Nucleon Structure Functions from High-Energy Neutrino and Anti-Neutrino Interactions in Iron
- Columbia U.
Charged current nucleon structure functions obtained from high energy neutrino and antineutrino interactions in iron are presented. These were extracted from two separate exposures using the Fermilab narrow band beam. The structure functions were used to test the validity of two Quark Parton Model predictions: (1) $$F_2$$ measurements from this analysis were compared to those from charged lepton scattering experiments, indicating that both probes reveal the same nucleon structure. (2) The Gross-Llewellyn Smith sum rule, which measures the valance quark content of the nucleon, was evaluated at $Q^2$ = 3 (GeV/$c)^2$ , yielding the value 2.79±0.08±0.13 which lies below the Quark Parton Model prediction of three. When perturbative QCD corrections to this prediction are included, the measurement is consistent with a value of the QCD scale parameter $$\Lambda_{\overline{MS}}$$ < 435 MeV/c. Scaling violations were analysed in the context of perturbative QCD through the Altarelli-Parisi evolution equations. A nonsinglet fit to $$xF_3$$, which is independent of the unmeasured gluon density, yielded $$\Lambda_{\overline{MS}}= 251^{+134}_{-115}$$ ± 89 MeV/c. A singlet analysis of $$F_2$$, which does depend on the gluon density, yielded $$\Lambda_{\overline{MS}} = 255^{+73}_{-63}$$ ± 101 MeV/c. By simultaneously evolving $$F_2$$ and $$xF_3$$ , this error was reduced by about 303 and the shape of the gluon density was significantly constrained by the difference $$F_2 - xF_3$$ which measures the virtual $$q\overline{q}$$ content of the nucleon.
- Research Organization:
- Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), High Energy Physics (HEP)
- DOE Contract Number:
- AC02-07CH11359
- OSTI ID:
- 1427781
- Report Number(s):
- FERMILAB-THESIS-1989-23; NEVIS-270; CU-376; R-1460; 293064
- Country of Publication:
- United States
- Language:
- English
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