arXiv subjects
Publications and source records attributed to B. L. Reznik.
The rho - omega interference in the exclusive reaction pi N \to N' e+ e- is studied within a schematic model including the established baryon resonances up to 1720 MeV. Near threshold the interference can be used to separate the isoscalar part of the electromagnetic current. The role of various baryon resonances is highlighted.
Results of a combined analysis are presented for the production of $ω$ and $ϕ$ mesons in $πN$ reactions in the near-threshold region using throughoutly a conventional ''non-strange'' dynamics based on such processes which are allowed by the non-ideal $ω-ϕ$ mixing. We show that strong interferences of the $t$ (meson exchange) and $s$ and $u$ (nucleon and nucleon resonance) channels differ significantly in $ω$ and $ϕ$ production amplitudes. This leads to a decrease of the relative yields in comparison with expectations based on one-channel models with standard $ω- ϕ$ mixing. We find a strong and non-trivial difference between observables in $ω$ and $ϕ$ production reactions caused by the different role of the nucleon and nucleon resonance amplitudes. A series of predictions for the experimental study of this effect is presented.
We estimate the contribution of f_2 trajectory exchange to the central ηand η^\prime production. It is shown that secondary Reggeons may give a large contribution to processes of double diffractive meson production at high energy.
We analyze the production of $ϕ$ mesons in $πN$ and NN reactions in the near-threshold region, using throughout the conventional ``non-strange'' dynamics based on such processes which are allowed by the non-ideal $ω-ϕ$ mixing. We show that the occurrence of the direct $ϕNN$ interaction may show up in different unpolarized and polarization observables in $πN\to Nϕ$ reactions. We find a strong non-trivial difference between observables in the reactions $pp\to ppϕ$ and $pn\to pnϕ$ caused by the different role of the spin singlet and triplet states in the entrance channel. A series of predictions for the experimental study of this effect is presented.
Within a covariant effective one-boson exchange model for the $T$ matrix of $NN$ interactions we present detailed calculations of bremsstrahlung cross sections for proton - proton and proton - neutron reactions at beam energies in the 1 GeV region. Besides pure bremsstrahlung processes we consider photons from $Δ$ decays and contributions from the $η\to γγ$ process. At beam energies above 700 MeV the $Δ$ decay channel dominates the spectra at large photon energies, where the interference between non-resonance processes and the $Δ$ decay channel becomes also important. Low energy photons stem from pure bremsstrahlung processes. The available experimental data at 730 MeV beam energy is well described. We extrapolate the model down to 280 MeV, where more detailed experimental data exist, and find agreement with angular distributions.