Jet Quenching via Jet Collimation

Understand

The ATLAS Collaboration recently reported strong modifications of dijet properties in heavy ion collisions.

• In this work, we discuss to what extent these first data constrain already the microscopic mechanism underlying jet quenching.
• Simple kinematic arguments lead us to identify a frequency collimation mechanism via which the medium efficiently trims away the soft components of the jet parton shower.
• Through this mechanism, the observed dijet asymmetry can be accomodated with values of $\hat{q}\, L$ that lie in the expected order of magnitude.