122039401
Long-range correlations in hadron-nucleus interactions
An analysis of correlations in rapidity of charged particles produced in proton and antiproton interactions on hydrogen, argon and xenon at 200 GeV is presented. Positive long-range correlations are observed in interactions on heavy targets. The dependence of rapidity correlations between the forward and backward hemisphere on the number of projectile collisions is discussed.
188188770
The reaction k+ d ---> k0 p p at 4.6 gev/c
117777421
sigma- Production and decay properties in K-p --> sigma-pi+
123564276
Production of K∗(892) in K+N interactions at 3 GeV/c
We have studied the reactions K+d→K+π−pp,K+d→Koπopp,K+d→Koπ+pp, obtained from an exposure of the Saclay 81-cm bubble chamber filled with deuterium and exposed at CERN to a separated 3 GeV/c K+ beam. 
 
In reactions (1) and (2) there is abundant production of K∗0(892) and some production of K∗(1420). From the density matrix elements, it is found that K∗0(892) is produced mainly by pion exchange. The K∗(892) four-momentum-transfer distribution in reaction (1) agrees with the predictions of the OPE model, as modified by Durr and Pilkuhn. A marked asymmetry of the decay distribution of the K+π− system is observed and discussed in the framework of a unitarized Veneziano model. In reaction (3), on the other hand, the production of K∗+(892) and N∗+(1236) is found to proceed mainly by vector exchange.
118814310
Thermal, chemical and spectral equilibration in heavy-ion collisions
Abstract We have considered the equilibration in relativistic heavy ion collisions at energies 1–7 A GeV using our transport model. We applied periodic boundary conditions to close the system in a box. We found that the thermal equilibration takes place in the first 20–40 fm/ c whose time is comparable to the duration of a heavy ion collision. The chemical equilibration is a much slower process and the system does not equilibrate in a heavy ion collision. We have shown that in the testparticle simulation of the Boltzmann equation the mass spectra of broad resonances follow instantaneously their in-medium spectral functions as expected from the Markovian approximation to the Kadanoff–Baym equations employed via the (local) gradient expansion.
123071989
Subthreshold $\phi$ meson production in heavy-ion collisions
Within a BUU type transport model we study Φ meson production in subthreshold Ni + Ni and Ru + Ru reactions. For the first time we included in our model the elementary reaction channels ρ + N, Δ → Φ + N, π + N((1520) → Φ + N and πρ → Φ. In spite of a substantial increase of the Φ multiplicities by these channels, our results stay significantly below the preliminary experimental data.
120076285
Vector mesons in nuclear matter
We present a relativistic and unitary approach to pion- and photonnucleon scattering taking into account the πN, ρN, щN, хN, πΔ, KΛ and KΣ channels. Our scheme dynamically generates the s- and d-wave baryon resonances N (1535), N (1650), N (1520) and N (1700) and as well as Δ (1620) and Δ (1700) in terms of quasi-local two-body interaction terms. We obtain a fair description of the experimental data relevant for the properties of slow vector mesons in nuclear matter. The resulting s-wave ρ- and ω-meson nucleon scattering amplitudes, which define the leading density modification of the ρ-and ω-meson spectral functions in nuclear matter, are presented.
119042006
Scattering of vector mesons off nucleons
We construct a relativistic and unitary approach to 'high' energy pion- and photon-nucleon reactions taking the $\pi N, \pi \Delta$, $\rho N$, $\omega N$, $\eta N, K \Lambda, K \Sigma$ final states into account. Our scheme dynamically generates the s- and d-wave nucleon resonances N(1535), N(1650) and N(1520) and isobar resonances $\Delta(1620)$ and $\Delta(1700)$ in terms of quasi-local interaction vertices. The description of photon-induced processes is based on a generalized vector-meson dominance assumption which directly relates the electromagnetic quasi-local 4-point interaction vertices to the corresponding vertices involving the $\rho$ and $\omega$ fields. We obtain a satisfactory description of the elastic and inelastic pion- and photon-nucleon scattering data in the channels considered. The resulting s-wave $\rho$- and $\omega$-nucleon scattering amplitudes are presented. Using these amplitudes we compute the leading density modification of the $\rho$ and $\omega$ energy distributions in nuclear matter. We find a repulsive energy shift for the $\omega $ meson at small nuclear density but predict considerable strength in resonance-hole like $\omega$-meson modes. Compared to previous calculations our result for the $\rho$-meson spectral function shows a significantly smaller in-medium effect. This reflects a fairly small coupling strength of the N(1520) resonance to the $\rho N$ channel.
56157029
Zero temperature properties of mesons in a vector meson extended linear sigma model
A three flavor linear sigma model with vector and axial-vector mesons is discussed. Preliminary results concerning on the symmetry breaking pattern, the question of parameterization, as well as the resulting meson masses are presented.