Observation of Tree-LevelBDecays withss¯Production from Gluon Radiation
B. Aubert, M. Bona, D. Boutigny, Y. Karyotakis, J. P. Lees, V. Poireau, X. Prudent, V. Tisserand, A. Zghiche, J. Garra Tico, E. Grauges, L. Lopez
(+563 others)
2008
Physical Review Letters
We report on our search for B^- → D^(*)+_s K^- π^-, B̅^̅0̅→ D_s^(*)+ K_S^0 π^-, and B^- → D^(*)+_s K^- K^- decays in 383 million → B events collected by the Babar detector at the PEP2 asymmetric-energy B-factory. The decays proceed via a tree-level b→ c quark transition in which a gluon radiates into an ss̅ pair. Their branching fractions are measured to be B(B^- → D^+_s K^- π^-) = (2.02 ± 0.13_stat± 0.38_syst) × 10^-4, B(B^- → D^*+_s K^- π^-)= (1.67 ± 0.16_stat± 0.35_syst) × 10^-4, B(B̅^̅0̅→
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... s^+ K_S^0 π^-)= (0.55 ± 0.13_stat± 0.10_syst) × 10^-4, and B(B^- → D_s^+ K^- K^-) = (0.11 ± 0.04_stat± 0.02_syst) × 10^-4. Upper limits at the 90 are set on B(B̅^̅0̅→ D_s^*+ K_S^0 π^-)< 0.55 × 10^-4 and B(B^- → D_s^*+ K^- K^-) < 0.15 × 10^-4. We present evidence that the invariant mass distributions of D^(*)+_s K^- pairs from B^- → D^(*)+_s K^- π^- decays are inconsistent with the phase-space model, suggesting the presence of charm resonances lying below the D^(*)+_s K^- threshold.
doi:10.1103/physrevlett.100.171803
pmid:18518280
fatcat:detrcnsa6rgnbavsvzftcgqr2y
