Information entropy for central ^197Au+^197Au collisions in the UrQMD model

Multiplicity information entropy in central ^197Au + ^197Au collisions at impact parameters of 0-3 fm are calculated at various center of mass energies (√(s_ NN)) of 5.0, 7.7, 11.5, 14.5, 19.6, 27.0, 32.0, 35.0, 39.0, and 54.4 GeV using the Ultra-relativistic Quantum Molecular Dynamics model (UrQMD). The simulations in UrQMD model are compared with hydro modes with three different equations of state (EoS) and also with a default mode without hydrodynamics. The study reveals that the information entropies of baryons, net-baryons and net-protons with different equations of state in the hydro modes exhibit first decreases and then slowly increases with the increase of √(s_ NN), while those of hadrons and anti-hadrons, antibaryons show a monotonous increase with √(s_ NN). An enhancement is found around √(s_ NN) ∼ 30 GeV potentially corresponding to the critical endpoint with chiral hadron gas EoS and Bag model EoS.