Determination of the Michel parameters 6 and 8 in leptonic T decays

Using the ARGUS detector at the e+e- storage ring DORIS II, we have determined the Michel parameters 6 and 6 of T? + lTfvV decays. With an integrated luminosity of 445 pb-’ around fi = 10 GeV, we have produced approximately 415000 r-pairs. From this data sample, 3262 events were selected with e’e- + T+T- --+ (l*tvT) (&~+.rr-y). The semihadronic decay was used as analyser of the r-spin and made possible - owing to the spin correlations - the determination of the parity-violating Michel parameters 5 and S in the decay rT -+ lTyi% Simultaneously to the determination of the