@article{40a728f0b8d54c469aa4fcee2c2f39fc,
title = "Covariant calculation of a two-loop test of nonrelativistic QCD factorization",
abstract = "We test the nonrelativistic QCD factorization conjecture for inclusive quarkonium production at two loops by carrying out a covariant calculation of the nonrelativistic quantum chromodynamics (NRQCD) long-distance matrix element (LDME) for a heavy-quark pair in an S-wave, color-octet state to fragment into a heavy-quark pair in a color-singlet state of arbitrary orbital angular momentum. The NRQCD factorization conjecture for the universality of the LDME requires that infrared divergences that it contains be independent of the direction of the Wilson line that appears in its definition. We find this to be the case in our calculation. The results of our calculation differ in some respects from those of a previous calculation that was carried out by Nayak, Qiu, and Sterman using light-cone methods. We have identified the sources of some of these differences. The results of both calculations are consistent with the NRQCD factorization conjecture. However, the general principle that underlies this confirmation of NRQCD factorization at two-loop order has yet to be revealed.",
author = "Bodwin, {Geoffrey T.} and Chung, {Hee Sok} and Ee, {June Haak} and Kim, {U. Rae} and Jungil Lee",
note = "Funding Information: We thank Jianwei Qiu and George Sterman for many helpful discussions. The work of G. T. B. is supported by the U.S. Department of Energy, Division of High Energy Physics, under Contract No. DE-AC02-06CH11357. The work of H. S. C. at C. E. R. N. is supported by the Korean Research Foundation (KRF) through the CERN-Korea fellowship program. The work of J.-H. E. and J. L. is supported by the National Research Foundation of Korea (NRF) under Contracts No. NRF-2017R1E1A1A01074699 and No. NRF-2020R1A2C3009918. The work of U-R. K. is supported by the National Research Foundation of Korea (NRF) under Contract No. NRF-2019R1A6A3A01096460. The submitted manuscript has been created in part by UChicago Argonne, LLC, Operator of Argonne National Laboratory. Argonne, a U.S. Department of Energy Office of Science laboratory, is operated under Contract No. DE-AC02-06CH11357. The U.S. Government retains for itself, and others acting on its behalf, a paid-up nonexclusive, irrevocable worldwide license in said article to reproduce, prepare derivative works, distribute copies to the public, and perform publicly and display publicly, by or on behalf of the Government. Publisher Copyright: {\textcopyright} 2020 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the {"}https://creativecommons.org/licenses/by/4.0/{"} Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP ",
year = "2020",
month = may,
day = "1",
doi = "10.1103/PhysRevD.101.096011",
language = "English",
volume = "101",
journal = "Physical Review D",
issn = "2470-0010",
publisher = "American Physical Society",
number = "9",
}