Contribution of Vector Mesons and Spin-1 Diquark to the Nucleon Structure Functions

Journal Article · Mon May 23 04:00:00 EDT 2011 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.3575025· OSTI ID:21513317

Zamani, F ^[1]

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1. Department of Physics, Villanova University. 800 East Lancaster Ave, Villanova, PA 19085 (United States)

In our previous works [1-7] we used both symmetrical (no diquark) core quark distribution and asymmetrical (diquark-quark) core quark distribution along with pseudoscalar mesons and vector mesons to calculate polarized [1,5,6] and unpolarized [2-4,7] nucleon structure functions. For the asymmetrical distribution we considered the superposition of spin-0, isospin-0 and spin-0, isospin-1 along with spin-0, isospin-0 and spin-1 isospin-1 states. It turned out that for unpolarized structure functions only the quark-diquark model was able to reproduce experimental results reasonably well [2-4,7]. Also, one needs the contribution of vector mesons to reproduce the observed Gottfried sum-rule violation [13]. However, for the polarized case the results were rather mixed. For some case the symmetrical model was more agreeable with observation [1,5,6]. Our objective here is to have a core quark distribution that can reproduce observation equally well, whether it is for the polarized structure function or the unpolarized structure function. To achieve this goal we have added the other two possible states to the diquark state. Namely, spin-1, isospin-0 and spin-1, isospin-1 and the contribution of both pseudoscalar mesons and vector mesons. The calculation is performed in the light-cone frame. The dressed nucleon is assumed to be a superposition of the bare nucleon plus virtual light-cone Fock states of baryon-meson pairs. For bare nucleon we consider both the case of diquark-quark model which is now the superposition of all four diquark states and the case which there is no quark clustering inside the nucleon. The initial distributions are evolved using DGLAP equations. The final results are compared with experimental results and other theoretical predictions.

• OSTI ID: 21513317
• Journal Information: AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 1343; ISSN APCPCS; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ANGULAR MOMENTUM
BARYONS
BOSONS
COMPOSITE MODELS
DISTRIBUTION
ELECTRICAL PROPERTIES
ELEMENTARY PARTICLES
EQUATIONS
FERMIONS
FORECASTING
FUNCTIONS
HADRONS
INTERACTIONS
ISOSPIN
LIGHT CONE
MATHEMATICAL MODELS
MESONS
NUCLEONS
PARTICLE MODELS
PARTICLE PROPERTIES
PHYSICAL PROPERTIES
POLARIZABILITY
POLARIZATION
PSEUDOSCALAR MESONS
QUARK MODEL
QUARKS
SPACE-TIME
SPIN
STRUCTURE FUNCTIONS
SUM RULES
VECTOR MESONS