Optimal polarized observables for model-independent new-physics search at e+e- colliders

TL;DR

This paper investigates how polarized cross sections at future e+e- colliders can be used to set model-independent bounds on new four-fermion contact interactions, enhancing sensitivity and understanding of their chiral structure.

Contribution

It proposes an optimal method using polarized observables and kinematic cuts to improve sensitivity to contact interactions in e+e- collider processes.

Findings

Polarized cross sections can significantly improve bounds on contact interactions.

Optimal kinematic cuts enhance sensitivity to new physics.

Method allows model-independent analysis of chiral structures.

Abstract

For the processes e+e-\to \mu+\mu-, \tau+\tau-, b\bar{b} and c\bar{c} at a future e+e- collider with \sqrt{s}=0.5 TeV, we examine the sensitivity of the helicity cross sections to four-fermion contact interactions. If longitudinal polarization of the electron beam were available, two polarized integrated cross sections would offer the opportunity to separate the helicity cross sections and, in this way, to derive model-independent bounds on the relevant parameters. The measurement of these polarized cross sections with optimal kinematical cuts could significantly increase the sensitivity of helicity cross sections to contact interaction parameters and could give crucial information on the chiral structure of such new interactions.