412 research outputs found

    CP Violating B ---> s Gamma Decay in Supersymmetric Models

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    Supersymmetric models with nonuniversal down type squark masses can enrich the chiral structure and CP violating phenomena in bsγb\to s\gamma decays. Direct CP violation in bsγb\to s \gamma, mixing induced CP violation in radiative Bd,sB_{d,s} decays (such as BsϕγB_s\to \phi \gamma and BdK1,2γB_d \to K^*_{1,2}\gamma), and Λ\Lambda polarization in ΛbΛγ\Lambda_b \to \Lambda \gamma can be substantially different from the Standard Model. Future experiements at e+ee^+ e^- and hadronic B factories will give important information on the underlying theory for radiative bb decays.Comment: 19 pages, 8 figures, Latex. To appear in Phys. Rev.

    Evidence for a narrow dip structure at 1.9 GeV/c2^2 in 3π+3π3\pi^+ 3\pi^- diffractive photoproduction

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    A narrow dip structure has been observed at 1.9 GeV/c2^2 in a study of diffractive photoproduction of the  3π+3π~3\pi^+3\pi^- final state performed by the Fermilab experiment E687.Comment: The data of Figure 6 can be obtained by downloading the raw data file e687_6pi.txt. v5 (2nov2018): added Fig. 7, the 6 pion energy distribution as requested by a reade

    Search for Resonant B±K±hK±γγB^{\pm}\to K^{\pm} h \to K^{\pm} \gamma \gamma Decays at Belle

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    We report measurements and searches for resonant B±K±hK±γγB^{\pm} \to K^{\pm} h \to K^{\pm} \gamma \gamma decays where hh is a η,η,ηc,ηc(2S),χc0,χc2,J/ψ\eta,\eta^{\prime},\eta_{c},\eta_{c}(2S),\chi_{c0},\chi_{c2},J/\psi meson or the X(3872) particle.Comment: accepted by Physics Letters

    Study of charmonia in four-meson final states produced in two-photon collisions

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    We report measurements of charmonia produced in two-photon collisions and decaying to four-meson final states, where the meson is either a charged pion or a charged kaon. The analysis is based on a 395fb^{-1} data sample accumulated with the Belle detector at the KEKB electron-positron collider. We observe signals for the three C-even charmonia eta_c(1S), chi_{c0}(1P) and chi_{c2}(1P) in the pi^+pi^-pi^+pi^-, K^+K^-pi^+pi^- and K^+K^-K^+K^- decay modes. No clear signals for eta_c(2S) production are found in these decay modes. We have also studied resonant structures in charmonium decays to two-body intermediate meson resonances. We report the products of the two-photon decay width and the branching fractions, Gamma_{gamma gamma}B, for each of the charmonium decay modes.Comment: 22 pages, 12 figure

    Search for B+ -> D*+ pi0 decay

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    We report on a search for the doubly Cabibbo suppressed decay B+ -> D*+ pi0, based on a data sample of 657 million BBbar pairs collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric energy e+ e- collider. We find no significant signal and set an upper limit of Br(B+ -> D*+ pi0) < 3.6 x 10^-6 at the 90% confidence level. This limit can be used to constrain the ratio between suppressed and favored B -> D* pi decay amplitudes, r < 0.051, at the 90% confidence level.Comment: 5pages, 2figures, submitted to PRL (v1); PRL published version (v2: minor corrections in the text

    Search for Lepton-Flavor-Violating tau Decays into a Lepton and an f0(980) Meson

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    We search for lepton-flavor-violating tau decays into a lepton (electron or muon) and an f0(980) meson using 671 fb-1 of data collected with the Belle detector at the KEKB asymmetric-energy e+e- collider. No events are observed and we set the following 90% C.L. upper limits on the branching fraction products: B(tau- -> e-f0(980))*B(f0(980)->pi+pi-) mu-f0(980))*B(f0(980) -> pi+pi-)<3.4x10^-8. This is the first search performed for these modes.Comment: 10 pages, 4 figures, submitted to Phys. Lett.

    Observation of the ϕ(1680)\phi(1680) and the Y(2175) in e+eϕπ+πe^+ e^- \to \phi\pi^+\pi^-

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    The cross sections for e+eϕπ+πe^+ e^- \to \phi\pi^+\pi^- and e^+ e^- \to \phi \fzero are measured from threshold to s=3.0\sqrt{s}=3.0 GeV\hbox{GeV} using initial state radiation. The analysis is based on a data sample of 673 fb1^{-1} collected on and below the Υ(4S)\Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+ee^+e^- collider. First measurements are reported for the resonance parameters of the ϕ(1680)\phi(1680) in the ϕπ+π\phi\pi^+\pi^- mode: m=(1689±7±10)m=(1689\pm 7\pm 10) MeV/c2c^2 and Γ=(211±14±19)\Gamma=(211\pm 14\pm 19) MeV/c2c^2. A structure at s=2.1GeV/c2\sqrt{s}=2.1 \hbox{GeV}/c^2, corresponding to the so called Y(2175), is observed; its mass and width are determined to be 2079±1328+792079\pm13^{+79}_{-28} MeV/c2c^2 and 192±2361+25MeV/c2192\pm23^{+25}_{-61} \hbox{MeV}/c^2, respectively.Comment: 11 pages, 6 figures. Add one plot. Accepted by Phys.Rev.D(RC

    Determinants of Carbon Emission Disclosures and UN Sustainable Development Goals: The Case of UK Higher Education Institutions

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    In recent years, organisational sustainability has become a topical issue in many institutional fields and a number of calls have been made to improve the disclosure of carbon information as part of sustainability efforts. This paper responds to these calls, chiefly examining the determinants of (CED) in the annual reports of UK higher education institutions (HEIs). It also aims to predict the relationship between the extent of CED and UN Sustainable Development Goals (SDGs) reporting by UK universities. We construct a disclosure index to capture the extent and type of CED in the annual reports of UK HEIs, finding that carbon reduction targets imposed by the Government, environmental audit, and the amount of actual carbon emissions are significant and positively associated with CED. However, we find no relationship between CED and the disclosure of SDGs. We argue that HEIs'. CED can be useful in developing relevant regulatory policies given the targets are carefully set. Our research has important implications for policymakers regarding carbon reduction targets and related non?mandatory guidance, as these can be utilised as an effective mechanism in increasing carbon emission disclosure voluntary CED that are integrated into SDG disclosures

    Observation of Ds1(2536)+ -> D+pi-K+ and angular decomposition of Ds1(2536)+ -> D*+K0S

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    Using 462/fb of e+e- annihilation data recorded by the Belle detector, we report the first observation of the decay Ds1(2536)+ -> D+pi-K+. The ratio of branching fractions B(Ds1+ -> D+pi-K+)/B(Ds1+ -> D*+K0) is measured to be (3.27+-0.18+-0.37)%. We also study the angular distributions in the Ds1(2536)+ -> D*+K0S decay and measure the ratio of D- and S-wave amplitudes. The S-wave dominates, with a partial width of Gamma_S/Gamma_total=0.72+-0.05+-0.01.Comment: Submitted to Phys.Rev.D 16 pages, 6 figures, 3 table

    Search for lepton-flavor-violating τV0\tau\to\ell V^0 decays at Belle

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    We have searched for neutrinoless τ\tau lepton decays into \ell and V0V^0, where \ell stands for an electron or muon, and V0V^0 for a vector meson (ϕ\phi, ω\omega, K0K^{*0}, Kˉ0\bar{K}^{*0} or ρ0\rho^0), using 543 fb1^{-1} of data collected with the Belle detector at the KEKB asymmetric-energy e+ee^+e^- collider. No excess of signal events over the expected background has been observed, and we set upper limits on the branching fractions in the range (5.918)×108(5.9-18) \times 10^{-8} at the 90% confidence level. These upper limits include the first results for the ω\ell \omega mode as well as new limits that are significantly more restrictive than our previous results for the ϕ\ell \phi, K0\ell K^{*0}, Kˉ0\ell \bar{K}^{*0} and ρ0\ell \rho^0 modes.Comment: 7 pages, 16 figure
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