Title: Nucleon transverse momentum-dependent parton distributions in lattice QCD: Renormalization patterns and discretization effects

Abstract

Lattice QCD calculations of transverse momentum-dependent parton distribution functions (TMDs) in nucleons are presented in this paper, based on the evaluation of nucleon matrix elements of quark bilocal operators with a staple-shaped gauge connection. Both time-reversal odd effects, namely, the generalized Sivers and Boer-Mulders transverse momentum shifts, as well as time-reversal even effects, namely, the generalized transversity and one of the generalized worm-gear shifts, are studied. Results are obtained on two different n_f = 2 + 1 flavor ensembles with approximately matching pion masses but very different discretization schemes: domain-wall fermions (DWF) with lattice spacing a = 0.084 fm and pion mass 297 MeV, and Wilson-clover fermions with a = 0.114 fm and pion mass 317 MeV. Comparison of the results on the two ensembles yields insight into the length scales at which lattice discretization errors are small, and into the extent to which the renormalization pattern obeyed by the continuum QCD TMD operator continues to apply in the lattice formulation. For the studied TMD observables, the results are found to be consistent between the two ensembles at sufficiently large separation of the quark fields within the operator, whereas deviations are observed in the local limit and in the casemore » of a straight link gauge connection, which is relevant to the studies of parton distribution functions. Finally and furthermore, the lattice estimates of the generalized Sivers shift obtained here are confronted with, and are seen to tend towards, a phenomenological estimate extracted from experimental data.« less

Authors:

Yoon, Boram ^[1]; Engelhardt, Michael ^[2]; Gupta, Rajan ^[1]; Bhattacharya, Tanmoy ^[1]; Green, Jeremy R. ^[3]; Musch, Bernhard U. ^[4]; Negele, John W. ^[5]; Pochinsky, Andrew V. ^[5]; Schäfer, Andreas ^[4]; Syritsyn, Sergey N. ^[6]

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+ Show Author Affiliations

1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2. New Mexico State Univ., Las Cruces, NM (United States). Dept. of Physics
3. Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)
4. Univ. of Regensburg (Germany). Inst. of Theoretical Physics
5. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Center for Theoretical Physics
6. Stony Brook Univ., NY (United States). Dept. of Physics and Astronomy; Brookhaven National Lab. (BNL), Upton, NY (United States). RIKEN/BNL Research Center

Publication Date:

Tue Nov 21 00:00:00 EST 2017

Research Org.:

Los Alamos National Lab. (LANL), Los Alamos, NM (United States); New Mexico State Univ., Las Cruces, NM (United States); Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Brookhaven National Lab. (BNL), Upton, NY (United States); Univ. of Regensburg (Germany)

Sponsoring Org.:

USDOE Office of Science (SC), High Energy Physics (HEP); USDOE Office of Science (SC), Nuclear Physics (NP); LANL Laboratory Directed Research and Development (LDRD) Program; National Science Foundation (NSF); German Research Foundation (DFG)

OSTI Identifier:

1415395

Alternate Identifier(s):

OSTI ID: 1409722

Report Number(s):

LA-UR-17-24472
Journal ID: ISSN 2470-0010; TRN: US1800795

Grant/Contract Number:  

AC52-06NA25396; AC02-05CH11231; AC05-06OR23177; FG02-96ER40965; SC0011090; FC02-06ER41444; ACI-1053575; SFB-TRR 55

Resource Type:

Accepted Manuscript

Journal Name:

Physical Review D

Additional Journal Information:

Journal Volume: 96; Journal Issue: 9; Journal ID: ISSN 2470-0010

Publisher:

American Physical Society (APS)

Country of Publication:

United States

Language:

English

Subject:

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; lattice QCD; particles & fields; nuclear physics