PRECISION LOW ENERGY WEAK NEUTRAL CURRENT EXPERIMENTS

Abstract

Precision measurements of weak neutral current amplitudes at [Formula: see text] are a sensitive probe of contact interactions arising from new high energy physics. Such measurements significantly enhance the analysis of precision data on the Z0 resonance, permitting tests of the running of the electroweak coupling constants. The behavior of the coupling constants as a function of Q2 can reveal the presence of many possible new physics scenarios, such as new gauge bosons, superparticles and substructure; some of these effects are difficult to observe on the Z0 pole. In order to probe energy scales up to 1 TeV, future low Q2 measurements must be precise enough to measure electroweak radiative corrections. Two experimental programs which aim to reach this sensitivity are deep inelastic neutrino nucleon scattering and atomic parity violation experiments. Another important technique is polarized electron scattering off unpolarized targets. We review the current status and future prospects of such measurements. We present an experimental design to measure the left-right parity violating asymmetry in polarized Møller scattering (e−e−→e−e−), which could constitute the most precise measurement of the weak mixing angle [Formula: see text] at [Formula: see text].