BOUNDS ON CONTACT INTERACTIONS FROM LEP1 DATA AND HIGH-Q(2) HERA EVENTS

A contact four-fermion interaction between light quarks and electrons has been evoked as a possible explanation for the excess of events obs erved by HERA at high-Q(2). We explore the 1-loop effects of such inte raction in Gamma(Z(0) --> e(+)e(-)) measured at LEP and impose strong bounds on the lower limit of the effective scale. Our results are able to discard some of the contact interactions as possible explanation f or the HERA events. (C) 1997 Elsevier Science B.V.