Initial energy density of gluons produced in very-high-energy nuclear collisions

In very-high-energy nuclear collisions, the initial energy of produced gluons per unit area per unit rapidity, (dE/L²)/dη, is equal to f (g²μL)(g²μ)3/g², where μ² is proportional to the gluon density per unit area of the colliding nuclei. For an SU(2) gauge theory, a nonperturbative computation of f (g²μL) shows that it varies rapidly for small g 2 μ L but varies only by ∼ 25 %, from 0.208 ± 0.004 to 0.257 ± 0.005, for a wide range 35.36-296.98 in g² μ L . This includes the range relevant for collisions at the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC). Extrapolating to SU(3), we estimate d E/dη for Au-Au collisions in the central region at RHIC and LHC.