$\tau$ electric dipole moment with polarized beams

TL;DR

This paper explores how polarized beams at high-luminosity Super B/Flavor factories can be used to set new bounds on the tau lepton's electric dipole moment through CP-odd asymmetries, providing an independent analysis from existing data.

Contribution

It introduces a novel method using polarized electron beams and CP-odd asymmetries to improve bounds on the tau electric dipole moment, independent of previous analyses.

Findings

Polarized beams enable sensitive CP-odd asymmetry measurements.

The method can set more stringent bounds on the tau electric dipole moment.

Analysis is independent from other low and high energy data.

Abstract

High luminosity Super B/Flavor factories, near and on top of the $\Upsilon$ resonances, allow for a detailed investigation of CP-violation in $\tau$ physics. In particular, bounds on the $\tau$ electric dipole moment can be obtained from CP-odd observables. We perform an independent analysis from other low and high energy data. For polarized electron beam a CP-odd asymmetry, associated to the normal polarization term, can be used to set stringent bounds on the $\tau$ electric dipole moment.