Kh. K. Olimov

Fragmentation of relativistic oxygen nuclei in interactions with a proton

Abstract.The data on investigation of inelastic interactions of 16O nuclei in a hydrogen bubble chamber at an incident momentum of 3.25 A GeV/c are presented. Separate characteristics as fragments isotope composition and topological cross-sections of fragmentation channels are given. The processes of formation of light fragments and unstable nuclei, and the break-up of the 16O nucleus into multicharge fragments are investigated. A comparison between the experimental data and the calculations of the cascade fragmentation evaporation model (CFEM) is made. The observed singularities of the interactions point out the important role of the nucleus α-cluster structure in the formation of the final products.

Comparison of characteristics of Δ0(1232) produced in p12C and d12C collisions at 4.2 A GeV/c

Reconstructed momentum, transverse momentum, kinetic energy, rapidity, and emission angle distributions along with their mean values were compared for Δ0(1232) resonances produced in p12C and d12C collisions at 4.2 A GeV/c. Mean momentum, transverse momentum, and rapidity of protons and negative pions coming from Δ0(1232) decay were extracted and compared with the corresponding mean values for protons and π− mesons in experiment and the relevant model calculations.

On spectral temperatures of negative pions produced in d 12 C, 4 He 12 C, and 12 C 12 C collisions at 4.2 A GeV/ c

The experimental transverse momentum distributions of negative pions produced in d12C, 4He12C, and 12C12C collisions at 4.2 A GeV/c were analyzed in the framework of Hagedorn Thermodynamic Model. The spectral temperatures of π− mesons as well as their relative contributions to the total multiplicity of π− mesons were extracted from fitting the pt spectra by two-temperature Hagedorn function. The results were compared systematically with the earlier results obtained from analysis of non-invariant center-of-mass energy spectra of negative pions produced in the analyzed collisions.

Correlation effects in the production of 3He nuclei in 16Op collisions at a momentum of 3.25 GeV/c per nucleon

New experimental data on the dependence of the mean multiplicities and kinematical features of 3He nuclei produced in 16Op collisions at a momentum of 3.25 GeV/c per nucleon on the degree of excitation of the fragmenting nucleus are presented. Strong correlations between the multiplicities of negatively charged pions and 3He nuclei are found.

Production of multibaryon clusters in hadron-nucleus collisions at high energies

The results obtained by analyzing the production of multibaryon clusters in π−C and p20Ne interactions at momenta of 40 and 300 GeV/c, respectively, are presented.

Spectral temperatures of Δ0(1232) resonances produced in p12C and d12C collisions at 4.2 GeV/c per nucleon

The reconstructed experimental transverse momentum (pt) distributions of Δ0(1232) resonances produced in p12C and d12C collisions at 4.2 A GeV/c and the corresponding spectra calculated using Modified FRITIOF model were analyzed in the framework of Hagedorn Thermodynamic Model. The spectral temperatures of Δ0(1232) resonances were extracted from fitting their pt spectra with one-temperature Hagedorn function. The extracted spectral temperatures of Δ0(1232) were compared with the corresponding temperatures of π− mesons in p12C and d12C collisions at 4.2 A GeV/c obtained similarly from fitting the pt spectra of π− by one-temperature Hagedorn function. The spectral temperatures of Δ0(1232) resonances agreed within uncertainties with the corresponding temperatures of π− mesons produced in p12C and d12C collisions at 4.2 A GeV/c.

Production of {delta}{sup 0} and {delta}{sup ++} resonances in collisions of {sup 4}He nuclei with carbon nuclei at 4.2 GeV/c per nucleon

In conditions of 4{pi}-geometry, the production of {delta}{sup 0} and {delta}{sup ++} resonances in collisions of {sup 4}He nuclei with carbon nuclei at 4.2 GeV/c per nucleon was investigated for the first time. The masses and widths of resonances were obtained based on an analysis of the experimental and background invariant mass distributions of p{pi}{sup {+-}} pairs. The contributions to the pion production from decays of {delta} resonances, as well as from direct pion creation, and the relative number of nucleons excited to {delta}{sup 0} at freeze-out were estimated. The results obtained were compared to the corresponding data for C+C collisions at the same initial momentum 4.2 GeV/c per nucleon.

Production of baryon resonances in {pi}{sup -}+ {sup 12}C interactions at 40 GeV/c

In conditions of 4{pi}-geometry, the production of {delta}{sup ++} and {delta}{sup 0} resonances in {pi}{sup -}+ {sup 12}C interactions at 40 GeV/c was investigated for the first time. The masses and widths of resonances were obtained from an analysis of the experimental and background invariant mass distributions of p{pi}{sup {+-}} pairs. The fractions of charged pions coming from {delta}{sup ++} and {delta}{sup 0} decay as well as the inclusive cross-section of {delta}{sup ++} and {delta}{sup 0} production were determined. The results obtained were compared to the recent results on {delta}(1232) production in {sup 4}He +C and C+C collisions at 4.2 GeV/c per nucleon, and Ni+Ni and Au+Au collisions at energies between 1 and 2A GeV.