Test for chirality of heavy-lepton current in inclusive pion production by electron-positron annihilation

Abstract

Parity mixing in the weak current of charged heavy leptons causes a conspicuous forward-backward asymmetry in the $cos\ensuremath{\theta}$ distribution of inclusive hadron spectra near the high-energy end, when one of the initial electron-positron beams is longitudinally polarized. The asymmetry is estimated for vector and axial-vector currents at PEP and PETRA energies. It is quite easy to distinguish experimentally between $V\ensuremath{-}A$ and $V+A$ provided that the decay branching ratio ${L}^{\ifmmode\pm\else\textpm\fi{}}$ into $L\ensuremath{\rightarrow}{\ensuremath{\nu}}_{L}+\ensuremath{\pi}$ is not too far from the value predicted by universality (\ensuremath{\sim} 10%).