Antineutrino anomalies and right-handed currents

Abstract

We analyze the predictions of several gauge-theory models for inclusive charged-current antineutrino reactions on isoscalar, proton, and neutron targets. In particular, we calculate $y$ and $W$ distributions, average $y$, $B$ parameters, and cross-section ratios. Gauge models incorporating right-handed quark transitions of the type $u\to b$ and $d\to x$ are considered, where the heavy quarks $b$ and $x$ have charges -1/3 and -4/3, respectively. The effects of varying both the quark masses and the physical thresholds are examined. Experimental cuts and flux-averaging, where appropriate, are applied to the model predictions for the Fermilab counter and bubble-chamber experiments. We find that with reasonable choices of parameters, five- or six-quark models with valence-strength right-handed currents can fit most of the present experimental data to within one-standard-deviation accuracy.