Quark and Gluon Momentum Fractions in the Pion and in the Kaon
We present the full decomposition of the momentum fraction carried by quarks and gluons in the pion and the kaon. We employ three gauge ensembles generated with N_{f}=2+1+1 Wilson twisted-mass clover-improved fermions at the physical quark masses. For both mesons we perform a continuum extrapolation directly at the physical pion mass, which allows us to determine for the first time the momentum decomposition at the physical point. We find that the total momentum fraction carried by quarks is 0.575(79) and 0.683(50) and by gluons 0.402(53) and 0.422(67) in the pion and in the kaon, respectively, in the MS[over ¯] scheme and at the renormalization scale of 2 GeV. Having computed both the quark and gluon contributions in the continuum limit, we find that the momentum sum is 0.984(89) for the pion and 1.13(11) for the kaon, verifying the momentum sum rule.
Authors
- Urs Wenger (ORCID: https://orcid.org/0000-0002-7754-9590)
- Fernanda Steffens (ORCID: https://orcid.org/0000-0003-1875-9288)
- Carsten Urbach (ORCID: https://orcid.org/0000-0003-1412-7582)
- Joseph Delmar
- Bartosz Kostrzewa (ORCID: https://orcid.org/0000-0003-4434-6022)
- Jacob Finkenrath (ORCID: https://orcid.org/0000-0002-2122-2249)
- Gregoris Spanoudes (ORCID: https://orcid.org/0000-0001-7020-2570)
- Marcus Petschlies
- Simone Bacchio (ORCID: https://orcid.org/0000-0002-5532-450X)
- Martha Constantinou (ORCID: https://orcid.org/0000-0002-6988-1745)
- Luis Chacòn (ORCID: https://orcid.org/0000-0002-4566-8763)
- Constantia Alexandrou (ORCID: https://orcid.org/0000-0001-9136-3621)
Institutions
- University of Bern (CH)
- University of Bonn (DE)
- Cyprus Institute (CY)
- University of Wuppertal (DE)
- University of Ferrara (IT)
- Temple College (US)
- University of Cyprus (CY)
- Istituto Nazionale di Fisica Nucleare, Sezione di Ferrara (IT)
- Temple University (US)
Publication Details
- Journal
- Physical Review Letters
- Published
- 2025-03-31
- DOI
- https://doi.org/10.1103/physrevlett.134.131902
- Citations
- 7
- Primary Topic
- Particle physics theoretical and experimental studies
- Type
- article
- Field-Weighted Citation Impact
- 13.09
Funders
- U.S. Department of Energy
- University of Texas at Austin
- Deutsche Forschungsgemeinschaft
- Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung
- Research and Innovation Foundation
- CSC – IT Center for Science
- Centro Svizzero di Calcolo Scientifico
- European Regional Development Fund
- Nuclear Physics
- Northwest Fisheries Science Center
- HORIZON EUROPE Marie Sklodowska-Curie Actions