Parity violation in atoms in SO(3) gauge models

Abstract

We have evaluated the parity-violation contribution in atoms in the framework of SO(3) gauge theory. Various hadronic models have been used: first, for simplicity, the unrealistic five-quark one, next, others involving three ordinary SU(3) triplets for which all unwanted strangeness-changing processes are suppressed, up to order Gα or GαΔM 2 M W 2 . In the free quark approximation, we obtain quite similar parity-violation effects which are proportional to GαΔM 2 M W 2 ( ΔM 2 is the difference of squared masses of leptons ( M X 0 2 − M ν 2 = M X 0 2), or of quarks ( ΔM q 2)). Namely, in large atoms ( Z ⪢ 1) the electronic contribution which is proportional to Gα M X 0 2 M W 2 Z σ ℓ· p ℓ m ℓ gives the largest effect ( σ ℓ, p ℓ and m ℓ are the spin, momentum operators and mass of the lepton). Parity-violating effects in SO(3) gauge models are ≅10 −4 smaller than those evaluated in the Weinberg theory with a neutral parity-violating current and will remain undetectable in the near future.