Study $\gamma\gamma \to \tau^+\tau^-$ process including $\tau^+ \tau^-$ spin information in Pb-Pb ultraperipheral collision and at Lepton collider

TL;DR

This paper analyzes the $ au^+ au^-$ production in photon-photon collisions, including spin correlations and quantum entanglement, providing predictions for cross sections and spin states at NLO electroweak precision in collider environments.

Contribution

It introduces a detailed analysis of $ au^+ au^-$ spin correlations and quantum entanglement in photon-photon collisions, with NLO electroweak corrections, for the first time in this context.

Findings

NLO electroweak contributions are small for the observables considered.

Genuine quantum entanglement occurs near the $ au^+ au^-$ mass threshold.

Predictions for cross sections and spin correlations at high-energy colliders.

Abstract

We study the $\gamma\gamma \to \tau^+\tau^-$ process including full $\tau^+ \tau^-$ spin information in Pb--Pb ultraperipheral collision and at lepton colliders. We present the predictions for the corresponding cross sections and spin correlations at NLO electroweak precision, and find that the NLO electroweak contributions are numerically small for the observables considered. Additionally, we use the spin correlations obtained in this paper to analyze the quantum entanglement in the $\tau^+\tau^-$ system of the $\gamma\gamma \to \tau^+\tau^-$ process. Our results show that there is a genuine entangled configuration near the $\tau^+\tau^-$ invariant mass threshold. This work is helpful for studying the $\tau$-pair production induced by photon-photon collision at high energy colliders.