On the Entropy of Jets

Sammanfattning: High energy particle collisions often produce large numbers of partons in the final state, which are clustered together in collimated sprays called jets. A recent paper [1] introduces the concept of jet entropy, which is an observable that quantifies the entanglement between the resolved and unresolved parts of a jet. We derive an analytic expression for the entropy of a gluon jet and compare the result to that of a simple event generator. Our results show that jet entropy is sensitive to the treatment of recoil, which suggests a novel way of testing recoil prescriptions against experimental data. We also examine models of graviton jets where the splitting functions are obtained by removing collinear pieces from gluon splitting functions, and find that the entropy depends strongly on how the collinear pieces are removed.