Speaker
Description
Experimentalists and theorists are pushing towards studying large radius jets in heavy ion collisions in an endeavour to decode signs of induced radiation and medium response with increasing precision. However, even at mid-rapidity, jets are not entirely composed of final state emissions, but contain a varying amount of initial state radiation. This contribution is small for small radius jets, but increases with jet radius and can become sizeable for large radius jets. I study in detail the contributions from initial state radiation to different jet substructure observables in p+p and A+A collisions, and show how they can compromise the interpretation of these observables in heavy ion collisions in terms of medium effects. This is done with an extended version of JEWEL, in which partons emitted from the initial state parton shower interact in the background medium in the same way as final state partons.