Hard Matching for Boosted Tops at Two Loops

Author(s)
André H. Hoang, Aditya Pathak, Piotr Pietrulewicz, Iain W. Stewart
Abstract

Cross sections for top quarks provide very interesting physics opportunities, being both sensitive to new physics and also perturbatively tractable due to the large top quark mass. Rigorous factorization theorems for top cross sections can be derived in several kinematic scenarios, including the boosted regime in the peak region that we consider here. In the context of the corresponding factorization theorem for e+e− collisions we extract the last missing ingredient that is needed to evaluate the cross section differential in the jet-mass at two-loop order, namely the matching coefficient at the scale μ≃mt. Our extraction also yields the final ingredients needed to carry out logarithmic resummation at next-to-next-to-leading logarithmic order (or N3LL if we ignore the missing 4-loop cusp anomalous dimension). This coefficient exhibits an amplitude level rapidity logarithm starting at (α2s) due to virtual top quark loops, which we treat using rapidity renormalization group (RG) evolution. Interestingly, this rapidity RG evolution appears in the matching coefficient between two effective theories around the heavy quark mass scale μ≃mt.

Organisation(s)
Particle Physics
External organisation(s)
Massachusetts Institute of Technology, Deutsches Elektronen-Synchrotron DESY
Journal
Journal of High Energy Physics
Volume
2015
No. of pages
36
ISSN
1029-8479
Publication date
12-2015
Peer reviewed
Yes
Austrian Fields of Science 2012
103012 High energy physics
Keywords
Portal url
https://ucris.univie.ac.at/portal/en/publications/hard-matching-for-boosted-tops-at-two-loops(4badfe24-4bd9-4890-b452-27bd1879dfb8).html