Constraints on charm-anticharm asymmetry in the nucleon from lattice QCD
We present the first lattice QCD calculation of the charm quark contribution to the nucleon electromagnetic form factors GE,Mc(Q2) in the momentum transfer range 0≤Q2≤1.4GeV2. The quark mass dependence, finite lattice spacing and volume corrections are taken into account simultaneously based on the...
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Published in | Physics letters. B Vol. 808; no. C; p. 135633 |
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Main Authors | , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
Netherlands
Elsevier B.V
10.09.2020
Elsevier |
Subjects | |
Online Access | Get full text |
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Summary: | We present the first lattice QCD calculation of the charm quark contribution to the nucleon electromagnetic form factors GE,Mc(Q2) in the momentum transfer range 0≤Q2≤1.4GeV2. The quark mass dependence, finite lattice spacing and volume corrections are taken into account simultaneously based on the calculation on three gauge ensembles including one at the physical pion mass. The nonzero value of the charm magnetic moment μMc=−0.00127(38)stat(5)sys, as well as the Pauli form factor, reflects a nontrivial role of the charm sea in the nucleon spin structure. The nonzero GEc(Q2) indicates the existence of a nonvanishing asymmetric charm-anticharm sea in the nucleon. Performing a nonperturbative analysis based on holographic QCD and the generalized Veneziano model, we study the constraints on the [c(x)−c¯(x)] distribution from the lattice QCD results presented here. Our results provide complementary information and motivation for more detailed studies of physical observables that are sensitive to intrinsic charm and for future global analyses of parton distributions including asymmetric charm-anticharm distribution. |
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Bibliography: | National Science Foundation (NSF) Chinese Academy of Sciences (CAS) USDOE Office of Science (SC), Nuclear Physics (NP) AC05-06OR23177; FG02-95ER40907; SC0013065; XDC01040100; AC05-00OR22725; ACI-1053575 JLAB-THY-20-3155; DOE/OR/23177-4935; arXiv:2003.01078; SLAC-PUB-17515; DOE-UKY-13065-2003.01078 |
ISSN: | 0370-2693 1873-2445 |
DOI: | 10.1016/j.physletb.2020.135633 |