ar X iv : n uc l - th / 0 21 10 54 v 1 1 9 N ov 2 00 2 1 π and ρ loop corrections to ω photoproduction in the resonance region

ar X iv : n uc l - th / 9 80 30 15 v 1 5 M ar 1 99 8 ω and ρ Photoproduction with an Effective Quark Model Lagrangian

An unified approach for vector meson photoproduction is presented in the constituent quark model. The sand u-channel resonance contributions are generated using an effective quark vector-meson Lagrangian. In addition, taking into account π and σ t-channel exchanges for diffractive production, the available total and differential cross section data for ω, ρ, ρ, and ρ− photoproduction can be well...

ar X iv : n uc l - th / 0 21 10 85 v 1 2 7 N ov 2 00 2 1 Medium effects to the N ( 1535 ) resonance and η mesic nuclei

ar X iv : n uc l - th / 0 30 30 44 v 1 1 8 M ar 2 00 3 Photoproduction of η ′ - mesons from the Proton

The presently available data for the reaction γp→η ′ p are analyzed in terms of a model in which the dominant production mechanism is the exchange of the vector mesons ω and ρ. To describe the data at photon energies close to the production threshold we introduce a resonance contribution due to the well established S 11 (1535) resonance. Finally we study the contributions due to nucleon exchang...

ar X iv : n uc l - th / 9 71 10 54 v 1 2 6 N ov 1 99 7 The π + – emission puzzle in 4 Λ He decay

We re-examine the puzzling π emission from the weak decay of 4ΛHe and propose an explanation in terms of a three–body decay of the virtual Σ. Such a resolution of the π decay puzzle is consistent with the calculated Σ probability in light Λ hypernuclei as well as the experimentally observed π energy spectrum and s–wave angular distribution. Typeset using REVTEX

ar X iv : n uc l - th / 0 20 70 52 v 1 1 6 Ju l 2 00 2 Photoproduction of the η Meson from the Deuteron Near Threshold ∗

Very recent data for the reaction γd→ηnp are analyzed within a model that includes contributions from the impulse approximation and next order corrections due to the np and ηN interactions in the final state. Comparison between the calculations and data indicate sizable contributions from the np and ηN final state interactions close to threshold.