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Title: Isovector charges of the nucleon from 2 + 1 -flavor QCD with clover fermions

We present high-statistics estimates of the isovector charges of the nucleon from four 2+1-flavor ensembles generated using Wilson-clover fermions with stout smearing and tree-level tadpole improved Symanzik gauge action at lattice spacings $a=0.114$ and $0.080$ fm and with $$M_\pi \approx 315$$ and 200 MeV. The truncated solver method with bias correction and the coherent source sequential propagator construction are used to cost-effectively achieve $O(10^5)$ measurements on each ensemble. Using these data, the analysis of two-point correlation functions is extended to include four states in the fits and of three-point functions to three states. Control over excited-state contamination in the calculation of the nucleon mass, the mass gaps between excited states, and in the matrix elements is demonstrated by the consistency of estimates using this multistate analysis of the spectral decomposition of the correlation functions and from simulations of the three-point functions at multiple values of the source-sink separation. Lastly, the results for all three charges, $$g_A$$, $$g_S$$ and $$g_T$$, are in good agreement with calculations done using the clover-on-HISQ lattice formulation with similar values of the lattice parameters.
Authors:
 [1] ;  [1] ;  [1] ;  [1] ;  [2] ;  [3] ;  [4] ;  [5] ;  [3] ;  [3] ;  [3]
  1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
  2. Johannes Gutenberg-Univ. Mainz, Mainz (Germany); Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)
  3. Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
  4. Univ. of California, Berkeley, CA (United States)
  5. College of William and Mary, Williamsburg, VA (United States)
Publication Date:
Report Number(s):
LA-UR-16-20523; JLAB-THY-16-2417; arXiv:1611.07452
Journal ID: ISSN 2470-0010; PRVDAQ; TRN: US1700538
Grant/Contract Number:
AC05-00OR22725; KA-1401020; AC05-06OR23177; AC52-06NA25396
Type:
Accepted Manuscript
Journal Name:
Physical Review D
Additional Journal Information:
Journal Volume: 95; Journal Issue: 7; Journal ID: ISSN 2470-0010
Publisher:
American Physical Society (APS)
Research Org:
Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org:
USDOE Office of Science (SC), Nuclear Physics (NP) (SC-26)
Contributing Orgs:
Nucleon Matrix Elements (NME) Collaboration
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
OSTI Identifier:
1351543
Alternate Identifier(s):
OSTI ID: 1351685; OSTI ID: 1409753