825 research outputs found

    THE ARMY AND THE 1980s

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    Ds+ϕρ+D_s^+ \to \phi \rho^+ Decay

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    Motivated by the experimental measurement of the decay rate, Γ\Gamma, and the longitudinal polarization, PLP_L, in the Cabibbo favored decay Ds+ϕρ+D_s^+\to \phi {\rho}^{+}, we have studied theoretical prediction within the context of factorization approximation invoking several form factors models. We were able to obtain agreement with experiment for both Γ\Gamma and PLP_L by using experimentally measured values of the form factors A1Dsϕ(0)A_1^{D_s\phi}(0), A2Dsϕ(0)A_2^{D_s\phi}(0) and VDsϕ(0)V^{D_s\phi}(0) in the semi-leptonic decay Ds+ϕl+νlD_s^+\to \phi l^{+}\nu_{l}. We have also included in our calculation the effect of the final state interaction (fsifsi) by working with the partial waves amplitudes SS, PP and DD. Numerical calculation shows that the decay amplitude is dominated by SS wave, and that the polarization is sensitive to the interference between SS and DD waves. The range of the phase difference δSD=δSδD\delta_{SD} = \delta_S - \delta_D accommodated by experimental error in PLP_L is large.Comment: 7 pages, LaTe

    Nonfactorization and the decays Ds+ϕπ+,ϕρ+D_s^+ \to \phi \pi^+, \phi \rho^+ and ϕl+νl\phi l^+ \nu_l

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    In six chosen scenarios for the q2q^2 dependence of the form factors involved in Ds+ϕD_s^+ \rightarrow \phi transition, we have determined the allowed domain of x=A2(0)/A1(0)x = A_2(0) / A_1(0) and y=V(0)/A1(0)y = V(0)/A_1(0) from the experimentally measured ratios Rsl=Γ(Ds+ϕl+νl)/Γ(Ds+ϕπ+)R_{sl} = \Gamma(D_s^+ \rightarrow \phi l^+ \nu_l)/\Gamma(D_s^+ \rightarrow \phi \pi^+) and Rh=Γ(Ds+ϕρ+)/Γ(Ds+ϕπ+)R_h = \Gamma(D_s^+ \rightarrow \phi \rho^+)/\Gamma(D_s^+ \rightarrow \phi \pi^+) in a scheme that uses the Nc=3N_c =3 value of the phenomenological parameter a1a_1 and includes nonfactorized contribution. We find that the experimentally measured values of xx and yy from semileptonic decays of Ds+D_s^+ favor solutions which have significant nonfactorized contribution, and, in particular, RslR_{sl} favors solutions in scenarios where A1(q2)A_1(q^2) is either flat or decreasing with q2q^2.Comment: 15 pages, Latex, four figure (available on request)

    Snowmass CF1 Summary: WIMP Dark Matter Direct Detection

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    As part of the Snowmass process, the Cosmic Frontier WIMP Direct Detection subgroup (CF1) has drawn on input from the Cosmic Frontier and the broader Particle Physics community to produce this document. The charge to CF1 was (a) to summarize the current status and projected sensitivity of WIMP direct detection experiments worldwide, (b) motivate WIMP dark matter searches over a broad parameter space by examining a spectrum of WIMP models, (c) establish a community consensus on the type of experimental program required to explore that parameter space, and (d) identify the common infrastructure required to practically meet those goals.Comment: Snowmass CF1 Final Summary Report: 47 pages and 28 figures with a 5 page appendix on instrumentation R&

    Critical Analysis of Theoretical Estimates for BB to Light Meson Form Factors and the BψK(K)B \to \psi K(K^{\ast}) Data

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    We point out that current estimates of form factors fail to explain the non-leptonic decays BψK(K)B \to \psi K(K^{\ast}) and that the combination of data on the semi-leptonic decays DK(K)νD \to K(K^{\ast})\ell \nu and on the non-leptonic decays BψK(K)B \to \psi K(K^{\ast}) (in particular recent po\-la\-ri\-za\-tion data) severely constrain the form (normalization and q2q^2 dependence) of the heavy-to-light meson form factors, if we assume the factorization hypothesis for the latter. From a simultaneous fit to \bpsi and \dk data we find that strict heavy quark limit scaling laws do not hold when going from DD to BB and must have large corrections that make softer the dependence on the masses. We find that A1(q2)A_1(q^2) should increase slower with \qq than A2,V,f+A_2, V, f_+. We propose a simple parametrization of these corrections based on a quark model or on an extension of the \hhs laws to the \hl case, complemented with an approximately constant A1(q2)A_1(q^2). We analyze in the light of these data and theoretical input various theoretical approaches (lattice calculations, QCD sum rules, quark models) and point out the origin of the difficulties encountered by most of these schemes. In particular we check the compatibility of several quark models with the heavy quark scaling relations.Comment: 48 pages, DAPNIA/SPP/94-24, LPTHE-Orsay 94/1

    Heavy Meson Decays into Light Resonances

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    We analyse the Lorentz structures of weak decay matrix elements bewteen meson states of arbitrary spin. Simplifications arise in the transition amplitudes for a heavy meson decaying into a light one via a Bethe-Salpeter approach which incorporates heavy quark symmetry. Phenomenological consequences on several semileptonic, nonleptonic and FCNC induced decays of heavy flavoured mesons are derived and discussed.Comment: 20 RevTex pages, Preprint # UTAS-PHYS-94-0
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