High baryon densities in heavy ion collisions at energies attainable at the BNL Relativistic Heavy-Ion Collider and the CERN Large Hadron Collider

Abstract

In very high energy collisions nuclei are practically transparent to each other but produce very hot, nearly baryon-free, matter in the so-called central rapidity region. The energy in the central rapidity region comes from the kinetic energy of the colliding nuclei. We calculate the energy and rapidity loss of the nuclei using the color glass condensate model. This model also predicts the excitation energy of the nuclear fragments. Using a space-time picture of the collision we calculate the baryon and energy densities of the receding baryonic fireballs. For central collisions of gold nuclei at the highest energy attainable at the Relativistic Heavy Ion Collider, for example, we find baryon densities more than ten times that of atomic nuclei over a large volume.

Dynamical initial-state model for relativistic heavy-ion collisions

“…where σ is the string tension. A similar prescription with the constant string tension replaced by space and time dependent components of the energy momentum tensor of the Glasma was introduced in [26]. That framework is however likely constrained to high (i.e.…”

Longitudinal dynamics of high baryon density matter in high-energy heavy-ion collisions

“…A full 3+1D numerical computation of Eqs. (1) and (3) with high baryon density initial conditions are challenging [28]. Instead, we focus on the 1+1D (tem-poral+longitudinal) situation and study the longitudinal dynamics of the high baryon density matter, given the initial conditions.…”

“…Most of the baryons are carried away by the nuclear remnants and are located in the so-called fragmentation regions. In previous papers [1,2], it has been argued that very high baryon densities, more than ten times larger than the normal nuclear density, can be achieved in these fragmentation regions. In this paper, we assume the high baryon density matter is thermalized at the same time as the baryon-free quark-gluon plasma in the central rapidity region.…”

Strange fireball as an explanation of the muon excess in Auger data

“…Interestingly, the lattice-QCD calculation converges towards the quark-hadron crossover line as µ B → 0 [107,108], but it appears to depart from this line at large values of µ B [109]. This a widely discussed feature [110][111][112][113][114] which has, however, not been conclusively understood. (Several hadronization schemes have been proposed, see e.g.…”