/tau//r arrow/(3. pi. ). nu. /sub /tau// and light-meson spectroscopy

The 3/pi/ spectrum in /tau/ decay is studied by considering the contribution from the radially excited state (/ital a//sub 1//sup /prime//) of the /ital a//sub 1/ meson. It is shown that the spectrum is reasonably reproduced by the following values of the /ital a//sub 1/ and /ital a//sub 1//sup /prime// parameters. /ital m//sub /ital a//sub 1//=1.08--1.14 GeV, /Gamma//sub /ital a//sub 1//=0.36--0.40 GeV, /ital m//sub /ital a//sub 1//sup /prime/// =1.51--1.59 GeV, and /Gamma//sub /ital a//sub 1//sup /prime///=0.50--0.55 GeV or 0.75--0.90 GeV depending on the models for multiparticle decay modes. The implications of these results are discussed in connection with the classification of light mesons with masses below 2 GeV.