e+e− annihilation into hadrons at LEP2 in the presence of the anomalous DESY positron-jet event phenomenon

We discuss the allowed parameter regime in the coupling-mass plane implied by the existing LEP2 data on e+e− → hadrons at 172.3 GeV for the leptoquark interpretation of the anomalous DESY positron-jet events for four different models of the leptoquark charges and chiral couplings to quarks, for both a loose cut on s′s and a tight cut on s′s. We find that this interpretation of the DESY phenomenon is still consisten with the LEP2 data although, for vector leptoquarks, a significant regime of the relevant parameter space is already excluded.