Twist-four effects in deep inelastic neutrino scattering and sin2theta/sub w/

In addition to the standard perturbative QCD corrections to deep inelastic scattering, there are nonperturbative twist-four corrections which behave like 1/Q2 relative to the lnQ2 leading log corrections. We have calculated the twist-four, spin-one and spin-two corrections to sigma/sub NC/, sigma/sub CC/, R/sub nu/ and R/sub anti nu/ using the following procedure: The bilocal product of the weak currents is expanded into local operators using the Wilson operator product expansion. The coefficient functions obey the renormalization group equations and, neglecting the anomalous dimensions of the operators, were calculated using perturbative techniques. The nucleon matrix elements of the local operators can then be evaluated assuming some quark confinement model. We found that twist-four, spin-two corrections to the neutral current neutrino scattering decreases sin2theta/sub w/ by about 1%. Taking into account the twist-four, spin-two corrections for the charged current cross section, we found that they give a dominant contribution to the ratio R/sub nu/ and increased sin2theta/sub w/ by about 0.5%. We also have studied the model dependence of our results, and we have found that the twist-four, spin-two corrections to sin2theta/sub w/ are quite model dependent. The twist-four, spin-one corrections to the neutrino scattering were also calculated. These corrections come from two-quark, one-gluon operators and even at low Q2 their contribution was found to be considerably smaller than the twist-four, spin-two corrections