Measurement of the branching fraction for tau --->5 pi +/-( pi 0) nu tau and an upper limit on the nu tau mass.

Author(s): Burchat, PR; Schmidke, WB; Yelton, JM; Abrams, G; Amidei, D; Baden, AR; Barklow, T; Boyarski, AM; Boyer, J; Breidenbach, M; Burke, DL; Butler, F; Dorfan, JM; Feldman, GJ; Gidal, G; Gladney, L; Gold, MS; Goldhaber, G; Golding, L; Haggerty, J; Hanson, G; Hayes, K; Herrup, D; Hollebeek, RJ; Innes, WR; Jaros, JA; Juricic, I; Kadyk, JA; Karlen, D; Lankford, AJ; Larsen, RR; LeClaire, BW; Levi, M; Lockyer, NS; Luth, V; Matteuzzi, C; Nelson, ME; Ong, RA; Perl, ML; Richter, B; Riles, K; Ross, MC; Rowson, PC; Schaad, T; Schellman, H; Sheldon, PD; Trilling, GH; de la Vaissiere C; Wood, DR; Zaiser, AC | Abstract: The branching fraction for -5(0) is measured from data accumulated with the Mark II detector at PEP. Four events are observed with an estimated hadronic background of (0.03-0.02+0.04) events and a background from -30 of (0.05-0.04+0.07) events. This results in a measured branching fraction of (0.160.080.04)%. The candidate events are used to establish an upper limit of 125 MeV/c2 on the mass at the 95% confidence level. © 1985 The American Physical Society.