R. Szwed

Σ hypernuclear states in (K−, π±) reactions on 12C

Abstract Using negative kaons of momenta 400 and 450 MeV/c, Σ hypernuclear states have been produced in (K−, π−) and (K−, π+) reactions on 12C. The observed states are interpreted as the recoilless production of Σ particles on carbon. The upper limit for the widths of these states is estimated to be 5 MeV, independent of the charge of the Σ particle.

The (K−, π+) strangeness exchange reaction on 16O

Abstract Using negative kaons of 450 MeV/c momentum, Σ hypernuclear states have been produced in the (K−, π+) reaction on 16O. The observed states are interpreted as the recoilless production of Σ− particles in the p 3 2 and p 1 2 orbits of the Σ16C hypernucleus. Their energy splitting gives a constraint to the magnitude of the spin-orbit coupling for the Σ− particles in the nucleus.

Charged particle spectra in αα and αp collisions at the CERN ISR

Momenta of charged particles produced in inelastic αα, αp, andpp collisions were measured using the Split-Field-Magnet detector at the CERN Intersecting Storage Rings. Inclusive and semi-in-clusive spectra are presented as a function of rapidityy, Feynman-x, and transverse momentumpT. The inclusivey distributions agree well with predictions of the dual parton model; the highest particle densities are reached aty≃0 and the momenta of leading protons decrease significantly for increasing total multiplicity. ‘Temperatures’ are equal in αα, αp, andpp interactions. ThepT distributions depend weakly on the multiplicity.

Multiplicity Distributions in

Abstract The multiplicities of charged secondaries from inelastic αp and αα collisions have been measured using the Split-Field Magnet detector at the CERN Intersecting Storage Rings. Corrected multiplicity distributions for αα and αp interactions are compared with those for pp interactions and with theoretical predictions.

\alpha \alpha

Abstract Differential cross sections for αα and αp scattering have been measured at √ s =125 and 88 GeV, respectively, in the t range from −0.2 to −0.8 (GeV/ c ) 2 using the Split-Field Magnet detector at the CERN Intersecting Storage Rings. Comparison with theoretical calculations using the Glauber model confirms the importance of including inelastic shadowing effects in very high energy nucleus-nucleus elastic scattering.

and

Abstract We have measured the longitudinal ( p L ) and transverse ( p T ) momentum distributions for p, d, t, and 3 He fragments in quasi-elastic alpha-alpha collisions at √ s = 125 GeV, using the upgraded Split-Field Magnet detector at the CERN Intersecting Storage Rings. The p T distributions reflect elastic scattering among the nuclear constituents as a main mechanism. The p L distributions are only weakly perturbed by this mechanism, and reflect mainly the internal (Fermi) motion of the nuclear constituents; their widths are consistent with expectations from statistical models.

\alpha p

Two-particle rapidity correlations have been studied for αα, αp, andp p interactions at the CERN ISR using the Split-Field Magnet (SFM) detector. In order to isolate the true two-particle correlations, the analysis was performed at fixed charged multiplicity. In the framework of a simple cluster model, it is found that cluster widths as well as cluster multiplicities are the same for αα, αp, andp p interactions, and both decrease with increasing charged multiplicity.

Collisions at the {CERN} {ISR}

Abstract We present evidence for fluctuations of the average transverse momentum in pp, pα and αα collisions at ISR energies. In thermodynamical models, this is interpreted as fluctuations in the temperature of hadronic interactions. We find that the effect does not depend on the energy of the collision, however, the fluctuations are smaller for αp and αα reactions than for pp interactions.

Measurement of αα and αp elastic scattering at the CERN ISR

Abstract The inclusive production of charged hadrons has been measured in αα and αp collisions at nucleon-nucleon c.m. energies (√s nn )of 31 and 44 GeV, respectively, for transverse momenta p T up to 5 GeV/ c in the central rapidity ( y ) region. at high p T the yields are consistent with being 4 times and 16 times highere than the ones in pp interactions at y =0, for αp and αα interactions, respectively. However, an enhancement over these factors, as expected from an earlier FNAL experiment, cannot be ruled out.

Momentum distributions of nuclear fragments in αα collisions at √s = 125 GeV

AbstractProperties of secondaries associated with a high-pT charged trigger particle (3<pT<5 GeV/c) were studied for αp and αα interactions at c.m. energies