@article{6eaa47a2a33242a89a34594de6d2757e,
title = "From Ji to Jaffe-Manohar orbital angular momentum in lattice QCD using a direct derivative method",
abstract = "A lattice QCD approach to quark orbital angular momentum in the proton based on generalized transverse momentum-dependent parton distributions (GTMDs) is enhanced methodologically by incorporating a direct derivative technique. This improvement removes a significant numerical bias that had been seen to afflict results of a previous study. In particular, the value obtained for Ji quark orbital angular momentum is reconciled with the one obtained independently via Ji's sum rule, validating the GMTD approach. Since GTMDs simultaneously contain information about the quark impact parameter and transverse momentum, they permit a direct evaluation of the cross product of the latter. They are defined through proton matrix elements of a quark bilocal operator containing a Wilson line; the choice in Wilson line path allows one to continuously interpolate from Ji to Jaffe-Manohar quark orbital angular momentum. The latter is seen to be significantly enhanced in magnitude compared to Ji quark orbital angular momentum, confirming previous results.",
author = "M. Engelhardt and Green, {J. R.} and N. Hasan and S. Krieg and S. Meinel and J. Negele and A. Pochinsky and S. Syritsyn",
note = "Funding Information: This work benefited from fruitful discussions with M. Burkardt, W. Detmold, R. Gupta, S. Liuti and C. Lorc{\'e}. The lattice calculations performed in this work relied on code developed by B. Musch, as well as the Chroma and Qlua software suites. R. Edwards, B. Jo{\'o} and K. Orginos provided the clover fermion ensemble, which was generated using resources provided by Extreme Science and Engineering Discovery Environment (XSEDE) (supported by National Science Foundation Grant No. ACI-1053575). Computations were performed using resources of the National Energy Research Scientific Computing Center (NERSC), a U.S. DOE Office of Science User Facility operated under Contract No. DE-AC02-05CH11231. This work was furthermore supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under Grant No. DE-FG02-96ER40965 (M. E.), Grant No. DE-SC-0011090 (J. N.), and Grant No. DE-SC0018121 (A. P.), as well as through the TMD Topical Collaboration (M. E. and J. N.); and it was also supported by the U.S. Department of Energy, Office of Science, Office of High Energy Physics under Grant No. DE-SC0009913 (S. M.). N. H. and S. K. received support from Deutsche Forschungsgemeinschaft through Grant No. SFB-TRR 55, and S. S. is supported by the U.S. National Science Foundation under CAREER Award No. PHY-1847893 and through the RHIC Physics Fellow Program of the RIKEN BNL Research Center. 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 SCOAP3.",
year = "2020",
month = oct,
day = "23",
doi = "10.1103/PhysRevD.102.074505",
language = "English (US)",
volume = "102",
journal = "Physical Review D",
issn = "2470-0010",
publisher = "American Physical Society",
number = "7",
}