A low – energy compatible SU ( 4 ) – type Model for Vector Leptoquarks of Mass ≤ 1 TeV

The Standard Model is extended by a SU(2) L singlet of vector leptoquarks. An additional SU(4) gauge symmetry between right–handed up quarks and right– handed leptons is introduced to render the model renormalizable. The arrangement is made in such a way that no conflict with low energy restrictions is encountered. The SU(2) L singlet mediates interactions between the right–handed leptons and up type quarks for which only moderate low energy restrictions M LQ /g LQ > few hundred GeV exist. However, it is not a candidate to explain the anomalous HERA data at large Q 2 because theoretical reasons imply that g LQ ≥ g s which would give a much stronger anomalous HERA effect. We furthermore argue that the inequality g LQ ≥ g s is a general feature of consistent vector leptoquark models. Although our model is not relevant for HERA, it is interesting per se as a description of leptoquarks of mass ≤ 1 TeV consistent with all low–energy requirements.