Compression Effects in Relativistic Nucleus-Nucleus Collisions

Abstract

The negative-pion multiplicity is measured for central collisions of 40 Ar with KC1 at eight energies from 0.36 to 1.8 GeV/nucleon and for 4 He on KC1 and 40 Ar on Bal 2 at 977 and 772 MeV/nucleon, respectively. A systematic discrepancy with a cascade-model calculation which fits proton-and pion-nucleus cross sections but omits potential-energy effects is used to derive the energy going into bulk compression of the system. A value of the incompressibility constant of if =240 MeV is extracted in a parabolic form of the nuclear-matter equation of state.

Azimuthal correlations of pions in relativistic heavy-ion collisions at 1 GeV/nucleon

“…The pion multiplicity was one of the first observables suggested to be sensitive to the nuclear equation of state [10][11][12]. This was motivating a strong experimental effort (4π analysis of streamer chamber events at the BEVALAC) [13][14][15]. However, the sensitivity of pion yields and spectra [16] on the equation of state is not very high [17,18] and therefore the attention shifted towards subthreshold production of mesons (e.g.…”

Neutron matter properties in an extended Brueckner approach

“…The present situation is however rather confuse. To describe it very shortly, conventional analysis of giant monopole in nuclei [1,2], early analysis of heavy-ion collisions neglecting effective mass effects [3,4] and microscopic calculations based on potential models, be them performed in a variational [5] or in a (nonrelativistic [6] or relativistic [7]) perturbative scheme, seem to point to a so-called stiff nuclear matter equation of state, i.e. a sharp increase of the binding energy per particle between P0 and ,-~4po (P0 =normal nuclear matter equilibrium density).…”

Introduction to QCD thermodynamics and the quark-gluon plasma

“…The shaded region is the empirical equation of state deduced by Stock et al [13] including several corrections [16]. It appears that the nuclear m_atter equation of state could be much stiffer at densities t"'W 2 -4p 0 than expected .from conventional nuclear theory[17J.. Of course many experimental and theoretical questions about the precise connection between the pion yields and the equation of state remain to .…”

“…We live in a nonperturbative world where the effective interactions of those bags or hadrons are strong and short range. All we know aboJit the properties of ·bulk matter formed out of hadronic constituents Recent heavy ion experiments [13][15J at the BEVALAC in LBL are beginning to extend our knowledge of W (p, T) to higher densities and temperatures using nuclear collisions in the energy range ·E,ab ,...,; 1 AGe V. . Figure 2.1: Energy per nucleon at T=O at high densities; Empirical [13][16] (shaded region) from nuclear collision data is compared to theoretical calculations [17] [18] .…”