1,128 research outputs found

    Third-order non-Coulomb correction to the S-wave quarkonium wave functions at the origin

    Full text link
    We compute the third-order correction to the S-wave quarkonium wave functions |\psi_n(0)|^2 at the origin from non-Coulomb potentials in the effective non-relativistic Lagrangian. Together with previous results on the Coulomb correction and the ultrasoft correction computed in a companion paper, this completes the third-order calculation up to a few unknown matching coefficients. Numerical estimates of the new correction for bottomonium and toponium are given.Comment: 12 pages, v2: matches published version, missing factors in eq. (9), (29) adde

    Quarkonium production and NRQCD matrix elements

    Get PDF
    Most recent calculations of quarkonium production are based on the NRQCD factorization formalism. This formalism is reviewed. To make predictions about specific cross section, universal NRQCD matrix elements need to be extracted from experiments. Extractions from different experimental situations are compared, with some emphasis on the extraction from LEP.Comment: 6 pages, 1 figure, talk given at 4th International Conference on Hyperons, Charm and Beauty Hadrons, Valencia, Spain, 27-30 Jun 200

    Third-order Coulomb corrections to the S-wave Green function, energy levels and wave functions at the origin

    Full text link
    We obtain analytic expressions for the third-order corrections due to the strong interaction Coulomb potential to the S-wave Green function, energy levels and wave functions at the origin for arbitrary principal quantum number n. Together with the known non-Coulomb correction this results in the complete spectrum of S-states up to order alpha_s^5. The numerical impact of these corrections on the Upsilon spectrum and the top quark pair production cross section near threshold is estimated.Comment: 24 pages, LaTeX, v2: eq.(30) corrected (-13/8->-15/8

    SCET sum rules for heavy-to-light form factors

    Full text link
    We consider a sum rule for heavy-to-light form factors in soft-collinear effective theory (SCET). Using the correlation function given by the time-ordered product of a heavy-to-light current and its hermitian conjugate, the heavy-to-light soft form factor zeta_P can be related to the leading-order B meson shape function. Using the scaling behavior of the heavy-to-light form factor in Lambda_QCD/m_b, we put a constraint on the behavior of the BB meson shape function near the endpoint. We employ the sum rule to estimate the size of zeta_P with the model for the shape function and find that it ranges from 0.01 to 0.07.Comment: 11 pages, 5 figure

    NNNLO correction to the toponium and bottomonium wave-functions at the origin

    Full text link
    We report new results of the NNNLO correction to the S-wave quarkonium wave-functions at the origin, which also provide an estimate of the resonance cross section in t-tbar threshold production at the ILC.Comment: 5 pages, 2 figures, Proceedings of 2007 International Linear Collider Workshop: LCWS07 and ILC07, Hamburg, Germany, 30 May - 3 Jun 200

    B ->\eta_c K(\eta_c^\prime K) decays in QCD factorization

    Full text link
    We study the exclusive decays of BB meson into pseudoscalar charmonium states ηc\eta_c and ηc\eta_c^\prime within the QCD factorization approach and find that the nonfactorizable corrections to naive factorization are infrared safe at leading-twist order. The spectator interactions arising from the kaon twist-3 effects are formally power-suppressed but chirally and logarithmically enhanced. The theoretical decay rates are too small to accommodate the experimental data. On the other hand, we compare the theoretical calculations for J/ψ,ψJ/\psi, \psi^\prime, and ηc,ηc\eta_c, \eta_c^\prime, and find that the predicted relative decay rates of these four states are approximately compatible with experimental data.Comment: 8 pages, LaTex, 1 figure, one footnote and two references adde

    B meson light-cone wavefunctions in the heavy quark limit

    Get PDF
    We present a systematic study of the B meson light-cone wavefunctions in QCD in the heavy-quark limit. We construct model-independent formulae for the light-cone wavefunctions in terms of independent dynamical degrees of freedom, which exactly satisfy the QCD equations of motion and constraints from heavy-quark symmetry. The results demonstrate novel behaviors of longitudinal as well as transverse momentum distribution in the B mesons.Comment: 5 pages LaTeX, 1 style file. Talk presented at RADCOR/Loops and Legs 2002, Kloster Banz, Germany, September 8-13, 200

    Charmless BPPB \to PP decays and the new physics effects in the minimal supergravity model

    Full text link
    By employing the QCD factorization approach, we calculate the new physics contributions to the branching radios of the two-body charmless BPP B \to PP decays in the framework of the minimal supergravity (mSUGRA) model. Within the considered parameter space, we find that (a) the supersymmetric (SUSY) corrections to the Wilson coefficients CkC_k (k=36k=3-6) are very small and can be neglected safely, but the leading order SUSY contributions to C7γ(MW)C_{7\gamma}(M_W) and C8g(MW)C_{8g}(M_W) can be rather large and even change the sign of the corresponding coefficients in the standard model; (b) the possible SUSY contributions to those penguin-dominated decays in mSUGRA model can be as large as 305030-50%; (c) for the well measured BKπB \to K \pi decays, the significant SUSY contributions play an important rule to improve the consistency of the theoretical predictions with the data; (d) for BKηB \to K \eta' decays, the theoretical predictions of the corresponding branching ratios become consistent with the data within one standard deviation after the inclusion of the large SUSY contributions in the mSUGRA model.Comment: 31 pages, Latex file, 4 ps and eps figures, minor corrections, final version to appear in Physical Review

    Radiative B decays to the axial KK mesons at next-to-leading order

    Full text link
    We calculate the branching ratios of BK1γB\to K_1\gamma at next-to-leading order (NLO) of αs\alpha_s where K1K_1 is the orbitally excited axial vector meson. The NLO decay amplitude is divided into the vertex correction and the hard spectator interaction part. The one is proportional to the weak form factor of BK1B\to K_1 transition while the other is a convolution between light-cone distribution amplitudes and hard scattering kernel. Using the light-cone sum rule results for the form factor, we have \calB(B^0\to K_1^0(1270)\gamma)=(0.828\pm0.335)\times 10^{-5} and \calB(B^0\to K_1^0(1400)\gamma)=(0.393\pm0.151)\times 10^{-5}.Comment: 17pages, 4 figures. Minor changes, typos corrected. PRD accepted versio
    corecore