C-parameter distribution at N3LL' including power corrections

Author(s)
Andre H. Hoang, Daniel W. Kolodrubetz, Vicent Mateu Barreda, Iain W. Stewart
Abstract

We compute the e+e- C-parameter distribution using the soft-collinear effective theory with a resummation to next-to-next-to-next-to-leading-log prime accuracy of the most singular partonic terms. This includes the known fixed-order QCD results up to O(αs3), a numerical determination of the two-loop nonlogarithmic term of the soft function, and all logarithmic terms in the jet and soft functions up to three loops. Our result holds for C in the peak, tail, and far tail regions. Additionally, we treat hadronization effects using a field theoretic nonperturbative soft function, with moments Ωn. To eliminate an O(ΛQCD) renormalon ambiguity in the soft function, we switch from the MS¯ to a short distance "Rgap" scheme to define the leading power correction parameter Ω1. We show how to simultaneously account for running effects in Ω1 due to renormalon subtractions and hadron-mass effects, enabling power correction universality between C-parameter and thrust to be tested in our setup. We discuss in detail the impact of resummation and renormalon subtractions on the convergence. In the relevant fit region for αs(mZ) and Ω1, the perturbative uncertainty in our cross section is 2.5% at Q=mZ.

Organisation(s)
Particle Physics, Research Platform Erwin Schrödinger International Institute for Mathematics and Physics
External organisation(s)
Massachusetts Institute of Technology
Journal
Physical Review D
Volume
91
No. of pages
35
ISSN
1550-7998
Publication date
05-2015
Peer reviewed
Yes
Austrian Fields of Science 2012
103034 Particle physics
Keywords
ASJC Scopus subject areas
Nuclear and High Energy Physics, Physics and Astronomy (miscellaneous)
Portal url
https://ucris.univie.ac.at/portal/en/publications/cparameter-distribution-at-n3ll-including-power-corrections(d4b1386e-422c-41c1-97bb-f635f3fcef93).html