Strategies to overcome the imprecision in Mw

While the precision in the measurement of Mz will improve greatly as LEP statistics increase, the best limit on 6Mw from hadron colliders is expected to approach 190 MeV, giving an uncertainty 6 Ar) = 0.018 compared with the present measured value Ar = 0.061 0.081. The precision in Mw will improve to 100 MeV when ultimately LEP 2 collects data on W W pair production. By then we expect the uncertainties on Ar to approach the value 6 Ar) 0.0056. Referring to Fig. 7.1 we see that such an evaluation of Ar would be quite useful in pinning down the unknown parameters of the theory. 

One can now repeat this exercise for other experimental quantities E, E2, . Each will yield a numerical function  

8GeV/c2 mn 6 TeV/c (68% CL) with the preferred value oimfj being less than Mz- 

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