Prediction for CP Violation via Electric Dipole Moment of $\tau$ Lepton in ${\gamma\gamma \to \tau^{+}\tau^{-}}$ Process at CLIC

TL;DR

This paper investigates CP violation in tau lepton pair production at CLIC via gamma-gamma collisions, focusing on electric dipole moments and using tau decay correlations to set bounds on CP-violating couplings.

Contribution

It introduces a novel method to probe CP violation in tau leptons through spin correlations in gamma-gamma collisions at CLIC.

Findings

Established competitive bounds on tau electric dipole moments.

Demonstrated the sensitivity of tau decay correlations to CP-violating effects.

Provided constraints comparable to previous experimental limits.

Abstract

Pair production of tau leptons in two photon collision ${\gamma\gamma \to \tau^{+}\tau}^{-}$ is studied at CLIC to test CP violating QED couplings of tau leptons. CP violating effects are investigated using tau pair spin correlations which are observed through the hadronic decay of each $\tau$ into $\pi\nu$. Competitive bounds with previous works on the electric dipole moment from CP odd terms have been obtained.