680 research outputs found

    New interpretation of variational principles for gauge theories. I. Cyclic coordinate alternative to ADM split

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    I show how there is an ambiguity in how one treats auxiliary variables in gauge theories including general relativity cast as 3 + 1 geometrodynamics. Auxiliary variables may be treated pre-variationally as multiplier coordinates or as the velocities corresponding to cyclic coordinates. The latter treatment works through the physical meaninglessness of auxiliary variables' values applying also to the end points (or end spatial hypersurfaces) of the variation, so that these are free rather than fixed. [This is also known as variation with natural boundary conditions.] Further principles of dynamics workings such as Routhian reduction and the Dirac procedure are shown to have parallel counterparts for this new formalism. One advantage of the new scheme is that the corresponding actions are more manifestly relational. While the electric potential is usually regarded as a multiplier coordinate and Arnowitt, Deser and Misner have regarded the lapse and shift likewise, this paper's scheme considers new {\it flux}, {\it instant} and {\it grid} variables whose corresponding velocities are, respectively, the abovementioned previously used variables. This paper's way of thinking about gauge theory furthermore admits interesting generalizations, which shall be provided in a second paper.Comment: 11 page

    Measurements of Branching Fractions and Polarization in B > K^* rho Decays

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    We present results of a study of the charmless vector-vector decays B^0 -> K^{*0} rho^0 and B^+ ->K^{*0} rho^+. The results are based on a 140 fb^{-1} data sample collected by the Belle detector at the KEKB asymmetric e^+e^- collider. We obtain the branching fraction B(B^+ -> K^{*0} rho^+)=(6.6 +- 2.2(stat.) +- 0.8 (syst.)) x 10^{-6}, and set upper limits on the branching fractions B(B^0 -> K^{*0} rho^0) f_0(980) K^{*0})<5.2 x 10^{-6}. We also perform a helicity analysis of the rho and K^* vector mesons in the decay B^+ -> K^{*0} rho^+, and obtain the longitudinal polarization fraction R_0(B^+ -> K^{*0} rho^+)=0.50 +- 0.19(stat.)+0.05-0.07}(syst.).Comment: 11 pages, 4 figures, submitted to ICHEP04, Beijing, Chin

    Measurement of the branching fractions for B- --> D(*)+ pi- l- nu-bar and B0bar --> D(*)0 pi+ l- nu-bar

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    We report on a measurement of the branching fractions for B- --> D(*)+ pi- l- nu-bar and B0bar --> D(*)0 pi+ l- nu-bar with 275 million BBbar events collected at the Upsilon(4S) resonance with the Belle detector at KEKB. Events are tagged by fully reconstructing one of the B mesons in hadronic modes. We obtain Br(B- --> D+ pi- l- nu-bar) = (0.54 +/- 0.07(stat) +/- 0.07(syst) +/- 0.06(BR)) x 10^-2, Br(B- --> D*+ pi- l- nu-bar) = (0.67 +/- 0.11(stat) +/- 0.09(syst) +/- 0.03(BR)) x 10^-2, Br(B0bar --> D0 pi+ l- nu-bar) = (0.33 +/- 0.06(stat) +/- 0.06(syst) +/- 0.03(BR)) x 10^-2, Br(B0bar --> D*0 pi+ l- nu-bar) = (0.65 +/- 0.12(stat) +/- 0.08(syst) +/- 0.05(BR)) x 10^-2, where the third error comes from the error on Bbar --> D(*) l- nu-bar decays. Contributions from B0bar --> D*+ l- nu-bar decays are excluded in the measurement of B0bar --> D0 pi+ l- nu-bar.Comment: 6 pages, 10 figures, submitted to Physical Review D (Rapid Communication), the Lepton-Photon 2005 Conference (Uppsala, Sweden) and the HEP2005 Europhysics Conference (Lisboa, Portugal

    Improved measurement of time-dependent CP violation in B0 -> J/Psi pi0 decays

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    We report improved measurements of time-dependent CP violation parameters for B0(Bˉ0)J/ψπ0B^0(\bar{B}^0) \to J/\psi \pi^0 decay. This analysis is based on 535 million BBˉB\bar{B} pairs accumulated at the Υ(4S)\Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e^+e^- collider. From the distribution of proper time intervals between the two B decays, we obtain the following CP violation parameters SJ/ψπ0=0.65±0.21(stat)±0.05(syst)\mathcal{S}_{J/\psi \pi^0} = -0.65\pm0.21 (\rm{stat})\pm0.05 (\rm{syst}) and AJ/ψπ0=+0.08±0.16(stat)±0.05(syst)\mathcal{A}_{J/\psi \pi^0} = +0.08\pm0.16 (\rm{stat})\pm0.05 (\rm{syst}), which are consistent with Standard Model expectations.Comment: Resubmitted to PRD(RC), including 4 figures, 6pages Revision has been made according to communication with PRD referee

    Measurement of D0 -> pilnu (Klnu) Form Factors and Absolute Branching Fractions

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    Using a 282 1/fb data sample collected by the Belle experiment at the KEKB e+e- collider, we study D0 decays to K-l+nu and pi-l+nu final states. The D0 flavor and momentum are tagged through a full reconstruction of the recoiling charm meson and additional mesons from fragmentation. The reconstruction method provides very good resolution in neutrino momentum and in q^2 = (p_l+p_nu)^2. Normalizing to the total number of D0 tags, we measure the absolute branching fractions to be B(D0 -> Klnu) =(3.45 +- 0.07stat +- 0.20syst)% and B(D0 -> pilnu) = (0.255 +- 0.019stat +- 0.016syst)% and the semi-leptonic form factors (within the modified pole model) f+^K(0) = 0.695 +- 0.007stat +- 0.022syst and f+^pi(0) = 0.624 +- 0.020stat +- 0.030syst.Comment: 9 pages, 2 figures, submitted to Phys. Rev. Let

    Improved Measurements of Branching Fractions and CP Asymmetries in B-> eta h Decays

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    We report improved measurements of B decays with an eta meson in the final state using 492 fb^{-1} of data collected by the Belle detector at the KEKB e^+ e^- collider. We observe the decays B^{+-}-> eta pi^{+-} and B^{+-}-> eta K^{+-}; the measured branching fractions are Br(B^{+-}-> eta pi^{+-}) = (4.2+- 0.4(stat)+- 0.2(sys))x10^{-6} and Br(B^{+-}-> eta K^{+-}) = (1.9+-0.3(stat)^{+0.2}_{-0.1}(sys))x10^{-6}. The corresponding CP-violating asymmetries are measured to be -0.23+- 0.09(stat) +-0.02(sys) for eta pi^{+-} and -0.39+-0.16(stat)+-0.03(sys) for eta K^{+-}. We also search for B^0-> eta K^0 decays and set an upper limit of 1.9x10^{-6} at the 90% confidence level.Comment: 7 pages, 3 figure

    Time-dependent CP Asymmetries in B0KS0ρ0γB^0\to K^0_S\rho^0\gamma Decays

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    We report the first measurement of CP-violation parameters in B^0 -> K_S^0\rho^0\gamma decays based on 657 million B\bar B pairs collected with the Belle detector at the KEKB asymmetric-energy collider. We measure the time-dependent CP violating parameter S_{K_S^0\rho^0\gamma}= 0.11 +/- 0.33(stat.)^{+0.05}_{-0.09}(syst.). We also obtain the effective direct CP violating parameter A_eff=0.05 +/- 0.18(stat.) +/- 0.06(syst.) for m_{K_S\pi^+\pi^-}<1.8 GeV/c^2 and 0.6 GeV/c^2<m_{\pi^+\pi^-}<0.9 GeV/c^2.Comment: 6 pages, 3 figures, to be submitted to PR

    Observation of B+->Lambda_c+Lambda_c-K+ and B0->Lambda_c+Lambda_c^-K0 decays

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    We report first measurements of the doubly charmed baryonic B decays B->Lambda_c+Lambda_c-K. The B+->Lambda_c+Lambda_c-K+ decay is observed with a branching fraction of (6.5+1.0-0.9+-1.1+-3.4)x10^{-4} and a statistical significance of 15.4sigma. The B0->Lambda_c+Lambda_c-K0 decay is observed with a branching fraction of (7.9+2.9-2.3+-1.2+-4.2)x10^{-4} and a statistical significance of 6.6sigma. The branching fraction errors are statistical, systematic, and the error resulting from the uncertainty of Lambda_c+->pK-pi+ decay branching fraction. The analysis is based on 357fb-1 of data accumulated at the Y(4S) resonance with the Belle detector at the KEKB asymmetric e+e- collider.Comment: 10 pages, 3 figure

    Search for Bπ+B \to \pi \ell^+\ell^- Decays at Belle

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    We present a search for the B-> pi e^+ e^- and B-> pi \mu^+ \mu^- decays, with a data sample of 657 million BBbar pairs collected with the Belle detector at the KEKB e+ee^+e^- collider. Signal events are reconstructed from a charged or a neutral pion candidate and a pair of oppositely charged electrons or muons. No significant signal is observed and we set the upper limit on the isospin-averaged branching fraction BF(B -> \pi \ell^+\ell^-) < 6.2x10^-8 at the 90% confidence level.Comment: 8 pages, 3 figures, accepted by PRD(RC

    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
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