Leading and higher twists in proton, neutron and deuteron unpolarized structure functions F2

Conference · Thu Mar 01 04:00:00 EST 2007 · Eur.Phys.J.A

DOI:https://doi.org/10.1140/epja/i2006-10246-x· OSTI ID:903059

Simula, S

We summarize the results of a recent global analysis of proton and deuteron F2 structure function world data performed over a large range of kinematics, including recent measurements done at JLab with the CLAS detector. From these data the lowest moments (n≤10) of the unpolarized structure functions are determined with good statistics and systematics. The Q2 evolution of the extracted moments is analyzed in terms of an OPE-based twist expansion, taking into account soft-gluon effects at large x. A clean separation among the leading- and higher-twist terms is achieved. By combining proton and deuteron measurements the lowest moments of the neutron F2 structure function are determined and its leading-twist term is extracted. Particular attention is paid to nuclear effects in the deuteron, which become increasingly important for the higher moments. Our results for the non-singlet, isovector (p-n) combination of the leading-twist moments are used to test recent lattice simulations. We also determine the lowest few moments of the higher-twist contributions, and find these to be approximately isospin independent, suggesting the possible dominance of ud correlations over uu and dd in the nucleon.

• Research Organization: Thomas Jefferson National Accelerator Facility, Newport News, VA
• Sponsoring Organization: USDOE - Office of Energy Research (ER)
• DOE Contract Number: AC05-84ER40150
• OSTI ID: 903059
• Report Number(s): JLAB-PHY-06-610; DOE/ER/40150-4266; hep-ph/0610153
• Conference Information: Journal Name: Eur.Phys.J.A Journal Volume: 31
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
DEUTERONS
ISOSPIN
ISOVECTORS
NEUTRONS
PARTICLE KINEMATICS
PROTONS
STRUCTURE FUNCTIONS