An outstanding problem in QCD and jet physics is the factorization and resummation of logarithms that arise due to phase space constraints, so-called non-global logarithms (NGLs). In this paper, we show that NGLs can be factorized and resummed down to an unresolved infrared scale by making sufficiently many measurements on a jet or other restricted phase space region. Resummation is accomplished by renormalization group evolution of the objects in the factorization theorem and anomalous dimensions can be calculated to any perturbative accuracy and with any number of colors. To connect with the NGLs of more inclusive measurements, we present a novel perturbative expansion which is controlled by the volume of the allowed phase space for unresolved emissions. Arbitrary accuracy can be obtained by making more and more measurements so to resolve lower and lower scales. We find that even a minimal number of measurements produces agreement with Monte Carlo methods for leading-logarithmic resummation of NGLs at the sub-percent level over the full dynamical range relevant for the Large Hadron Collider. We also discuss other applications of our factorization theorem to soft jet dynamics and how to extend to higher-order accuracy.
Journal of High Energy Physics
- Pub Date:
- September 2015
- High Energy Physics - Phenomenology;
- High Energy Physics - Theory;
- Nuclear Theory
- 46 pages + appendices, 10 figures. v2: added current figures 4 and 5, as well as corrected several typos in appendices. v3: corrected some typos, added current figure 9, and added more discussion of fixed-order versus dressed gluon expansions. v4: fixed an error in numerics of two-dressed gluon