Abstract
We report a measurement of the electric dipole moment of the τ lepton (dτ) using an 833 fb−1 data sample collected near the Υ(4S) resonance, with the Belle detector at the KEKB asymmetric-energy e+e− collider. Using an optimal observable method, we obtain the real and imaginary parts of dτ as Re(dτ) = (−0.62 ± 0.63) × 10−17 ecm and Im(dτ) = (−0.40 ± 0.32) × 10−17 ecm, respectively. These results are consistent with null electric dipole moment at the present level of experimental sensitivity and improve the sensitivity by about a factor of three.
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The BELLE collaboration., Inami, K., Hayasaka, K. et al. An improved search for the electric dipole moment of the τ lepton. J. High Energ. Phys. 2022, 110 (2022). https://doi.org/10.1007/JHEP04(2022)110
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DOI: https://doi.org/10.1007/JHEP04(2022)110