106 research outputs found

    Search for the lepton-flavor-violating decays Bs0→e±μ∓ and B0→e±μ∓

    Get PDF
    A search for the lepton-flavor-violating decays Bs0→e±μ∓ and B0→e±μ∓ is performed with a data sample, corresponding to an integrated luminosity of 1.0  fb-1 of pp collisions at √s=7  TeV, collected by the LHCb experiment. The observed number of Bs0→e±μ∓ and B0→e±μ∓ candidates is consistent with background expectations. Upper limits on the branching fractions of both decays are determined to be B(Bs0→e±μ∓)101  TeV/c2 and MLQ(B0→e±μ∓)>126  TeV/c2 at 95% C.L., and are a factor of 2 higher than the previous bounds

    Search for the standard model Higgs boson at LEP

    Get PDF

    Measurement of cos2β\cos{2\beta} in B0D()h0B^{0} \to D^{(*)} h^{0} with DKS0π+πD \to K_{S}^{0} \pi^{+} \pi^{-} decays by a combined time-dependent Dalitz plot analysis of BaBar and Belle data

    Get PDF
    We report measurements of sin2β\sin{2\beta} and cos2β\cos{2\beta} from a time-dependent Dalitz plot analysis of B0D()h0B^{0} \to D^{(*)} h^{0} with DKS0π+πD \to K_{S}^{0} \pi^{+} \pi^{-} decays, where the light unflavored and neutral hadron h0h^{0} is a π0\pi^{0}, η\eta, or ω\omega meson. The analysis is performed with a combination of the final data sets of the \babar\ and Belle experiments containing 471×106471 \times 10^{6} and 772×106772 \times 10^{6} BBˉB\bar{B} pairs collected at the Υ(4S)\Upsilon\left(4S\right) resonance at the asymmetric-energy B factories PEP-II at SLAC and KEKB at KEK, respectively. We measure sin2β=0.80±0.14(stat.)±0.06(syst.)±0.03(model)\sin{2\beta} = 0.80 \pm 0.14 \,(\rm{stat.}) \pm 0.06 \,(\rm{syst.}) \pm 0.03 \,(\rm{model}) and cos2β=0.91±0.22(stat.)±0.09(syst.)±0.07(model)\cos{2\beta} = 0.91 \pm 0.22 \,(\rm{stat.}) \pm 0.09 \,(\rm{syst.}) \pm 0.07 \,(\rm{model}). The result for the direct measurement of the angle is β=(22.5±4.4(stat.)±1.2(syst.)±0.6(model))\beta = \left( 22.5 \pm 4.4 \,(\rm{stat.}) \pm 1.2 \,(\rm{syst.}) \pm 0.6 \,(\rm{model}) \right)^{\circ}. The last quoted uncertainties are due to the composition of the D0KS0π+πD^{0} \to K_{S}^{0} \pi^{+} \pi^{-} decay amplitude model, which is newly established by a Dalitz plot amplitude analysis of a high-statistics e+eccˉe^{+}e^{-} \to c\bar{c} data sample as part of this analysis. We find the first evidence for cos2β>0\cos2\beta>0 at the level of 3.73.7 standard deviations. The measurement excludes the trigonometric multifold solution π/2β=(68.1±0.7)\pi/2 - \beta = (68.1 \pm 0.7)^{\circ} at the level of 7.37.3 standard deviations and therefore resolves an ambiguity in the determination of the apex of the CKM Unitarity Triangle. The hypothesis of β=0\beta = 0^{\circ} is ruled out at the level of 5.15.1 standard deviations, and thus CP violation is observed in B0D()h0B^{0} \to D^{(*)} h^{0} decays.Comment: To be submitted to Physical Review

    It’s Not Only Rents: Explaining the Persistence and Change of Neopatrimonialism in Indonesia

    Full text link
    Indonesia has long been associated with neopatrimonialism, corruption, collusion, and nepotism as the main modi operandi of politics, economics and public administration. Despite various measures and initiatives to fight these practises, little evidence for a significant decline can be found over the years. Rather, longitudinal analysis points to changes in the character of neopatrimonialism. Based on more than 60 in-depth interviews, focus-group discussions, and the analysis of both primary and secondary data, the aim of this article is, first, to describe the changes that have taken place, and, second, to investigate what accounts for these changes. Political economy concepts posit the amount and development of economic rents as the explanatory factor for the persistence and change of neopatrimonialism. This study's findings, however, indicate that rents alone cannot explain what has taken place in Indonesia. Democratisation and decentralisation exert a stronger impact

    Measurement of the very rare K+π+ννˉK^+ \to \pi^+ \nu \bar\nu decay

    Get PDF
    The decay K+→π+νν¯ , with a very precisely predicted branching ratio of less than 10−10 , is among the best processes to reveal indirect effects of new physics. The NA62 experiment at CERN SPS is designed to study the K+→π+νν¯ decay and to measure its branching ratio using a decay-in-flight technique. NA62 took data in 2016, 2017 and 2018, reaching the sensitivity of the Standard Model for the K+→π+νν¯ decay by the analysis of the 2016 and 2017 data, and providing the most precise measurement of the branching ratio to date by the analysis of the 2018 data. This measurement is also used to set limits on BR(K+→π+X ), where X is a scalar or pseudo-scalar particle. The final result of the BR(K+→π+νν¯ ) measurement and its interpretation in terms of the K+→π+X decay from the analysis of the full 2016-2018 data set is presented, and future plans and prospects are reviewed

    Amplitude analysis of the radiative decay Bs0 → K+K−γ

    Get PDF
    A search for radiative decay of B0 s mesons to orbitally excited K+K− states is performed using proton proton collisions recorded by the LHCb experiment, corresponding to an integrated luminosity of 9 fb−1 . The dikaon spectrum in the mass range mKK < 2400 MeV/c 2 is dominated by the ϕ(1020) resonance that accounts for almost 70% of the decay rate. Considering the possible contributions of f2(1270), f ′ 2 (1525) and f2(2010) meson states, the overall tensor contribution to the amplitude is measured to be F{f2} = 16.8 ± 0.5 (stat.) ± 0.7 (syst.)%, mostly dominated by the f ′ 2 (1525) state. Several statistically equivalent solutions are obtained for the detailed resonant structure depending on whether the smaller amplitudes interfere destructively or constructively with the dominant amplitude. The preferred solution that corresponds to the lowest values of the ft fractions along with constructive interference leads to the relative branching ratio measurement B(B0 s → f ′ 2γ) B(B0 s → ϕγ) = 19.4 +0.9 −0.8 (stat.) +1.4 −0.5 (syst.) ± 0.5 (B)%, where the last uncertainty is due to the ratio of measured branching fractions to the K+K− final state. This result represents the first observation of the radiative B0 s → f ′ 2 (1525)γ decay, which is the second radiative transition observed in the B0 s sector

    Study of b-hadron decays to Λc^+h-h' final states

    Get PDF
    Decays of Ξ − b and Ω − b baryons to Λ + c h −h ′− final states, with h −h ′− being π −π −, K−π\ud − and K−K− meson pairs, are searched for using data collected with the LHCb detector. The data sample studied corresponds to an integrated luminosity of 8.7 fb−1 of pp collisions collected at centre-of-mass energies √ s = 7, 8 and 13 TeV. The products of the relative branching fractions and fragmentation fractions for each signal mode, relative to the B− → Λ + c pπ− mode, are measured, with Ξ − b → Λ + c K−π −, Ξ − b → Λ + c K−K− and Ω − b → Λ + c K−K− decays being observed at over 5 σ significance. The Ξ − b → Λ + c K−π − mode is also used to measure the Ξ − b production asymmetry, which is found to be consistent with zero. In addition, the B− → Λ + c pK− decay is observed for the first time, and its branching fraction is measured relative to that of the B− → Λ + c pπ− mode
    corecore