Abstract
Using the ARGUS detector at the e+e- storage ring DORIS II, we have measured the Michel parameters ρ, ξ, and ξδ for τ± → l± νν̄ decays in τ-pair events produced at center of mass energies in the region of the γ resonances. Using τ± → ρ±ν as spin analyzing tags, we find ρe = 0.68 ± 0.04 ± 0.08, ξe = 1.12 ± 0.20 ± 0.09, ξδe = 0.57 ± 0.14 ± 0.07, ρμ = 0.69 ± 0.06 ± 0.08, ξμ = 1.25 ± 0.27 ± 0.14 and ξδμ = 0.72 ± 0.18 ± 0.10. In addition, we report the combined ARGUS results on ρ, ξ, and ξδ using this work und previous measurements.
Original language | English |
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Pages (from-to) | 179-187 |
Number of pages | 9 |
Journal | Physics Letters B |
Volume | 431 |
Issue number | 1-2 |
DOIs | |
State | Published - 9 Jul 1998 |
Externally published | Yes |