The effect of pion-pion scattering resonance on the isovector part of nucleon structure is analysed by a method similar to that of Frazer and Fulco, but with one more subtraction for dispersion relations on helicity amplitudes of nucleon·aritinucleon production process in order to remedy the divergence regarding the left-hand cut. If the subtracted spectral representations are used for the form...

We report the first experimental observation of the pionic fusion of two heavy ions. The 12 C(12 C, 24 Mg)π 0 and 12 C(12 C, 24 Na)π + cross sections have been measured to be 208 ± 38 and 182 ± 84 picobarns, respectively, at E cm = 137 MeV. This cross section for heavy-ion pion production, at an energy just 6 MeV above the absolute energy-conservation limit, constrains possible production mecha...

S. Bender† 1, H. Lenske1,2, and R. Shyam3 1Institut für Theoretische Physik, Universität Gießen, Germany; 2GSI, Darmstadt, Germany; 3Saha Institute of Nuclear Physics, Kolkata, India We investigated pion induced coherent strangeness production on light (C) and medium-heavy (Ca, V, Y) nuclei with a covariant model. This model was based on a Lagrangian approach, where resonance excitation and dec...

We show that a hydrodynamical model with continuous particle emission instead of sudden freeze out may explain both the observed strange particle and pion abundances and transverse mass spectra for light projectile at SPS energy. We found that the observed enhancement of pion production corresponds, within the context of continuous emission, to the maximal entropy production.

Neutrino-nucleus cross sections for the detection of atmospheric neutrinos are calculated in relativistic impulse and random phase approximations. Pion production is estimated via inclusive ∆hole nuclear excitations. The number of pion events can confuse the identification of the neutrino flavor. As a further source of pions we calculate coherent pion production (where the nucleus remains in th...

I concentrate in this article on the reaction coherent pion production by neutrinos incident on nuclei. A special effort is made in order to describe the approximations entering the calculation. I conclude that the reaction is well understood and with appropriate data for hadronic reactions it can be computed for low and high neutrino energies. Because of shortage of space I omitted the resonan...

The analyzing power of pp → ppπ 0 reaction has been measured at the beam energy of 390 MeV. The missing mass technique of final protons has been applied to identify the π 0 production event. The dependences of the analyzing power on the pion emission-angle and the relative momentum of the protons have been obtained. The angular dependence could be decomposed by the Legendre polynomial and the r...

The analyzing power of pp → ppπ 0 reaction has been measured at the beam energy of 390 MeV. The missing mass technique of final protons has been applied to identify the π 0 production event. The dependences of the analyzing power on the pion emission-angle and the relative momentum of the protons have been obtained. The angular dependence could be decomposed by the Legendre polynomial and the r...

We present a systematic analysis of next-to-next-to-leading-order diagrams that contribute to the pp → ppπ 0 production at threshold. Analytic expressions are given for the effective transition operators, and the relative importance of various types of diagrams is discussed. The vertex-correction-type graphs are found to give only small corrections to lower order graphs in conformity with expec...

The neutrino pion production off the nucleon is traditionally described in the literature by means of the weak excitation of the ∆(1232) resonance and its subsequent decay into Nπ . Here, we present results from a model that includes also some background terms required by chiral symmetry. We show that the contribution of these terms is sizeable and leads to significant effects in total and part...