Precise determination of alpha(s) from the C-parameter distribution

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

We present a global fit for alpha(s)(m(Z)), analyzing the available C-parameter data measured at center-of-mass energies between Q = 35 and 207 GeV. The experimental data is compared to a (NLL)-L-3' + O(alpha(3)(s)) + Omega(1) theoretical prediction (up to the missing four-loop cusp anomalous dimension), which includes power corrections coming from a field-theoretical nonperturbative soft function. The dominant hadronic parameter is its first moment Omega(1), which is defined in a scheme which eliminates the O(Lambda(QCD)) renormalon ambiguity. The resummation region plays a dominant role in the C-parameter spectrum, and in this region a fit for alpha(s)(m(Z)) and Omega(1) is sufficient. We find alpha(s)(m(Z)) = 0.1123 +/- 0.0015 and Omega(1) = 0.421 +/- 0.063 GeV with chi(2)/d.o.f. = 0.988 for 404 bins of data. These results agree with the prediction of universality for Omega(1) between thrust and C-parameter within 1-sigma.

Organisation(s)
Particle Physics
External organisation(s)
Massachusetts Institute of Technology
Journal
Physical Review D
Volume
91
No. of pages
24
ISSN
1550-7998
DOI
https://doi.org/10.1103/PhysRevD.91.094018
Publication date
05-2015
Peer reviewed
Yes
Austrian Fields of Science 2012
103034 Particle physics
Keywords
Portal url
https://ucris.univie.ac.at/portal/en/publications/precise-determination-of-alphas-from-the-cparameter-distribution(560acb2c-bf3a-4b6d-a46f-4cc5d6395a23).html