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Title: Strange-quark asymmetry in the proton in chiral effective theory

We perform a comprehensive analysis of the strange-antistrange parton distribution function (PDF) asymmetry in the proton in the framework of chiral effective theory, including the full set of lowest-order kaon loop diagrams with off-shell and contact interactions, in addition to the usual on-shell contributions previously discussed in the literature. We identify the presence of δ-function contributions to the s¯ PDF at x = 0, with a corresponding valencelike component of the s-quark PDF at larger x, which allows greater flexibility for the shape of s–s¯. Expanding the moments of the PDFs in terms of the pseudoscalar kaon mass, we compute the leading nonanalytic behavior of the number and momentum integrals of the s and s¯ distributions, consistent with the chiral symmetry of QCD. Lastly, we discuss the implications of our results for the understanding of the NuTeV anomaly and for the phenomenology of strange-quark PDFs in global QCD analysis.
 [1] ;  [2] ;  [3] ;  [4] ;  [5] ;  [6]
  1. Univ. of Adelaide, Adelaide (Australia). CoEPP and CSSM
  2. North Carolina State Univ., Raleigh, NC (United States)
  3. Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
  4. CAS, Beijing (China). Institute of High Energy Physics
  5. Univ. of Adelaide, Adelaide (Australia)
  6. CAS, Beijing (China). Institute of High Energy Physics; CAS, Beijing (China). Theoretical Physics Center for Science Facilities
Publication Date:
OSTI Identifier:
Report Number(s):
JLAB-THY-16-2357; DOE/OR/23177-3956; arXiv:1610.03333; ADP-16-35/T991
Journal ID: ISSN 2470-0010; PRVDAQ; TRN: US1701200
Grant/Contract Number:
AC05-06OR23177; FG02-03ER41260; CE110001104; FL0992247; DP151103101; 313800/2014-6; 400826/2014-3; 11475186; CRC 110
Accepted Manuscript
Journal Name:
Physical Review D
Additional Journal Information:
Journal Volume: 94; Journal Issue: 9; Journal ID: ISSN 2470-0010
American Physical Society (APS)
Research Org:
Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Nuclear Physics (NP) (SC-26)
Country of Publication:
United States