Excess of τ +τ - V events in Z decays A naive look

Abstract

The ALEPH Collaboration has analyzed the decays Z→ℓ +ℓ − V (V = e +e −, μ + μ −, π + π −), where ℓ is a lepton (ℓ=e, μ, τ). A possible excess of events is observed when ℓ is the τ lepton. We find that the observed kinematic distributions can be reproduced by assuming that (i) a new vector boson S couples vectorially to the τ, and (ii) the vector boson S decays into a V (through virtual Z exchange) and a pair of neutral scalar particles ζ.