N.S. Glagoleva

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.

A Study of the production and lifetime of the lightest relativistic hypernuclei

Abstract All results on the production cross sections of the lightest hypernuclei and the lifetimes of the hydrogen hypernuclei obtained in Dubna streamer chamber experiments are presented.

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

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

\bar \Lambda /\Lambda

THE GIBS MAGNETIC SPECTROMETER

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.

Pion momentum spectra in nuclear charge exchange reactions A (t, He-3)

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.

Study of the Mg(t,He-3) reaction at 9.15-GeV/c in the Delta-excitation region with a streamer chamber

Abstract The charge exchange reaction (t, 3 He) on carbon and magnesium targets is investigated in experiments using a streamer chamber. The experimental pion longitudinal momentum spectrum is compared with the calculated one for events with a single secondary pion. From this comparison it follows that the contribution from quasi-free Δ − excitation in the target nucleus in a single pion channel is only 60–70%. The momentum of the pions in the remaining fraction of events is significantly higher than that of the pions produced in delta de-excitation. The contribution from several possible processes is analyzed. The data indicate a significant role of coherent pion production via N(1440) or/and N(1520) in the target nucleus while part of the pion spectrum can be explained by projectile excitation.