1,290 research outputs found

    Chiral dynamics and B to 3 pi decay

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    I discuss our knowledge of the scalar sector of QCD and how it impacts the determination of the CKM angle \alpha from the isospin analysis of B\to \rho\pi decay.Comment: invited talk at International Workshop on Heavy Quarks and Leptons, Vietri sul Mare, Salerno, Italy, 27 May - 1 Jun 200

    Generator Coordinate Truncations

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    We investigate the accuracy of several schemes to calculate ground-state correlation energies using the generator coordinate technique. Our test-bed for the study is the sdsd interacting boson model, equivalent to a 6-level Lipkin-type model. We find that the simplified projection of a triaxial generator coordinate state using the S3S_3 subgroup of the rotation group is not very accurate in the parameter space of the Hamiltonian of interest. On the other hand, a full rotational projection of an axial generator coordinate state gives remarkable accuracy. We also discuss the validity of the simplified treatment using the extended Gaussian overlap approximation (top-GOA), and show that it works reasonably well when the number of boson is four or larger.Comment: 19 pages, 6 eps figure

    Isoscalar-isovector mass splittings in excited mesons

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    Mass splittings between the isovector and isoscalar members of meson nonets arise in part from hadronic loop diagrams which violate the Okubo-Zweig-Iizuka rule. Using a model for these loop processes which works qualitatively well in the established nonets, I tabulate predictions for the splittings and associated isoscalar mixing angles in the remaining nonets below about 2.5 GeV, and explain some of their systematic features. The results for excited vector mesons compare favorably with experiment.Comment: 8 RevTeX pages, including 1 LaTeX figure. CMU-HEP93-23/DOE-ER-40682-4

    Properties of the Strange Axial Mesons in the Relativized Quark Model

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    We studied properties of the strange axial mesons in the relativized quark model. We calculated the K1K_1 decay constant in the quark model and showed how it can be used to extract the K1(3P1)−K1(1P1)K_1 (^3P_1) - K_1 (^1P_1) mixing angle (ΞK\theta_K) from the weak decay τ→K1Μτ\tau \to K_1 \nu_\tau. The ratio BR(τ→ΜτK1(1270))/BR(τ→ΜτK1(1400))BR(\tau \to \nu_\tau K_1 (1270))/BR(\tau\to \nu_\tau K_1(1400)) is the most sensitive measurement and also the most reliable since the largest of the theoretical uncertainties factor out. However the current bounds extracted from the TPC/Two-Gamma collaboration measurements are rather weak: we typically obtain −30oâ‰ČΞKâ‰Č50o-30^o \lesssim \theta_K \lesssim 50^o at 68\% C.L. We also calculated the strong OZI-allowed decays in the pseudoscalar emission model and the flux-tube breaking model and extracted a 3P1−1P1^3P_1 - ^1P_1 mixing angle of ΞK≃45o\theta_K \simeq 45^o. Our analysis also indicates that the heavy quark limit does not give a good description of the strange mesons.Comment: Revised version to be published in Phys. Rev. D. Minor changes. Latex file uses revtex version 3 and epsfig, 4 postcript figures are attached. The full postcript version with embedded figures is available at ftp://ftp.physics.carleton.ca/pub/theory/godfrey/ocipc9512.ps.

    Diquarks and Exotic Spectroscopy

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    We propose that the recently discovered \Theta baryon is a bound state of four quarks and an antiquark, containing two highly correlated ud-pairs. If so, the \Theta baryon has positive parity, and it lies in an near-ideally mixed SU(3)_{f} \mathbf{\bar{10}}_{f} oplus \mathbf{8}_{f}. The Roper resonance and the P_{11}(1710) fit naturally into this classification. We predict an isospin 3/2 multiplet of \Xi's (S=-2) with J^{\Pi}=\half^{+} around 1750 MeV. A search for manifestly exotic \Xi^{+} and \Xi^{--} in this mass range could provide a sharp test of our proposal. We predict that charm and bottom analogues of the \Theta baryon are stable against strong decays.Comment: 5 pages, 2 figures, revtex 4, minor corrections and revisions for journal publicatio

    Why is the B -> eta' X decay width so large ?

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    New mechanism for the observed inclusive B -> \eta'X decay is suggested. We argue that the dominant contribution to this amplitude is due to the Cabbibo favored b -> \bar{c}cs process followed by the transition \bar{c}c -> \eta'. A large magnitude of the "intrinsic charm" component of \eta' is of critical importance in our approach. Our results are consistent with an unexpectedly large Br(B -> \eta'+X) \sim 10^{-3} recently announced by CLEO. We stress the uniqueness of this channel for 0^{-+} gluonia search.Comment: Comments on a mixing model for intrinsic charm and pre-asymptotic effects and some references are added. Latex, 9 page

    A model independent and rephase invariant parametrization of CP violation

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    The phenomenological description of the neutral B meson system is proposed in terms of the fundamental CP-violating observables and within a rephasing invariant formalism. This generic formalism can select the time-dependent and time-integrated asymmetries which provide the basic tools to discriminate the different kinds of possible CP-violating effects in dedicated experimental B-meson facilities.Comment: 19 pages, Plain Te

    Final-State Phases in Doubly-Cabibbo-Suppressed Charmed Meson Nonleptonic Decays

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    Cabibbo-favored nonleptonic charmed particle decays exhibit large final-state phase differences in Kˉπ\bar K \pi and Kˉ∗π\bar K^* \pi but not Kˉρ\bar K \rho channels. It is of interest to know the corresponding pattern of final-state phases in doubly-Cabibbo-suppressed decays, governed by the c→dusˉc \to d u \bar s subprocess. An experimental program is outlined for determining such phases via measurements of rates for D→K∗πD \to K^* \pi and K(ρ,ω,ϕ)K (\rho, \omega,\phi) channels, and determination of interference between bands in Dalitz plots. Such a program is feasible at planned high-intensity sources of charmed particles.Comment: 12 pages, LaTeX, 2 figures, to be submitted to Phys. Rev. D. Revised versio

    Branching ratios of the decays of psi(3770) and Upsilon(10580) into light hadrons

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    Taking into account the new data on the full width of D^{\ast\pm}(2010) and the mass difference of the charged and neutral beauty mesons B^\pm, B^0,\bar B^0, the branching ratios of the decays psi(3770), Upsilon(10580) to pi^+pi^-, K bar K, rho(omega)pi, rho(omega)eta, rho(omega)eta^prime, K^ast bar K+ c.c, rho^+ rho^-, and K^ast bar K^ast are re-evaluated in the model in which the Okubo-Zweig-Iizuka rule is violated due to the real intermediate state D\bar D in case of psi(3770) and B\bar B in case of Upsilon(10580). The inclusive annihilation of psi(3770) and Upsilon(10580) into light hadrons is discussed.Comment: 10 page

    Compositeness Effects in the Bose-Einstein Condensation

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    Small deviations from purely bosonic behavior of trapped atomic Bose-Einstein condensates are investigated with the help of the quon algebra, which interpolates between bosonic and fermionic statistics. A previously developed formalism is employed to obtain a generalized version of the Gross-Pitaeviskii equation. Two extreme situations are considered, the collapse of the condensate for attractive forces and the depletion of the amount of condensed atoms with repulsive forces. Experimental discrepancies observed in the parameters governing the collapse and the depletion of the condensates can be accounted for by universal fittings of the deformation parameter for each case.Comment: 17 pages, 1 tabl
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