Abstract
Using the ARGUS detector at the e+e- storage ring DORIS II, we have searched for the real and imaginary part of the electric dipole formfactor d(τ) of the τ lepton in the production of τ pairs at q2= 100GeV2. This is the first direct measurement of this CP violating formfactor. We applied the method of optimised observables which takes into account all available information on the observed τ decay products. No evidence for CP violation was found, and we derive the following results: Re(d(τ)) = (1.6 ± 1.9) · 10-16 e cm and Im(d(τ)) = (-0.2 ± 0.8) · 10-16 e cm, where statistical and systematic errors have been combined. (C) 2000 Elsevier Science B.V.
Original language | English |
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Pages (from-to) | 37-44 |
Number of pages | 8 |
Journal | Physics Letters B |
Volume | 485 |
Issue number | 1-3 |
DOIs | |
State | Published - 13 Jul 2000 |
Externally published | Yes |