Study Of Orbitally Excited Bs Mesons And Evidence For A New B Pi Resonance With The Cdf Ii Detector PDF Download

This thesis describes investigations of the first set of orbitally excited (L = 1) states for both the Bd0 and Bs0 meson systems (B**d and B**s). The data sample corresponds to 1.35 fb-1 of integrated luminosity, collected in 2002-2006 by the D0 detector, during the Run IIa operation of the Tevatron p$\bar{p}$ colliding beam accelerator. The B**d states are fully reconstructed in decays to B(*)+ [pi]-, with B(*)+ → [gamma] J/[Psi]K+, J/[Psi] → [mu]+[mu]-, yielding 662 ± 91 events, and providing the first strong evidence for the resolution of two narrow resonances, B1 and B*2. The masses are extracted from a binned [Chi]2 fit to the invariant mass distribution, giving M(B1) = 5720.7 ± 2.4(stat.) ± 1.3(syst.) ± 0.5 (PDG) MeV/c2 and M(B*2) = 5746.9 ± 2.4(stat.) ± 1.0(syst.) ± 0.5(PDG) MeV/c2. The production rate of narrow B**d → B[pi] resonances relative to the B+ meson is determined to be [13.9 ± 1.9(stat.) ± 3.2(syst.)]%. The same B+ sample is also used to reconstruct the analogous states in the Bs0 system, in decays B**s → B(*)+ K-. A single resonance in the invariant mass distribution is found with a statistical significance of 5[sigma], interpreted as the B*s2 state. The mass is determined to be M(B*s2) = 5839.6 ± 1.1(stat.) ± 0.4(syst.) ± 0.5(PDG) MeV/c 2, and the production rate of B*s2 → BK resonances is measured to be a fraction (2.14 ± 0.43 ± 0.24)% of the corresponding rate for B+ mesons. Alternative fitting hypotheses give inconclusive evidence for the presence of the lighter Bs1 meson.