Possible tests of anomalously large leptonic weak interactions in high-energy e⁺e⁻ collisions

Abstract

Some consequences of two possible mechanisms of a breakdown in V-A theory leading to anomalously large weak vertices in hitherto untested leptonic reactions are discussed. We consider the processes e⁺e⁻→ μ⁺μ⁻ and e⁺e⁻→ν_eν^~_eγ with total c.m. energies around 10 GeV. A purely leptonic neutral current can cause a measurable forward-backward muon asymmetry and a muon polarization in the first reaction. Expressions are computed for these effects in terms of the most general nonderivative coupling. On the other hand, some intrinsic anomaly in diagonal weak vertices can make the cross section for the second process large and measurable; in that case, study of the γ spectrum can reveal information about the structure of such an anomalous vertex. The angular distribution and the energy spectrum of the photon are computed for the V-A and S-P theories up to terms that are first order in (total c .m. energy)²/2 (intermediate-boson mass)².