LEPTOQUARK PRODUCTION IN ULTRAHIGH-ENERGY NEUTRINO INTERACTIONS REEXAMINED

The prospects for producing leptoquarks (LQs) in ultrahigh-energy (UHE ) neutrino nucleon collisions are reexamined in the light of recent in terpretations of DESY HERA data in terms of leptoquark production. We update predictions for cross sections for the production of first- and second-generation leptoquarks in UHE nu-N and <(nu)over bar>-N collis ions including (i) recent experimental limits on masses and couplings from the CERN LEP and Fermilab Tevatron colliders as well as rare proc esses, (ii) modern parton distributions, and (iii) radiative correctio ns to single leptoquark production. If the HERA events are due to an S U(2) doubler leptoquark that couples mainly to e(+)q states, we argue that then are likely other LQ states that couple to neutrinos that are close in mass, due to constraints from precision electroweak measurem ents.