2017/06/30 by Constantia Alexandrou, C. Alexandrou, Martha Constantinou +11 · 141 citations
Physics and Astronomy · #Condensed matter physics #High-Energy Particle Collisions Research #Lattice (music) #Lattice QCD #Momentum (technical analysis) #Nuclear physics #Nucleon #Particle physics #Particle physics theoretical and experimental studies #Physics #Quantum Chromodynamics and Particle Interactions #Quantum chromodynamics #Quantum electrodynamics #Statistical physics #hep-ex #hep-lat #hep-ph #nucl-ex #nucl-th
paper · pdf · doi:10.1103/physrevlett.119.142002
published in Physical Review Letters 119(14), 142002 (American Physical Society) · Version published in PRL
openalex publication_date 2017/10/06 · openalex created_date 2017/10/20 · arxiv created 2017/11/18 · arxiv updated 2017/11/21 · openalex updated_date 2026/08/06
We determine within lattice QCD the nucleon spin carried by valence and sea quarks and gluons. The calculation is performed using an ensemble of gauge configurations with two degenerate light quarks with mass fixed to approximately reproduce the physical pion mass. We find that the total angular momentum carried by the quarks in the nucleon is Ju+d+s=0.408(61)stat(48)syst and the gluon contribution is Jg=0.133(11)stat(14)syst, giving a total of JN=0.54(6)stat(5)syst that is consistent with the spin sum. For the quark intrinsic spin contribution, we obtain (1)/(2)\mathrm\ensuremathΔ\mathrm\ensuremathΣu+d+s=0.201(17)stat(5)syst. All quantities are given in the modified minimal subtraction scheme at 2 GeV. The quark and gluon momentum fractions are also computed and add up to ⟨x⟩u+d+s+⟨x⟩g=0.804(121)stat(95)syst+0.267(12)stat(10)syst=1.07(12)stat(10)syst, thus satisfying the momentum sum.