The lepton flavor violating decay τS-S → μ-η was investigated using data sample of 84.3 fb-1 accumulated with the Belle detector at KEK. The detection of η meson was observed through the decay modes of η→γγ and π+π -π0. The minimum photon energy requirement was reduced from 0.1 to 0.005 GeV, as photons from this decay were found to have softer energy distribution compared to those in η→γγ. The results show that an upper limit for branching fraction B < 3.4×10-7 at about 90% confidence level.
Bibliographical noteFunding Information:
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 NII for valuable computing and Super-SINET network support. We are grateful to Y. Okada for fruitful discussions on theoretical aspects of spin correlations. We also thank A. Dedes and J. Hisano for important and useful comments about model dependence of limits on SUSY parameters. We acknowledge support from MEXT and JSPS (Japan); ARC and DEST (Australia); NSFC (Contract No. 10175071, China); DST (India); the BK21 program of MOEHRD and the CHEP SRC program of KOSEF (Korea); KBN (Contract No. 2P03B 01324, Poland); MIST (Russia); MESS (Slovenia); NSC and MOE (Taiwan); and DOE (USA).
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)