Jet Shapes in Hadron Collisions: Higher Orders, Resummation and Hadronization

Abstract

The jet shape is a simple measure of how widely a jet's energy is spread. At present jet shape distributions have only been calculated to leading order in perturbative QCD. In this paper we consider how much these predictions should be affected by higher order perturbative corrections, by resummation of enhanced corrections to all orders, and by (power-suppressed) non-perturbative corrections. We also show that current cone-type jet definitions are not infrared safe for final states with more than three partons. Unless this situation is rectified by using improved definitions, hadron collider experiments will never be able to study the internal properties of jets with the quantitative accuracy already achieved in $e^+e^-$ annihilation.