Constraints on electron-quark contact interactions and implications to models of leptoquarks and extra Z bosons

We update the global constraint on four-fermion eeqq contact interactions. In this update, we included the published data of H1 and ZEUS for the 1994-1996 run in the e(+) p mode and the newly published data of H1 for the 1999 run in the e(-) p mode. Other major changes are the new LEPII data on hadronic cross sections above 189 GeV, and the atomic parity violation measurement on cesium because of a new and improved atomic calculation, which drives the data within 1 sigma of the standard model value. The global data do not show any evidence for contact interactions, and we obtain 95% C.L. limits on the compositeness scale. A limit of Lambda (eu)(LL+(-)) > 23 (12.5) TeV is obtained. Implications to models of leptoquarks and extra Z bosons are examined. (C) 2001 Elsevier Science B.V. All rights reserved.