Izlaganje sa skupa
Vector mesons ρ, ρ ′ and ρ ′′ diffractively photo- and leptoproduced
G. Kulzinger
; Institut für Theoretische Physik der Universität Heidelberg, Philosophenweg 16, 69120 Heidelberg, Germany
Sažetak
In the framework of non-perturbative QCD, we calculate high-energy diffractive production of vector mesons ρ, ρ ′ and ρ ′′ by real and virtual photons on a nucleon. The initial photon dissociates into a qq¯-dipole and transforms into a vector meson by scattering off the nucleon which, for simplicity, is represented as quark-diquark. The relevant dipole-dipole scattering amplitude is provided by the non-perturbative model of the stochastic QCD vacuum. The wave functions result from considerations in the frame of light-front dynamics; the physical ρ ′ - and ρ ′′-mesons are assumed to be mixed states of an active 2S-excitation and some residual rest (2Dand/or hybrid state). We obtain good agreement with the experimental data and get an understanding of the markedly different π +π −-mass spectra for photoproduction and e+e –annihilation.
Ključne riječi
non-perturbative QCD; diffraction; photoproduction; photon wave function; ρ-meson; excited vector mesons; hybrid state
Hrčak ID:
305363
URI
Datum izdavanja:
1.6.1999.
Posjeta: 416 *