CONSTRAINTS ON NONSTANDARD CONTRIBUTIONS TO THE CHARGED-CURRENT INTERACTIONS

The success of the quantum level predictions of the Standard Model on the Z boson properties, on m(w) and on m(t), which makes use of the mu on life time as an input, implies a stringent constraint on new physic s contributions to the V-A charged-current interactions among leptons. Observed unitarity of the CKM matrix elements then implies constraint s on non-standard contributions to the lepton-quark charged-current in teractions. By using the recent electroweak; data as inputs, we find t hr 95% CL limits for the corresponding contact interactions: A(CC.+)(l l) purely leptonic terms, and A(CC.+)(ll) > 5.X TeV and A(CC.-)'(q) > 10.1 TeV for the Published by Elsevier Science B.V.