We report a measurement of the B super(0) arrow right psi(2S)pi super(0) branching fraction based on the full Gamma(4S) data set of 772x10 super(6)BB pairs collected by the Belle detector at the KEKB ...asymmetric-energy e super(+)e super(?) collider. We obtain Bernoulli(B super(0) arrow right psi(2S)pi super(0))=(1.17 + or -0.17(stat)+ or -0.08(syst))x10 super(-5). The result has a significance of 7.2 standard deviations and is the first observation of the decay B super(0) arrow right psi(2S)pi super(0).
We report a measurement of the CP-violation parameter φ1 obtained in a time-dependent analysis of B0→D¯(*)0h0 decays followed by D¯0→KS0π+π− decay. A model-independent measurement is performed using ...the binned Dalitz plot technique. The measured value is φ1=11.7°±7.8°(stat)±2.1°(syst). Treating sin2φ1 and cos2φ1 as independent parameters, we obtain sin2φ1=0.43±0.27(stat)±0.08(syst) and cos2φ1=1.06±0.33(stat)−0.15+0.21(syst). The results are obtained with a full data sample of 772×106BB¯ pairs collected near the ϒ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e− collider.
Using a sample of 771.6×10(6) ϒϒ(4S) decays collected by the Belle experiment at the KEKB e(+)e(-) collider, we observe, for the first time, the transition ϒ(4S)→ηh(b)(1P) with the branching fraction ...Bϒ(4S)→ηh(b)(1P)=(2.18±0.11±0.18)×10(-3) and we measure the h(b)(1P) mass M(h(b)(1P))=(9899.3±0.4±1.0) MeV/c(2), corresponding to the hyperfine (HF) splitting ΔM(HF)(1P)=(0.6±0.4±1.0) MeV/c(2). Using the transition h(b)(1P)→γη(b)(1S), we measure the η(b)(1S) mass M(η(b)(1S))=(9400.7±1.7±1.6) MeV/c(2), corresponding to ΔM(HF)(1S)=(59.6±1.7±1.6) MeV/c(2), the η(b)(1S) width Γ(η(b)(1S))=(8(-5)(+6)±5) MeV/c(2) and the branching fraction Bh(b)(1P)→γη(b)(1S)=(56±8±4)%.
The branching fractions of the Υ(1S) inclusive decays into final states with a J/ψ or a ψ(2S) are measured with improved precision to be B(Υ(1S)→J/ψ+anything)=(5.25±0.13(stat)±0.25(syst))×10-4 and ...B(Υ(1S)→ψ(2S)+anything)=(1.23±0.17(stat)±0.11(syst))×10-4. The first search for Υ(1S) decays into XYZ states that decay into a J/ψ or a ψ(2S) plus one or two charged tracks yields no significant signals for XYZ states in any of the examined decay modes, and upper limits on their production rates in Υ(1S) inclusive decays are determined.
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)π^{+}π^{-} (n=1, 2) cross sections from ...thresholds up to 11.02 GeV. We find clear ϒ(10860) and ϒ(11020) peaks with little or no continuum contribution. We study the resonant substructure of the ϒ(11020)→h_{b}(nP)π^{+}π^{-} 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.
The Large Hadron Collider beauty (LHCb) experiment at CERN is undergoing an upgrade in preparation for the Run 3 data collection period at the Large Hadron Collider (LHC). As part of this upgrade, ...the trigger is moving to a full software implementation operating at the LHC bunch crossing rate. We present an evaluation of a CPU-based and a GPU-based implementation of the first stage of the high-level trigger. After a detailed comparison, both options are found to be viable. This document summarizes the performance and implementation details of these options, the outcome of which has led to the choice of the GPU-based implementation as the baseline.
The LHCb measurements on the B ->$ K^*$$\mu^+ \mu^-\( angular observables have shown slight deviations from their Standard Model predictions. The significance of the deviations in the B -> ...\)K^*$$\mu^+ \mu^-$ decay depends on the assumptions on the size of the non-factorisable power corrections. At present, there are no theoretical predictions on the size of these power corrections in order to identify whether the reason behind these anomalies is due to unknown hadronic corrections or New Physics effects. We have performed a statistical comparison of fitting the data to each of the possible explanations.
The well-known problem of the unknown power corrections within QCD improved factorisation leaves the interpretation of the so-called LHCb anomalies in the angular observables of B-->K* mu+ mu- as an ...open problem. In order to contribute to the question whether they represent a first sign for new physics beyond the Standard Model or a consequence of underestimated hadronic power corrections, we present a direct comparison of two global fits to the data based on the two different assumptions. In addition, we summarise the possible options to resolve this puzzle in the future.
Here, we report the result from the first search for D0 decays to invisible final states. The analysis is performed on a data sample of 924fb-1 collected at and near the Υ ( 4S ) and Υ ( 5S ) ...resonances with the Belle detector at the KEKB asymmetric-energy e+e- collider. The absolute branching fraction is confirmed using an inclusive D0 sample, obtained by fully reconstructing the rest of the particle system including the other charmed particle. No significant signal yield is observed and an upper limit of 9.4×10-5 is set on the branching fraction of D0 to invisible final states at 90% confidence level.
In this report, we search for a dark vector gauge boson U' that couples to quarks in the decay chain D*+ → D0π+,D0 → KS0η,η → U'γ , U' → π+π- . No signal is discovered and we set a mass-dependent ...limit on the baryonic fine structure constant of 10-3-10-2 in the U' mass range of 290 to 520MeV/c2 . This analysis is based on a data sample of 976fb-1 collected by the Belle experiment at the KEKB asymmetric-energy e+e- collider.
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