Journal Article

FZJ-2017-04137

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Up, down, and strange nucleon axial form factors from lattice QCD

Green, J. (Corresponding author) ; Hasan, N.FZJ* ; Meinel, S. ; Engelhardt, M. ; Krieg, S.FZJ* ; Laeuchli, J. ; Negele, J. ; Orginos, K. ; Pochinsky, A. ; Syritsyn, S.

2017
Inst. Woodbury, NY

This record in other databases:    

Please use a persistent id in citations: http://hdl.handle.net/2128/14704  doi:10.1103/PhysRevD.95.114502

Abstract: We report a calculation of the nucleon axial form factors $G_A^q(Q^2)$ and $G_P^q(Q^2)$ for all three light quark flavors $q\in\{u,d,s\}$ in the range $0\leq Q^2\lesssim 1.2\text{ GeV}^2$ using lattice QCD. This work was done using a single ensemble with pion mass 317 MeV and made use of the hierarchical probing technique to efficiently evaluate the required disconnected loops. We perform nonperturbative renormalization of the axial current, including a nonperturbative treatment of the mixing between light and strange currents due to the singlet-nonsinglet difference caused by the axial anomaly. The form factor shapes are fit using the model-independent $z$ expansion. From $G_A^q(Q^2)$, we determine the quark contributions to the nucleon spin and axial radii. By extrapolating the isovector $G_P^{u-d}(Q^2)$, we obtain the induced pseudoscalar coupling relevant for ordinary muon capture and the pion-nucleon coupling constant. We find that the disconnected contributions to $G_P$ form factors are large, and give an interpretation based on the dominant influence of the pseudoscalar poles in these form factors.

---

Contributing Institute(s):

1. Jülich Supercomputing Center (JSC)

Research Program(s):

1. 511 - Computational Science and Mathematical Methods (POF3-511) (POF3-511)

Appears in the scientific report 2017

---

Database coverage:
; ; ; Current Contents - Physical, Chemical and Earth Sciences ; Ebsco Academic Search ; IF < 5 ; JCR ; SCOPUS ; Science Citation Index ; Science Citation Index Expanded ; Thomson Reuters Master Journal List ; Web of Science Core Collection

---