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PubMed | German Electron Synchrotron, University of the Basque Country, Korea Institute of Science and Technology, Yonsei University and 55 more.
Type: Journal Article | Journal: Physical review letters | Year: 2015

Using a sample of 771.610(6) (4S) decays collected by the Belle experiment at the KEKB e(+)e(-) collider, we observe, for the first time, the transition (4S)h(b)(1P) with the branching fraction B[(4S)h(b)(1P)]=(2.180.110.18)10(-3) and we measure the h(b)(1P) mass M(h(b)(1P))=(9899.30.41.0)MeV/c(2), corresponding to the hyperfine (HF) splitting M(HF)(1P)=(0.60.41.0)MeV/c(2). Using the transition h(b)(1P)(b)(1S), we measure the (b)(1S) mass M((b)(1S))=(9400.71.71.6)MeV/c(2), corresponding to M(HF)(1S)=(59.61.71.6)MeV/c(2), the (b)(1S) width ((b)(1S))=(8(-5)(+6)5)MeV/c(2) and the branching fraction B[h(b)(1P)(b)(1S)]=(5684)%.


PubMed | Karlsruhe Institute of Technology, Gifu University, National United University, National Research Nuclear University MEPhI and 63 more.
Type: Journal Article | Journal: Physical review letters | Year: 2016

We report the first observation of the decay _{c}^{+}pK^{+}^{-} using a 980fb^{-1} data sample collected by the Belle detector at the KEKB asymmetric-energy e^{+}e^{-} collider. This is the first observation of a doubly Cabibbo-suppressed decay of a charmed baryon. We measure the branching ratio of this decay with respect to its Cabibbo-favored counterpart to be B(_{c}^{+}pK^{+}^{-})/B(_{c}^{+}pK^{-}^{+})=(2.350.270.21)10^{-3}, where the uncertainties are statistical and systematic, respectively.


PubMed | Karlsruhe Institute of Technology, National Research Nuclear University MEPhI, University of the Basque Country, Korea Institute of Science and Technology and 57 more.
Type: Journal Article | Journal: Physical review letters | Year: 2016

We report the analysis of the three-body e^{+}e^{-}BB[over ]^{}, BB[over ]^{*}^{}, and B^{*}B[over ]^{*}^{} processes, including the first observations of the Z_{b}^{}(10610)[BB[over ]^{*}+c.c.]^{} and Z_{b}^{}(10650)[B^{*}B[over ]^{*}]^{} transitions that are found to dominate the corresponding final states. We measure Born cross sections for the three-body production of (e^{+}e^{-}[BB[over ]^{*}+c.c.]^{}^{})=[17.41.6(stat)1.9(syst)]pb and (e^{+}e^{-}[B^{*}B[over ]^{*}]^{}^{})=[8.751.15(stat)1.04(syst)]pb and set a 90%C.L. upper limit of (e^{+}e^{-}[BB[over ]]^{}^{})<2.9pb. The results are based on a 121.4fb^{-1} data sample collected with the Belle detector at a center-of-mass energy near the (10860) peak.


PubMed | Punjab Agricultural University, Gifu University, National United University, German Electron Synchrotron and 64 more.
Type: Journal Article | Journal: Physical review letters | Year: 2016

We measure the decay B_{s}^{0}K^{0}K[over ]^{0} using data collected at the (5S) resonance with the Belle detector at the KEKB e^{+}e^{-} collider. The data sample used corresponds to an integrated luminosity of 121.4fb^{-1}. We measure a branching fraction B(B_{s}^{0}K^{0}K[over ]^{0})=[19.6_{-5.1}^{+5.8}(stat)1.0(syst)2.0(N_{B_{s}^{0}B[over ]_{s}^{0}})]10^{-6} with a significance of 5.1 standard deviations. This measurement constitutes the first observation of this decay.


PubMed | Karlsruhe Institute of Technology, National United University, German Electron Synchrotron, University of the Basque Country and 64 more.
Type: Journal Article | Journal: Physical review letters | Year: 2016

Using data collected with the Belle detector at the KEKB asymmetric-energy e^{+}e^{-} collider, we measure the energy dependence of the e^{+}e^{-}h_{b}(nP)^{+}^{-} (n=1, 2) cross sections from thresholds up to 11.02GeV. We find clear (10860) and (11020) peaks with little or no continuum contribution. We study the resonant substructure of the (11020)h_{b}(nP)^{+}^{-} transitions and find evidence that they proceed entirely via the intermediate isovector states Z_{b}(10610) and Z_{b}(10650). The relative fraction of these states is loosely constrained by the current data: The hypothesis that only Z_{b}(10610) is produced is excluded at the level of 3.3 standard deviations, while the hypothesis that only Z_{b}(10650) is produced is not excluded at a significant level.

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