Introduction

1. Electromagnetic structure functions and neutrino nucleon scattering M.H. Reno Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52242 USA Introduction Capella et al (CKMT) parameterization The parameterization of the eP electromagnetic F2 is the following, where B and f are calculated according to valence quark counting: CKMT for neutrino scattering The parameterization of the charged current F2 requires a few modifications. For F2 [6], Fig. 2. Neutrino nucleon scattering cross section normalized to incident energy for W>1.4 GeV (dashed) and W>2 GEV (solid). The upper dashed (solid) line is for NLO+TMC, the lower dashed (solid) lines are using CKMT and BYP below Q0=2 GeV. These parameters are simple modifications of the CKMT fit to ep scattering data. Again, B and f are calculated, while A is fixed at large Q. They agree well with standard NLO+TMC structure functions at large Q. We use the CKMT parameterization, and for comparison, the BYP parameterizations for Q<Q0=2 GeV. Our results are shown in Figs. 2 and 3 for neutrinos and antineutrinos. • Conclusions • Similar results are obtained using the CKMT and BYP parameterizations. • The low Q corrections reduce the standard results by about 10% for neutrinos and 20% for antineutrinos. • Future work will include PCAC corrections for CC scattering. Fig. 1.Ratio of muon neutrino DIS charged current cross section as a function of minimum Q to the total DIS charged current cross section. The incident neutrino energy is 5 GeV, and NLO QCD and target mass corrections are included. Low Q extrapolations One approach to low Q extrapolations of structure functions has been pioneered by Bodek and Yang, joined by Park[4] (BYP). This is based on modifications of the Gluck, Reya and Vogt GRV98 parton distribution functions [5] to reflect low Q electromagnetic and weak structure functions. Instead, we consider the parameterization of Capella et al. [6], who made a fit to electron-proton scattering data. It is modified for neutrino isoscalar nucleon charged current scattering. • References • P. Lipari, M. Lusignoli and F. Sartogo, Phys. Rev. Lett. 74, 4384 (1995). • M. H. Reno, hep-ph/0605295. • S. Kretzer and M. H. Reno, Phys. Rev. D69, 034002 (2004), Phys. Rev. D66, 113007 (2002). • U.K. Yang and A. Bodek, Phys. Rev. Lett. 82, 2467 (1999); hep-ex/0308007; A. Bodek, I. Park and U.K. Yang, Nucl. Phys. Proc. Suppl. 139, 113 (2005). • M. Gluck, E. Reya and A. Vogt, Eur. Phys. J. C5, 461 (1998). • A. Capella, A. Kaidalov, C. Merino, and J. Tran Thanh Van, Phys. Lett. B 337, 358 (1994); Proceedings of 29th Rencontres de Moriond, 1994, pp. 271-282. Fig. 3.Antineutrino nucleon scattering cross section normalized to incident energy for W>1.4 GeV (dashed) and W>2 GEV (solid). The upper dashed (solid) line is for NLO+TMC, the lower dashed (solid) lines are using CKMT and BYP below Q0=2 GeV. AcknowledgmentsThis work is supported in part by D.O.E. contract DE-FG02-91ER40664. S. Kretzer is acknowledged for his contributions to the work on target mass corrections.