The sound produced by a fast parton in the quark-gluon plasma is a "crescendo"

Understand

We calculate the total energy deposited into the medium per unit length by fast partons traversing a quark-gluon plasma.

• The medium excitation due to collisions is taken to be given by the well known expression for the collisional drag force.
• The radiative energy loss of the parton contributes to the energy deposition because each radiated gluon acts as an additional source of collisional energy loss in the medium.
• We derive a differential equation which governs how the spectrum of radiated gluons is modified when this energy loss is taken into account.