ΛSpectra in11.6AGeV/cAu-Au Collisions

Abstract

E896 has measured Lambda production in 11.6A GeV/c Au-Au collisions over virtually the whole rapidity phase space. The midrapidity p(t) distributions have been measured for the first time at this energy and appear to indicate that the Lambda hyperons have different freeze-out conditions than protons. A comparison with the relativistic quantum molecular dynamics model shows that while there is good shape agreement at high rapidity the model predicts significantly different slopes of the m(t) spectra at midrapidity. The data, where overlap occurs, are consistent with previously reported measurements.

Separate mass scaling of the widths of the rapidity distributions for mesons and baryons at energies available at the Facility for Antiproton and Ion Research

“…From this figure it is also seen that lighter mesons like π − and K − show a fair agreement between experimental data [9,[13][14][15][16][17][18][19][20][21][22][23] and UrQMD prediction at all energies. However, for heavier meson like φ, as the energy of collision increases, there is a considerable disagreement between the observed and UrQMD predicted values.…”

“…In Fig. 1, the rapidity distributions of a few hadrons such as π − , k − , φ, and produced in UrQMD generated Au + Au collisions at 10, 20, 30 and 40 A GeV are plotted and compared with the existing Super Proton Synchrotron (SPS) [9,[13][14][15][16] and Alternating Gradient Synchrotron (AGS) (E802, E877, E896, E917) [17][18][19][20][21][22][23] data at the same energies. It is seen from this figure that, with UrQMD generated events, the rapidity distribution of ( + 0 ) and not alone gives a better agreement with the experimental data on .…”

“…The rapidity spectra of all the studied hadrons from UrQMD generated and experimental data [17][18][19][20][21][22][23] (AGS data) are parametrized by a sum of two Gaussian functions displaced symmetrically around midrapidity by a shift a:…”

“…(Color online) Variation of width of the rapidity distribution (calculated from data[9,[13][14][15][16][17][18][19][20][21][22][23]) of (a) mesons and (b) baryons as a function of beam rapidity in the laboratory system. (c) The same has been plotted separately for and φ.…”

Parton-hadron-quantum-molecular dynamics: A novel microscopic n -body transport approach for heavy-ion collisions, dynamical cluster formation, and hypernuclei production

“…9 and 10 the proton rapidity distributions and m T spectra for central Au+Au collisions at beam energies of 4, 6, 8 and 10.7 AGeV, calculated in PHQMD with a hard and a soft EoS. The PHQMD results are compared with those from PHSD as well as with the AGS experimental data [78][79][80][81][82][83][84]. In the rapidity spectra the influence of the EOS becomes only slightly visible at the lowest beam energy but the transverse mass spectra show a sensitivity to the EOS at all energies.…”