Lattice QCD Constraints on the Parton Distribution Functions of ^{3}He.

Autor: Detmold W; Center for Theoretical Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA., Illa M; Departament de Física Quàntica i Astrofísica and Institut de Ciències del Cosmos, Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona, Spain., Murphy DJ; Center for Theoretical Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA., Oare P; Center for Theoretical Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA., Orginos K; Department of Physics, College of William and Mary, Williamsburg, Virginia 23187-8795, USA.; Jefferson Laboratory, 12000 Jefferson Avenue, Newport News, Virginia 23606, USA., Shanahan PE; Center for Theoretical Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA., Wagman ML; Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA., Winter F; Jefferson Laboratory, 12000 Jefferson Avenue, Newport News, Virginia 23606, USA.
Jazyk: angličtina
Zdroj: Physical review letters [Phys Rev Lett] 2021 May 21; Vol. 126 (20), pp. 202001.
DOI: 10.1103/PhysRevLett.126.202001
Abstrakt: The fraction of the longitudinal momentum of ^{3}He that is carried by the isovector combination of u and d quarks is determined using lattice QCD for the first time. The ratio of this combination to that in the constituent nucleons is found to be consistent with unity at the few-percent level from calculations with quark masses corresponding to m_{π}∼800  MeV. With a naive extrapolation to the physical quark masses, this constraint is consistent with, and more precise than, determinations from global nuclear parton distribution function fits through the nnnpdf framework. It is thus concretely demonstrated that lattice QCD calculations of light nuclei have imminent potential to enable more precise determinations of the u and d parton distributions in light nuclei and to reveal the QCD origins of the EMC effect.
Databáze: MEDLINE