Constraints on charm-anticharm asymmetry in the nucleon from lattice QCD
| Autor: | Hans Günter Dosch, Stanley J. Brodsky, Tiehui Liu, Andrei Alexandru, Yi-Bo Yang, Keh-Fei Liu, Guy F. de Teramond, Terrence Draper, Raza Sabbir Sufian |
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| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Quark
Nuclear and High Energy Physics Particle physics Nuclear Theory High Energy Physics::Lattice FOS: Physical sciences Nucleon spin structure Lattice QCD 01 natural sciences Charm quark High Energy Physics - Experiment Nuclear Theory (nucl-th) High Energy Physics - Experiment (hep-ex) High Energy Physics - Phenomenology (hep-ph) High Energy Physics - Lattice 0103 physical sciences Charm (quantum number) 010306 general physics Nuclear Experiment Light-front holographic QCD Quantum chromodynamics Physics 010308 nuclear & particles physics Parton distributions High Energy Physics - Lattice (hep-lat) High Energy Physics::Phenomenology Form factor (quantum field theory) Form factor lcsh:QC1-999 High Energy Physics - Phenomenology Intrinsic charm High Energy Physics::Experiment Nucleon lcsh:Physics |
| Zdroj: | Physics Letters B, Vol 808, Iss, Pp 135633-(2020) Physics Letters |
| Popis: | We present the first lattice QCD calculation of the charm quark contribution to the nucleon electromagnetic form factors $G^c_{E,M}(Q^2)$ in the momentum transfer range $0\leq Q^2 \leq 1.4$ $\rm GeV^2$. 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 $\mu^c_M=-0.00127(38)_{\rm stat}(5)_{\rm sys}$, as well as the Pauli form factor, reflects a nontrivial role of the charm sea in the nucleon spin structure. The nonzero $G^c_{E}(Q^2)$ 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 $[c(x)-\bar{c}(x)]$ 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. Comment: Published version, Physics Letters B |
| Databáze: | OpenAIRE |
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