Ameasurement of the Tau Mass and a First Test of CPT with Tau Leptons          
  
        We measure the mass of the tau lepton to be                            
              1775.1 +/- 1.6(stat.) +/- 1.0(sys.) MeV                          
        using tau pairs from Z^0 decays. To test CPT invariance we             
        compare the masses of the poisitively and negatively charged           
        tau leptons. The relative mass difference is found to be               
        smaller than 3.0 x 10^-3 at the 90% confidence level.                  
  
 Parallel session :7<br>11             
 Plenary  session :3<br>7a