Multifragmentation in Collisions of 4.4gev-Deuterons with Gold Target

The relative velocity correlation function of pairs of intermediate mass fragments has been studied for d+Au collitions at 4.4 GeV. Experimental correlation functions are compared to that obtained by multibody Coulomb trajectory calculations under the assumption of various decay timees of the fragmenting system. The combined approach with the empirically modified intranuclear cascade code followed by the statistical multifragmentation model was used to generate the starting conditions for these calculations. The fragment emossion time is found to be less than 40 fm/c.Comment: Accepted for publication in Bulletin of the Russian Academy of Sciences. Physic

Critical temperature for the nuclear liquid-gas phase transition (from multifragmentation and fission)

Critical temperature Tc for the nuclear liquid-gas phase transition is stimated both from the multifragmentation and fission data. In the first case,the critical temperature is obtained by analysis of the IMF yields in p(8.1 GeV)+Au collisions within the statistical model of multifragmentation (SMM). In the second case, the experimental fission probability for excited 188Os is compared with the calculated one with Tc as a free parameter. It is concluded for both cases that the critical temperature is higher than 16 MeV.Comment: 15 pages, 8 figure

A Model of Strongly Correlated Electrons with Condensed Resonating-Valence-Bond Ground States

We propose a new exactly solvable model of strongly correlated electrons. The model is based on a $d$-$p$ model of the CuO$_2$ plane with infinitely large repulsive interactions on Cu-sites, and it contains additional correlated-hopping, pair-hopping and charge-charge interactions of electrons. For even numbers of electrons less than or equal to 2/3-filling, we construct the exact ground states of the model, all of which have the same energy and each of which is the unique ground state for a fixed electron number. It is shown that these ground states are the resonating-valence-bond states which are also regarded as condensed states in which all electrons are in a single two-electron state. We also show that the ground states exhibit off-diagonal long-range order.Comment: 17 pages, 1 figure, v2: minor changes, v3: minor changes and typos correction

Multifragmentation and nuclear phase transitions (liquid-fog and liquid-gas)

Thermal multifragmentation of hot nuclei is interpreted as the nuclear liquid-fog phase transition. The charge distributions of the intermediate mass fragments produced in p(3.6 GeV) + Au and p(8.1 GeV) + Au collisions are analyzed within the statistical multifragmentation model with the critical temperature for the nuclear liquid-gas phase transition Tc as a free parameter. The analysis presented here provides strong support for a value of Tc > 15 MeV.Comment: 4 pages, 2 figures, Submittet to Proc. of NN2003 to be published in Nucl. Phys.

Recoil Studies in the Reaction of 12-C Ions with the Enriched Isotope 118-Sn

The recoil properties of the product nuclei from the interaction of 2.2 GeV/nucleon 12-C ions from Nuclotron of the Laboratory of High Energies (LHE), Joint Institute for Nuclear Research (JINR) at Dubna with a 118-Sn target have been studied using catcher foils. The experimental data were analyzed using the mathematical formalism of the standard two-step vector model. The results for 12-C ions are compared with those for deuterons and protons. Three different Los Alamos versions of the Quark-Gluon String Model (LAQGSM) were used for comparison with our experimental data.Comment: 10 pages, 6 figures, submitted to Nucl. Phys.

Measurement of the complete nuclide production and kinetic energies of the system 136Xe + hydrogen at 1 GeV per nucleon

We present an extensive overview of production cross sections and kinetic energies for the complete set of nuclides formed in the spallation of 136Xe by protons at the incident energy of 1 GeV per nucleon. The measurement was performed in inverse kinematics at the FRagment Separator (GSI, Darmstadt). Slightly below the Businaro-Gallone point, 136Xe is the stable nuclide with the largest neutron excess. The kinematic data and cross sections collected in this work for the full nuclide production are a general benchmark for modelling the spallation process in a neutron-rich nuclear system, where fission is characterised by predominantly mass-asymmetric splits.Comment: 18 pages, 14 figure

Critical Temperature for the Nuclear Liquid-Gas Phase Transition

The charge distribution of the intermediate mass fragments produced in p (8.1 GeV) + Au collisions is analyzed in the framework of the statistical multifragmentation model with the critical temperature for the nuclear liquid-gas phase transition $T_c$ as a free parameter. It is found that $T_c=20\pm3$ MeV (90% CL).Comment: 4 pages, 3 figures, published in Phys. Rev.