Results 141 to 150 of about 630 (179)

Review of lattice results concerning low-energy particle physics. [PDF]

open access: yesEur Phys J C Part Fields, 2014
FLAG Working Group   +28 more
europepmc   +1 more source

Nuclear-bound quarkonium

Physical Review Letters, 1990
We show that the QCD van der Waals interaction due to multiple gluon exchange provides a new kind of attractive nuclear force capable of binding heavy quarkonia to nuclei. The parameters of the potential are estimated by identifying multigluon exchange with the Pomeron contributions to elastic meson-nucleon scattering.
, Brodsky, , Schmidt, , de Téramond GF
openaire   +2 more sources

Mixtures of quarkonium and gluonium

Physical Review D, 1985
We study the 2\ensuremath{\gamma} decays of the light pseudoscalar mesons in a model that allows the isoscalar states to have a significant gluonium component, and show that the rates are in good agreement with experiment. The amount of radial mixing in \ensuremath{\eta},\ensuremath{\eta}' states determines these decays completely.
, Frank, , O'Donnell
openaire   +2 more sources

Nonsingular quarkonium potential

Physical Review D, 1987
It is shown that the appearance of singular terms in the quasistatic potential models of quarkonium can be avoided with the use of an improved quasistatic approximation, which yields a nonsingular quark-antiquark potential.
openaire   +2 more sources

Hyperfine splitting of quarkonium

Physical Review D, 1985
Using a QCD-motivated model we show that (M( /sup 3/S/sub 1/))/sup 2/-(M( /sup 1/S/sub 0/ ))/sup 2/ is nearly constant for all quarkonium states. We find that the acceptable range of the QCD scale parameter to explain the weak quark-mass dependence of (M( /sup 3/S/sub 1/))/sup 2/-(M( /sup 1/S/sub 0/ ))/sup 2/ is ..lambda.. = 140 +- 60 MeV.
, Igi, , Ono
openaire   +2 more sources

Relativistic description of quarkonium

Physical Review D, 1987
A relativistic (four-spinor) model Hamiltonian for quarkonium is proposed in the context of the two-particle Dirac equation. Identification of the usual linear potential as an effective mass leads to a very successful global description of quarkonium as characterized by the spectrum of meson states.
openaire   +2 more sources

Cosmic Production of Quarkonium?

Physical Review Letters, 1986
It has been suggested that pair annihilation of heavy Majorana fermions in the galactic halo into quarkonium plus a monochromatic photon could occur at an observable rate. Here we show that a calculation of Srednicki, Theisen, and Silk seriously overestimates the rate for this process, by an ordre of magnitude or more, as a result of neglecting the ...
openaire   +2 more sources

Quarkonium annihilation rates

Physical Review D, 1988
Recent measurements of ratios of quarkonium annihilation rates are used to evaluate the strong fine-structure constant ${\ensuremath{\alpha}}_{s}$. Expressions are presented for QCD radiative corrections with ${\ensuremath{\alpha}}_{s}$ referred to the quark-mass scale.
, Kwong   +3 more
openaire   +2 more sources

Relativistic quarkonium dynamics

Physical Review D, 1986
We present, in the framework of relativistic quantum mechanics of two interacting particles, a general model for quarkonium systems satisfying the following four requirements: confinement, spontaneous breakdown of chiral symmetry, soft explicit chiral-symmetry breaking, short-distance interactions of the vector type.
openaire   +2 more sources

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