Speaker
Dr
Duff Neill
(LANL)
Description
Fragmentation is a fundamental probe of the transition between the perturbative description of QCD and the non-perturbative regime. One would like to understand how the partonic quantum numbers, flavor, spin, charge, and momentum, are transported to the hadronic final state. Of utmost importance is simply the conversion of the momentum of a parton into the momentum carried by the observed hadron, in particular its three dimensional distribution inside a jet. Traditional definitions of jet axes, such as the thrust axis in e^+e^- collisions, introduce a soft sensitivity such that the transverse momentum of the hadron receives an non-negligible contribution from the soft underyling event, making comparisons between fragmentation with transverse momentum measured in hadron-hadron, hadron-electron, or e^+e^- fraught with uncontrolled contributions from factorization breaking effects and/or non-global logarithms. I will show how by a simple change in the definition of the jet axis, one can eliminate these complications, giving a transverse momentum spectrum purely determined by collinear splittings. I will also briefly consider applications of this new observable.
Primary author
Dr
Duff Neill
(LANL)
