Strange and charm quark spins from the anomalous Ward identity

doi:10.1103/PhysRevD.95.114509

Strange and charm quark spins from the anomalous Ward identity

Research output: Contribution to journal › Article › peer-review

14 Scopus citations

Abstract

We present a calculation of the strange and charm quark contributions to the nucleon spin from the anomalous Ward identity (AWI). This is performed with overlap valence quarks on 2+1-flavor domain-wall fermion gauge configurations on a 243×64 lattice with lattice spacing a-1=1.73 GeV and the light sea mass at mπ=330 MeV. To satisfy the AWI, the overlap fermion for the pseudoscalar density and the overlap Dirac operator for the topological density, which do not have multiplicative renormalization, are used to normalize the form factor of the local axial-vector current at finite q2. For the charm quark, we find that the negative pseudoscalar term almost cancels the positive topological term. For the strange quark, the pseudoscalar term is less negative than that of the charm. By imposing the AWI, the strange gA(q2) at q2=0 is obtained by a global fit of the pseudoscalar and the topological form factors, together with gA(q2) and the induced pseudoscalar form factor hA(q2) at finite q2. The chiral extrapolation to the physical pION mass gives Δs+Δs=-0.0403(44)(78).

Original language	English
Article number	114509
Journal	Physical Review D
Volume	95
Issue number	11
DOIs	https://doi.org/10.1103/PhysRevD.95.114509
State	Published - Jun 1 2017

Bibliographical note

Funding Information:
This work is supported in part by the National Science Foundation of China (NSFC) under Project No. 11405178, the Youth Innovation Promotion Association of CAS (2015013), and the U.S. DOE Grant No. DE-SC0013065. A.A. is supported in part by the National Science Foundation CAREER Grant No. PHY-1151648 and by U.S. DOE Grant No. DE-FG02-95ER40907. This research used resources of the Oak Ridge Leadership Computing Facility at the Oak Ridge National Laboratory, which is supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC05-00OR22725. This work also used the Extreme Science and Engineering Discovery Environment (XSEDE), which is supported by National Science Foundation Grant No. ACI-1053575.

Publisher Copyright:
© 2017 American Physical Society.

ASJC Scopus subject areas

Nuclear and High Energy Physics

Access to Document

10.1103/PhysRevD.95.114509

Cite this

@article{54fddb2f87ea4144a89902f6b0c9775c,

title = "Strange and charm quark spins from the anomalous Ward identity",

abstract = "We present a calculation of the strange and charm quark contributions to the nucleon spin from the anomalous Ward identity (AWI). This is performed with overlap valence quarks on 2+1-flavor domain-wall fermion gauge configurations on a 243×64 lattice with lattice spacing a-1=1.73 GeV and the light sea mass at mπ=330 MeV. To satisfy the AWI, the overlap fermion for the pseudoscalar density and the overlap Dirac operator for the topological density, which do not have multiplicative renormalization, are used to normalize the form factor of the local axial-vector current at finite q2. For the charm quark, we find that the negative pseudoscalar term almost cancels the positive topological term. For the strange quark, the pseudoscalar term is less negative than that of the charm. By imposing the AWI, the strange gA(q2) at q2=0 is obtained by a global fit of the pseudoscalar and the topological form factors, together with gA(q2) and the induced pseudoscalar form factor hA(q2) at finite q2. The chiral extrapolation to the physical pION mass gives Δs+Δs=-0.0403(44)(78).",

author = "Ming Gong and Yang, {Yi Bo} and Jian Liang and Andrei Alexandru and Terrence Draper and Liu, {Keh Fei}",

note = "Funding Information: This work is supported in part by the National Science Foundation of China (NSFC) under Project No. 11405178, the Youth Innovation Promotion Association of CAS (2015013), and the U.S. DOE Grant No. DE-SC0013065. A.A. is supported in part by the National Science Foundation CAREER Grant No. PHY-1151648 and by U.S. DOE Grant No. DE-FG02-95ER40907. This research used resources of the Oak Ridge Leadership Computing Facility at the Oak Ridge National Laboratory, which is supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC05-00OR22725. This work also used the Extreme Science and Engineering Discovery Environment (XSEDE), which is supported by National Science Foundation Grant No. ACI-1053575. Publisher Copyright: {\textcopyright} 2017 American Physical Society.",

year = "2017",

month = jun,

day = "1",

doi = "10.1103/PhysRevD.95.114509",

language = "English",

volume = "95",

number = "11",

}

TY - JOUR

T1 - Strange and charm quark spins from the anomalous Ward identity

AU - Gong, Ming

AU - Yang, Yi Bo

AU - Liang, Jian

AU - Alexandru, Andrei

AU - Draper, Terrence

AU - Liu, Keh Fei

N1 - Funding Information: This work is supported in part by the National Science Foundation of China (NSFC) under Project No. 11405178, the Youth Innovation Promotion Association of CAS (2015013), and the U.S. DOE Grant No. DE-SC0013065. A.A. is supported in part by the National Science Foundation CAREER Grant No. PHY-1151648 and by U.S. DOE Grant No. DE-FG02-95ER40907. This research used resources of the Oak Ridge Leadership Computing Facility at the Oak Ridge National Laboratory, which is supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC05-00OR22725. This work also used the Extreme Science and Engineering Discovery Environment (XSEDE), which is supported by National Science Foundation Grant No. ACI-1053575. Publisher Copyright: © 2017 American Physical Society.

PY - 2017/6/1

Y1 - 2017/6/1

N2 - We present a calculation of the strange and charm quark contributions to the nucleon spin from the anomalous Ward identity (AWI). This is performed with overlap valence quarks on 2+1-flavor domain-wall fermion gauge configurations on a 243×64 lattice with lattice spacing a-1=1.73 GeV and the light sea mass at mπ=330 MeV. To satisfy the AWI, the overlap fermion for the pseudoscalar density and the overlap Dirac operator for the topological density, which do not have multiplicative renormalization, are used to normalize the form factor of the local axial-vector current at finite q2. For the charm quark, we find that the negative pseudoscalar term almost cancels the positive topological term. For the strange quark, the pseudoscalar term is less negative than that of the charm. By imposing the AWI, the strange gA(q2) at q2=0 is obtained by a global fit of the pseudoscalar and the topological form factors, together with gA(q2) and the induced pseudoscalar form factor hA(q2) at finite q2. The chiral extrapolation to the physical pION mass gives Δs+Δs=-0.0403(44)(78).

AB - We present a calculation of the strange and charm quark contributions to the nucleon spin from the anomalous Ward identity (AWI). This is performed with overlap valence quarks on 2+1-flavor domain-wall fermion gauge configurations on a 243×64 lattice with lattice spacing a-1=1.73 GeV and the light sea mass at mπ=330 MeV. To satisfy the AWI, the overlap fermion for the pseudoscalar density and the overlap Dirac operator for the topological density, which do not have multiplicative renormalization, are used to normalize the form factor of the local axial-vector current at finite q2. For the charm quark, we find that the negative pseudoscalar term almost cancels the positive topological term. For the strange quark, the pseudoscalar term is less negative than that of the charm. By imposing the AWI, the strange gA(q2) at q2=0 is obtained by a global fit of the pseudoscalar and the topological form factors, together with gA(q2) and the induced pseudoscalar form factor hA(q2) at finite q2. The chiral extrapolation to the physical pION mass gives Δs+Δs=-0.0403(44)(78).

UR - http://www.scopus.com/inward/record.url?scp=85022340611&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85022340611&partnerID=8YFLogxK

U2 - 10.1103/PhysRevD.95.114509

DO - 10.1103/PhysRevD.95.114509

M3 - Article

AN - SCOPUS:85022340611

VL - 95

IS - 11

M1 - 114509

ER -

Strange and charm quark spins from the anomalous Ward identity

Abstract

Bibliographical note

ASJC Scopus subject areas

Access to Document

Other files and links

Fingerprint

Cite this