)(980), f'(2)(1525), and four additional resonances. The overall branching fraction is measured to be B((B) over bar (0)(s) -> J/psi K+K-) = (7.70 +/- 0.08 +/- 0.39 +/- 0.60) x 10(-4), where the first uncertainty is statistical, the second systematic, and the third due to the ratio of the number of (B) over bar (0)(s) to B- mesons produced. The mass and width of the f'(2)(1525) are measured to be 1522.2 +/- 2.8(-2.0)(+5.3) MeV and 84 +/- 6(-5)(+10) MeV, respectively. The final state fractions of the other resonant states are also reported. DOI: 10.1103/PhysRevD.87.07200