TY - JOUR
T1 - Sea quarks contribution to the nucleon magnetic moment and charge radius at the physical point
AU - Sufian, Raza Sabbir
AU - Yang, Yi Bo
AU - Liang, Jian
AU - Draper, Terrence
AU - Liu, Keh Fei
N1 - Publisher Copyright:
© 2017 American Physical Society.
PY - 2017/12/1
Y1 - 2017/12/1
N2 - We report a comprehensive analysis of the light and strange disconnected-sea quarks contribution to the nucleon magnetic moment, charge radius, and the electric and magnetic form factors. The lattice QCD calculation includes ensembles across several lattice volumes and lattice spacings with one of the ensembles at the physical pion mass. We adopt a model-independent extrapolation of the nucleon magnetic moment and the charge radius. We have performed a simultaneous chiral, infinite volume, and continuum extrapolation in a global fit to calculate results in the continuum limit. We find that the combined light and strange disconnected-sea quarks contribution to the nucleon magnetic moment is μM(DI)=-0.022(11)(09) μN and to the nucleon mean square charge radius is r2E(DI)=-0.019(05)(05) fm2 which is about 1/3 of the difference between the rp2E of electron-proton scattering and that of a muonic atom and so cannot be ignored in obtaining the proton charge radius in the lattice QCD calculation. The most important outcome of this lattice QCD calculation is that while the combined light-sea and strange quarks contribution to the nucleon magnetic moment is small at about 1%, a negative 2.5(9)% contribution to the proton mean square charge radius and a relatively larger positive 16.3(6.1)% contribution to the neutron mean square charge radius come from the sea quarks in the nucleon. For the first time, by performing global fits, we also give predictions of the light and strange disconnected-sea quarks contributions to the nucleon electric and magnetic form factors at the physical point and in the continuum and infinite volume limits in the momentum transfer range of 0≤Q2≤0.5 GeV2.
AB - We report a comprehensive analysis of the light and strange disconnected-sea quarks contribution to the nucleon magnetic moment, charge radius, and the electric and magnetic form factors. The lattice QCD calculation includes ensembles across several lattice volumes and lattice spacings with one of the ensembles at the physical pion mass. We adopt a model-independent extrapolation of the nucleon magnetic moment and the charge radius. We have performed a simultaneous chiral, infinite volume, and continuum extrapolation in a global fit to calculate results in the continuum limit. We find that the combined light and strange disconnected-sea quarks contribution to the nucleon magnetic moment is μM(DI)=-0.022(11)(09) μN and to the nucleon mean square charge radius is r2E(DI)=-0.019(05)(05) fm2 which is about 1/3 of the difference between the rp2E of electron-proton scattering and that of a muonic atom and so cannot be ignored in obtaining the proton charge radius in the lattice QCD calculation. The most important outcome of this lattice QCD calculation is that while the combined light-sea and strange quarks contribution to the nucleon magnetic moment is small at about 1%, a negative 2.5(9)% contribution to the proton mean square charge radius and a relatively larger positive 16.3(6.1)% contribution to the neutron mean square charge radius come from the sea quarks in the nucleon. For the first time, by performing global fits, we also give predictions of the light and strange disconnected-sea quarks contributions to the nucleon electric and magnetic form factors at the physical point and in the continuum and infinite volume limits in the momentum transfer range of 0≤Q2≤0.5 GeV2.
UR - http://www.scopus.com/inward/record.url?scp=85040357221&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85040357221&partnerID=8YFLogxK
U2 - 10.1103/PhysRevD.96.114504
DO - 10.1103/PhysRevD.96.114504
M3 - Article
AN - SCOPUS:85040357221
SN - 2470-0010
VL - 96
JO - Physical Review D
JF - Physical Review D
IS - 11
M1 - 114504
ER -