Comparison of the structure function $F_2$ as measured by charged lepton and neutrino scattering from iron targets

A comparison study of world data for the structure function $F_2$ for iron, as measured by both charged lepton and neutrino scattering experiments, is presented. Consistency of results for both charged lepton and neutrino scattering is observed for the full global data set in the valence regime. Consistency is also observed at low $x$ for the various neutrino data sets, as well as for the charged lepton data sets, independently. However, data from the two probes exhibit differences on the order of 15% in the shadowing-antishadowing transition region where the Bjorken scaling variable $x$ is $<0.15$. This observation is indicative that neutrino probes of nucleon structure might be sensitive to different nuclear effects than charged lepton probes. Details and results of the data comparison are presented here.

Figure 1

Scatter plot of available $F_2^{\mathrm{Fe}}$ data in $x,Q^2$ kinematics with the conventional deep inelastic scattering cuts applied. Charged lepton data are denoted by solid symbols, while neutrino data are denoted with open symbols.

Figure 2

$F_2^{\mathrm{Fe}}$ data vs $x$. Data were obtained over $Q^2$ ranges of $2–20{\mathrm{GeV}}^2$ (top) and $4–8{\mathrm{GeV}}^2$ (bottom). The data have been centered to a common $Q^2$ of $8{\mathrm{GeV}}^2$ (top) and $6{\mathrm{GeV}}^2$ (bottom) as described in the text. The curves also are as described in the text.

Figure 3

(top) A low $x$ magnification of Fig. 2 for a $Q^2$ range of $2–20{\mathrm{GeV}}^2$, with (bottom) ratio data/fit, of $F_2^{\mathrm{Fe}}$ to the CJ12 fit for charged current neutrino vs the Bjorken scaling variable $x$. In both cases, the data and fits are centered to a common $Q^2$ of $8{\mathrm{GeV}}^2$. Note that zero is suppressed in both plots.