Mass of nonrelativistic meson from leading twist distribution amplitudes

In this paper distribution amplitudes of pseudoscalar and vector nonrelativistic mesons are considered. Using equations of motion for the distribution amplitudes, it is derived relations which allow one to calculate the masses of nonrelativistic pseudoscalar and vector meson if the leading twist distribution amplitudes are known. These relations can be also rewritten as relations between the masses of nonrelativistic mesons and infinite series of QCD operators, what can be considered as an exact version of Gremm-Kapustin relation in NRQCD.Comment: 4 page

The ρ\rho Meson Light-Cone Distribution Amplitudes of Leading Twist Revisited

We give a complete re-analysis of the leading twist quark-antiquark light-cone distribution amplitudes of longitudinal and transverse $\rho$ mesons. We derive Wandzura-Wilczek type relations between different distributions and update the coefficients in their conformal expansion using QCD sum rules including next-to-leading order radiative corrections. We find that the distribution amplitudes of quarks inside longitudinally and transversely polarized $\rho$ mesons have a similar shape, which is in contradiction to previous analyses.Comment: 21 pages, latex2e, requires a4wide.sty and epsf.sty, 6 PS figures include

Exclusive Radiative B-Decays in the Light-Cone QCD Sum Rule Approach

We carry out a detailed study of exclusive radiative rare $B$-decays in the framework of the QCD sum rules on the light cone, which combines the traditional QCD sum rule technique with the description of final state vector mesons in terms of the light-cone wave functions of increasing twist. The decays considered are: $B_{u,d} \to K^* +\gamma, B_{u,d}\to \rho+\gamma, B_d\to \omega+\gamma$ and the corresponding decays of the $B_s$ mesons, $B_s\to \phi+\gamma$ and $B_s\to K^*+\gamma$. Based on our estimate of the transition form factor F_1^{B \to K^*\pg}(0) =0.32\pm0.05, we find for the branching ratio $BR(B \to K^* + \gamma) = (4.8\pm 1.5)\times 10^{-5}$, which is in agreement with the observed value measured by the CLEO collaboration. We present detailed estimates for the ratios of the radiative decay form factors, which are then used to predict the rates for the exclusive radiative B-decays listed above. This in principle allows the extraction of the CKM matrix element $|V_{td}|$ from the penguin-dominated CKM-suppressed radiative decays when they are measured. We give a detailed discussion of the dependence of the form factors on the $b$-quark mass and on the momentum transfer, as well as their interrelation with the CKM-suppressed semileptonic decay form factors in $B\to \rho+\ell+\nu$, which we also calculate in our approach.Comment: 32 pages, 10 uuencoded figures, LaTeX, preprint CERN-TH 7118/9

Chiral Symmetry Breaking in Quenched Massive Strong-Coupling QED4_4

We present results from a study of subtractive renormalization of the fermion propagator Dyson-Schwinger equation (DSE) in massive strong-coupling quenched QED$_4$. Results are compared for three different fermion-photon proper vertex {\it Ans\"{a}tze\/}: bare $\gamma^\mu$, minimal Ball-Chiu, and Curtis-Pennington. The procedure is straightforward to implement and numerically stable. This is the first study in which this technique is used and it should prove useful in future DSE studies, whenever renormalization is required in numerical work.Comment: REVTEX 3.0, 15 pages plus 7 uuencoded PostScript figure

Electromagnetic Form Factors of the SU(3) Octet Baryons in the semibosonized SU(3) Nambu-Jona-Lasinio Model

The electromagnetic form factors of the SU(3) octet baryons are investigated in the semibosonized SU(3) Nambu--Jona-Lasinio model (chiral quark-soliton model). The rotational $1/N_c$ and strange quark mass corrections in linear order are taken into account. The electromagnetic charge radii of the nucleon and magnetic moments are also evaluated. It turns out that the model is in a remarkable good agreement with the experimental data.Comment: RevTex is used. 37 pages. The final version to appear in Phys. Rev. D. 13 figures are include

Interpolation Formulas for the Eta-Gamma and Eta'-Gamma Transition Form Factors

The new CLEO and LEP data on the eta-gamma and eta'-gamma transition form factors have renewed the interest in simple interpolation formulas, valid at any value of momentum transfer. We are going to show that recent theoretical and phenomenological results on eta-eta' mixing lead to two-pole forms, where each pole term resembles the Brodsky/Lepage interpolation formula for the pi-gamma case and depends on the mixing and decay parameters in a simple fashion. The parameters, entering the occasionally used one-pole formulas, on the other hand, cannot be interpreted theoretically in a simple way.Comment: 4 pages, 3 figures, using revtex, epsfig; to be published in Phys.Rev.D; hypertex dvi-file available at http://wptu38.physik.uni-wuppertal.de/~feldmann/pub/wub98_7_hyp.dv

Dynamics of Barred Galaxies

Some 30% of disc galaxies have a pronounced central bar feature in the disc plane and many more have weaker features of a similar kind. Kinematic data indicate that the bar constitutes a major non-axisymmetric component of the mass distribution and that the bar pattern tumbles rapidly about the axis normal to the disc plane. The observed motions are consistent with material within the bar streaming along highly elongated orbits aligned with the rotating major axis. A barred galaxy may also contain a spheroidal bulge at its centre, spirals in the outer disc and, less commonly, other features such as a ring or lens. Mild asymmetries in both the light and kinematics are quite common. We review the main problems presented by these complicated dynamical systems and summarize the effort so far made towards their solution, emphasizing results which appear secure. (Truncated)Comment: This old review appeared in 1993. Plain tex with macro file. 82 pages 18 figures. A pdf version with figures at full resolution (3.24MB) is available at http://www.physics.rutgers.edu/~sellwood/bar_review.pd

Measuring Polarized Gluon and Quark Distributions with Meson Photoproduction

We calculate polarization asymmetries in photoproduction of high transverse momentum mesons, focusing on charged pions, considering the direct, fragmentation, and resolved photon processes. The results at very high meson momentum measure the polarized quark distributions and are sensitive to differences among the existing models. The results at moderate meson momentum are sensitive to the polarized gluon distribution and can provide a good way to measure it. Suitable data may come as a by-product of deep inelastic experiments to measure $g_1$ or from dedicated experiments.Comment: RevTeX, 11 pages, 13 postscript figures; changes made in response to the referee's comment

Further Experimental Studies of Two-Body Radiative \Upsilon Decays

Continuing our studies of radiative Upsilon(1S) decays, we report on a search for Upsilon to gamma eta and Upsilon to gamma f_{J}(2220) in 61.3 pb^{-1} of e^{+}e^{-} data taken with the CLEO II detector at the Cornell Electron Storage Ring. For the gamma eta search the three decays of the eta meson to pi^{+}pi^{-}pi^{0}, pi^{0}pi^{0}pi^{0}, and gamma gamma were investigated. We found no candidate events in the two (3\pi)^{0} modes and no significant excess over expected backgrounds in the gamma gamma mode to set a limit on the branching fraction of B(Upsilon to gamma eta) < 2.1 x 10^{-5} at 90% C.L. The three charged two-body final states h h-bar (h = pi^{+}, K^{+}, p) were investigated for f_{J}(2220) production, with one, one, and two events found, respectively. Limits at 90% C.L. of B(\Upsilon to gamma f_{J}) x B(f_{J} to h h-bar) ~ 1.5 x 10^{-5} have been set for each of these modes. We compare our results to measurements of other radiative Upsilon decays, to measurements of radiative J/psi decays, and to theoretical predictions.Comment: 19 pages postscript, also available through http://w4.lns.cornell.edu/public/CLNS, submitted to Physical Review

Conformal symmetry on the light cone and nonleading twist distribution amplitudes of massive vector meson

A complete set of asymptotic three particle light cone distribution amplitudes of twist 3 and 4 for a transversely polarized massive vector meson built out of massless current quarks is constructed. The method used is based on a modified conformal projectors technique which allows to handle kinematical corrections due to a finite hadron mass. Consequences of our finding for the \rho -meson hard diffractive electroproduction and \gamma \rho \pi form factor are discussed. Our results may imply a breakdown of OPE for some exclusive processes beyond the leading twist level.Comment: Latex, 12 pages, no figure