Composite particles and entropy production in relativistic nuclear collisions

Systematics of stopping and flow in Au+ Au collisions

“…At intermediate to low incident energies, especially for E/A < 100 MeV, the literature abounds with an impressive diversity in the choice of global observables that have been used in attempts to select either narrowly constrained impact parameters (keywords 'highly exclusive' or 'ultracentral') or events of special interest (keywords 'fully equilibrated', 'fully evaporated', 'signals of phase coexistence'). The observables vary from very simple ones like proton, neutron or total charged-particle multiplicity to more specific ones as, e.g., participant proton multiplicity (N p ) [53,54], total (E T ) [55,56] or light charged particle transverse kinetic energy (E 12 ⊥ ) [57], ratio of transverseto-longitudinal kinetic energy (Erat) [58,59], degree of isotropy of momenta (R) [60,61], transverse momentum directivity (D) [62][63][64][65], longitudinal kinetic-energy fraction (E e ) [66,67], linear momentum transfer [68], total kinetic-energy loss (T KEL) [69,70], average parallel velocity (V av ) [71], midrapidity charge (Z y ) [72], total charge of Z≥2 products (Z bound ) [73,74], longitudinal component of the quadrupole moment tensor (Q zz ) [75]. Even more complex observables are those obtained from sphericity [76,77], from the kinetic energy tensor [78,80] or momentum tensor [67,81,82], the thrust (T ) [67,83,84], the deflection angle of the projectile (Θ def l ) [85], the flow angle (Θ f low ) [3,86], the location in a 'Wilczyński plot' …”

Radial Flow inAu+AuCollisions atE=(0.25−1.1Lisa1, Albergo2, Bieser3 et al. 1995Phys. Rev. Lett.Self Cite938600View full textAdd to dashboardCite

“…Directed collective flow is experimentally well-established and has been used to study the nuclear equation of state [12] . However, only a small fraction of the energy available in the center of momentum is contained in directed flow, whereas from entropy studies [13] and general energy considerations [14], one expects a large portion of the total energy to be contained in collective degrees of freedom. With the recent availability of highstatistics exclusive measurements, there are indications that a large radial component of collective flow exists in central heavy ion collisions at beam energies around 100 A MeV [9,10].…”

Rapidity distributions of Ca+Ca, Nb+Nb, Ne+Au and Au+Au at bombarding energies from 250 to 2100 MeV/nucleon

“…This decrease of the fraction of the observed charge is partly due to an increase in the multiple hit probability for the heavier systems. It has, however, been shown [16,19,28] that the fragment ratios d/p, t/p, 3'4He/p etc. increase with the mass of the system.…”

“…As a consequence a progressive fraction of the charge may be contained in intermediate mass fragments, which where, for the reactions discussed, not measured with the Plastic Ball. A comparison of a model predictions with the data should therefore be simultaneously performed for particle ratios which have been published elsewhere [16,19]. …”