J. Lukstins

A study of pion production in 4.5 GeV/c)/nucleon 4He interactions with nuclear targets

Abstract Inelastic interactions of 4 He nuclei at the incident momentum of 4.5 GeV/ c )/nucleon with pure Li, C, Al, Cu and Pb targets were studied in the SKM-200 streamer chamber. Cross sections and their dependence on the target mass number for fragmentation processes were obtained. The multiplicities, transverse momenta and rapidities of negative pions as well as their correlations were analyzed separately for “central” and “peripheral” collisions. A comparison of the results with the predictions of some theoretical models is presented.

Streamer chamber study of the cross sections and multiplicities in nucleus-nucleus interactions at the incident momentum of 4.5 GeV/c per nucleon

Abstract The experimental data obtained with the SKM-200 streamer chamber set-up are presented. The cross-section values and multiplicity distributions of negative secondaries in the inelastic 12 C interactions and in the central 12 C and 16 O collisions with pure nuclear targets (C, Ne, Si, Cu and Zr) are discussed. The results of this experiment and of the earlier ones concerning the 4 He-nucleus interactions at the same incident momentum of 4.5 GeV/ c are analyzed and compared with those of several other experiments and with the predictions of some theoretical models.

Characteristics of Λ andK0 particles produced in central nucleus nucleus collisions at a 4.5 GeV/c momentum per incident nucleon

AbstractData on Λs andK0s, produced in central nucleus-nucleus collisions (C−C, C−Ne, O−Ne, C−Cu, C−Zr, C−Pb, O−Pb) at a 4.5 GeV/c momentum per incident nucleon obtained in the streamer chamber spectrometer SKM-200, are presented. Multiplicities, transverse momenta, rapidities and other characteristics are considered and compared with those for inelastic He−Li interactions. The polarization of Λs was found to be consistent with zero. The upper limit of

Characteristics of π−-meson multiplicity distributions in central collisions of12C and16O with nuclei at a momentum of 4.5 GeV/c per incident nucleon

\bar \Lambda /\Lambda

A hypernuclear program for the Nuclotron accelerator

production ratio was estimated to be ≤10−2 with a 90% confidence level. The results are compared with data of other experiments and some model calculations.

Dependence of the interferometric sizes of the pion generation volume on the sizes of the pion wave packet

Abstract Using a new method of data processing in the investigation of interference correlations of identical particles, a direct proof of nonstationarity of the π − production volume in central MgMg collisions at a beam momentum of p Iab = 4.4 GeV/c per nucleon was obtained. The velocity of a source of correlated π − meson pairs is introduced as a free parameter in the Lorentz transformed approximation formula of the interference peak. This velocity increases with increasing the velocity of a subset of π − mesons which are chosen for the interference analysis. The source velocity is the new experimentally measurable physical variable of interference analysis, apart from space-time sizes of the source.

Pion production in nuclear charge exchange reactions A(t, 3He)

Multiplicities of π−-mesons from central collisions of12C and16O(4.5 GeV/c/n momentum) with several target nuclei were studied in a streamer chamber experiment. The parameter η=(〈n−2〉−〈n−〉2)/〈n−〉 was determined for several samples of events characterized by different values of Θch — the “vetoangle” for emission of the projectile charged fragments. The value of η is shown to decrease when the projectile mass number increases from 12 to 16 and to decrease significantly when Θch increases from 0° to 4°, whereas it remains nearly constant when Θch increases further to 14°. The results are compared with predictions of some theoretical models.

Readout system of TPC/MPD NICA project

Abstract Calculations of the integral cross sections of the Coulomb and diffraction interactions of hypertritons are performed. The possibilities to determine the hypertriton binding energy with a higher precision, to refine information on the Λd interaction and other details of the hypertriton structure and interaction by means of the suggested measurements are also shown.