Abstract. The γγ → ππ reactions are discussed. To describe those processes, we include dipion continuum, resonances, high-energy pion-pion rescatterings, ρ meson exchange and pQCD Brodsky-Lepage mechanisms. The cross section for the production of pion pairs in photon-photon collisions in peripheral heavy ion collisions is calculated with the help of Equivalent Photon Approximaption (EPA) in the...

Transport simulations including in-medium properties derived in a microscopic π+NN−1+ ∆N−1 model in infinite nuclear matter are presented. In-medium pion dispersion relations, partial ∆ decay widths, pion absorption cross sections and ∆ cross sections are incorporated into the transport description by means of a local-density approximation. Strong modifications of π and ∆ production and absorpt...

purpose: to present a case of herpes zoster ophthalmicus (hzo) with consequent posterior ischemic optic neuropathy (pion). case report: a 58-year-old woman with a history of hzo in her right eye which was under treatment presented with loss of vision to no light perception. on examination, positive relative afferent pupillary defect was detected; however the optic disc was normal on ophthalmosc...

Neutrino-induced charged current single charged pion production (CC-1π) is dominated by baryonic resonance excitation off a single nucleon bound in a nucleus in the neutrino energy region of a few GeV. The resonance state is followed by its prompt decay into a nucleon and a pion in the final state. The process is written as νμN → μ Nπ, where N is proton or neutron. In addition to this reaction,...

We describe the present status of the pion distribution amplitude as originated from two sources: (i) a nonperturbative approach, based on QCD sum rules with nonlocal condensates, and (ii) a NLO QCD analysis of the CLEO data on Fγγ ∗π(Q2), supplemented by the E791 data on diffractive dijet production, and the JLab F(pi) data on the pion electromagnetic form factor. 1. PION DISTRIBUTION AMPLITUD...