We construct a model for the weak pion production off the nucleon, which in addition to the weak excitation of the ∆(1232) resonance and its subsequent decay into Nπ , it includes also some background terms required by chiral symmetry. We re-fit the CA 5 (q 2) form factor to the flux averaged νμ p → μ−pπ+ ANL q2−differential cross section data, finding a substantially smaller contribution of th...

Using a non–relativistic gluon bound–state model for glueballs (G), we compute the subprocess q q̄ → Gπ, and we therefrom derive the yield of the overall reaction p p̄ → GπX, assuming the glueball and the pion to be emitted with their transverse momenta large, opposite and approximately equal. Numerical results are presented in the form of pT spectra for various glueball candidates and their poss...

It has been argued that a strangeness enhancement in heavy ion collisions might be an indirect signal for the quark-gluon plasma [1]. This enhancement should be most easily seen in the most abundant strange particles, the kaons. Experiments at the AGS and SPS indeed found a maximum in the K/π at about 30 GeV [2]. In [3] the authors presented an excitation function of the K/π ratio at these ener...

The Dubna-Mainz-Taipei dynamical model for pion electromagnetic production, which can describe well the existing data from threshold up to 1 GeV photon lab energy, is presented and used to analyze the recent precision data in the ∆ region. We find that, within our model, the bare ∆ is almost spherical while the physical ∆ is oblate. The deformation is almost saturated by the pion cloud effects....

We calculate cross sections for coherent pion production in nuclei induced by neutrinos and antineutrinos of the electron and muon type. The analogies and differences between this process and the related ones of coherent pion production induced by photons, or the (p, n) and (3He, t) reactions are discussed. The process is one of the several ones occurring for intermediate energy neutrinos, to b...

The Gerasimov-Drell-Hearn sum rule is evaluated for the deuteron by explicit integration up to a photon energy of 550 MeV including contributions from the photodisintegration channel and from coherent and incoherent single pion production as well. The photodisintegration channel converges fast enough in this energy range and gives a large negative contribution, essentially from the 1 S 0 resona...

The π∆ production on the nucleon by real and virtual photons is discussed as initial step in a simple model approach for the two pion photoand electroproduction on the nucleon, with emphasis on nucleon resonance excitation which is of interest for new facilities like TJNAF. A calculation for π∆ channel in resonance excitation region is presented and compared to existing experimental data along ...

Specific results of the computer simulation of dilepton production from expanding pion gas created in Pb+Pb 160 GeV/n collisions are presented. Az-imuthal asymmetry of dilepton pairs in non-central collisions and interesting shape of the rapidity distribution of dilepton pairs are predicted. These results are understood on theoretical level as a consequence of momentum and space asymmetries in ...

We discuss the single-spin asymmetry in semi-inclusive DIS, ep → eπX, based on the twist-3 mechanism in the collinear factorization relevant for the pion production with the large transverse-momentum. This updates our previous study by including, in particular, the contributions induced by the novel partonic subprocesses, and allows us to derive the entire formula for the corresponding single-s...