The early observation at HERA of an excess of events compared to the
expectation from the Standard Model in very short distance e+p
deep-inelastic scattering processes has renewed the interest in the search for
new physics which could manifest in electroweak-like interactions. New
preliminary results from the H1 and ZEUS experiments making use of all
available e+p data are reviewed here, with an emphasis on the search for new
bosons possessing Yukawa couplings to lepton-quark pairs. The sensitivity of
HERA to leptoquarks, and to squarks of R-parity violating supersymmetry, is
confronted to existing indirect constraints from rare and forbidden
semi-leptonic decays, atomic parity violation and neutrinoless double-beta
decay, as well as to direct constraints from LEP and Tevatron colliders. The
HERA and Tevatron colliders are found to offer exciting prospects for new
physics, accessing yet unexplored domains of the mass-coupling plane. Possible
striking manifestation of explicit lepton flavour violation is also discussed.Comment: 27 pages, 16 figures. Proceedings of the WEIN'98 Symposium (June
1998
