Calculating the initial energy density in heavy ion collisions by including the finite nuclear thickness

Understand

The initial energy density produced in heavy ion collisions can be estimated with the Bjorken energy density formula after choosing a proper formation time $\tau{_{\rm F}}$.

• However, the Bjorken formula breaks down at low energies because it neglects the finite nuclear thickness.
• Here we include both the finite time duration and finite longitudinal extension of the initial energy production.
• When $\tau{_{\rm F}}$ is not too much smaller than the crossing time of the two nuclei, our results are similar to those from a previous study that only considers the finite time duration.