G. Pancheri

Intermediate vector meson contributions to V0→P0P0γ decays

Abstract The contribution of intermediate vector mesons to the decays V 0 →P 0 P 0 γ is calculated and compared with experimental upper limits, whenever available, and previous estimates. For some decays, like φ or ω→π 0 π 0 γ our results update the existing numbers and suggest the feasibility of their experimental detection. For the decays φ→K 0 K 0 γ and φ, ω→π 0 ηγ, we find values different from the ones in the literature and discuss the origin of the discrepancy.

Chiral perturbation theory and radiative V0→P0P0γ decays

Abstract An attempt to extend chiral perturbation theory to radiative vector meson decays into two neutral pseudoscalars, V 0 →P 0 P 0 γ , is presented. The effects of (chiral) loops are found to be important. Unambiguous predictions are given for φ → π 0 π 0 γ , π 0 ηγ , ϱ → π 0 π 0 γ and other processes to be measured in proposed low-energy e + e − machines.

Soft gluon radiation and energy dependence of total hadronic cross-sections

An impact parameter representation for soft gluon radiation is applied to obtain both the initial decrease of the total cross section

Radiative vector meson decays in SU(3) broken effective chiral Lagrangians

sigma_{tot}

Hadronic Total Cross-sections Through Soft Gluon Summation in Impact Parameter Space

for proton-proton collisions as well as the later rise of

Scalar f 0 (980) and \(\sigma (500)\) meson exchange in \(\phi\) decays into \(\pi^0\pi^0\gamma\)

sigma_{tot}

Bloch-Nordsieck Summation and Partonic Distributions in Impact Parameter Space

with energy for both pp and

Prospects for e + e − Physics at Frascati between the φ and the ψ

pbar{p}

Elastic

. The nonperturbative soft part of the eikonal includes only limited low energy gluon emission and leads to the initial decrease in the proton-proton cross section. On the other hand, the rapid rise in the hard, perturbative jet part of the eikonal is tamed into the experimentally observed mild increase by soft gluon radiation whose maximum energy rises slowly with energy.

pp

Abstract Conventional SU (3)-breaking effects are shown to be easily introduced in the sector of effective chiral Lagrangians incorporating vector mesons and containing the VVP vertices related to the anomaly. An improved description of VPγ and Pγγ transitions is obtained.