The decay τ-→ K*- η ν τ has been observed with the CLEO II detector. The K*- is reconstructed in two decay channels, K*-→ KSπ-→π+π- and K*-→ K-π0. The η is reconstructed from the decay η → γγ. The measured branching fraction isB(τ-→ K*-π η ντ)=(2.9 ± 0.8 ±0.4) × 10-44. We also measure the inclusive branching fractions without requiring the K* resonance, B(τ-→ KSπ- η ντ)=(1.10 ± 0.35 ±0.11) × 10-4 and B(τ-→ K-π0 η ντ)=(1.77 ± 0.56 ±0.71) × 10-4. The results indicate that the K*- resonance dominates the KSπ- mass spectrum.
Bibliographical noteFunding Information:
We gratefully acknowledge the essential contributions of Mari Kitayabu, which are described in her bachelor thesis at Nagoya University. We thank the KEKB group for the excellent operation of the accelerator, the KEK cryogenics group for the efficient operation of the solenoid, and the KEK computer group and the National Institute of Informatics for valuable computing and Super-SINET network support. We acknowledge support from the Ministry of Education, Culture, Sports, Science, and Technology of Japan and the Japan Society for the Promotion of Science; the Australian Research Council and the Australian Department of Education, Science and Training; the National Science Foundation of China and the Knowledge Innovation Program of the Chinese Academy of Sciences under contract No. 10575109 and IHEP-U-503; the Department of Science and Technology of India; the BK21 program of the Ministry of Education of Korea, the CHEP SRC program and Basic Research program (grant No. R01-2005-000-10089-0) of the Korea Science and Engineering Foundation, and the Pure Basic Research Group program of the Korea Research Foundation; the Polish State Committee for Scientific Research; the Ministry of Science and Technology of the Russian Federation; the Slovenian Research Agency; the Swiss National Science Foundation; the National Science Council and the Ministry of Education of Taiwan; and the US Department of Energy.