Using hadronic Lagrangians that include the interaction of pentaquark Q+ baryon with K and N, we evaluate the cross sections for its production from meson-proton, proton-proton, and photon-proton reactions near threshold. With empirical coupling constants and form factors, the predicted cross sections are about 1.5 mb in kaon-proton reactions, 0.1 mb in r-nucleon reactions, 0.05 mb in pion-nucl...

An optical potential abrasion-ablation collision model is used to calculate hadronic dissociation cross sections for a 14.6A GeV Si beam fragmenting in aluminum, tin, and lead targets. The frictionalspectator-interaction (FSI) contributions are computed with two different formalisms for the energy-dependent mean free path. These estimates are compared with experimental data and with estimates o...

The new hadronic Monte Carlo model QGSJET-II is applied for extensive air shower (EAS) calculations. The obtained results are compared to the predictions of the original QGSJET and of the SIBYLL 2.1 interaction models. It is shown that non-linear effects change substantially model predictions for hadron-nucleus interactions and produce observable effects for calculated EAS characteristics. Fina...

The jets of microquasars with high-mass stellar companions are exposed to the dense matter field of the stellar wind. We present estimates of the gamma-ray emission expected from the jet-wind hadronic interaction and we discuss the detectability of the phenomenon at high energies. The proposed mechanism could explain some of the unidentified gamma-ray sources detected by EGRET instrument on the...

Basic physics concepts of the QGSJET model are discussed, starting from the general picture of high energy hadronic interactions and addressing in some detail the treatment of multiple scattering processes, contributions of “soft” and “semihard” parton dynamics, implementation of non-linear interaction effects. The predictions of the new model version (QGSJET II-03) are compared to selected acc...

Some years ago Marciano' speculated about the existence of exotic new species of quarks belonging to a higher representation of SU(3) in addition to the usual 3plets that are needed to describe the hadronic sector. In this case no extrastrong interaction based on an unbroken gauge group SU(N) will be introduced as in the hypercolor scenario. ' The basis of Marciano's conjecture is that the quan...

The production of dielectrons in reactions involving a1 mesons and pions is studied. We compare results obtained with different phenomenological Lagrangians that have been used in connection with hadronic matter and finite nuclei. We insist on the necessity for those interactions to satisfy known empirical properties of the strong interaction. Large off-shell effects in dielectron production ar...

A new method for making high-resolution ground-based measurements of the energy and charge of cosmic ray primaries in the region of the knee is presented. The method exploits the direct component of Cerenkov radiation emitted by cosmic ray nuclei prior to their first hadronic interaction in the atmosphere. A dedicated ground-based Direct Cerenkov detector could achieve model-independent charge ...