Search for excited spin-3/2 and spin-1/2 leptons at linear colliders

TL;DR

This paper investigates the potential to detect excited spin-3/2 and spin-1/2 leptons at future high-energy electron-positron colliders by calculating production rates, decay properties, and distinguishing features based on angular distributions.

Contribution

It provides a detailed analysis of production cross sections, decay widths, and angular distributions for excited leptons, offering new methods to identify their spin states at linear colliders.

Findings

Excited leptons can be probed up to masses near the collider energy.

Angular distributions help distinguish between spin-3/2 and spin-1/2 states.

Estimated limits on masses and couplings for future collider experiments.

Abstract

We study the single production of excited spin-3/2 and spin-1/2 leptons in future high energy $e^+e^-$ collisions. We calculate the production cross section and decay widths of excited spin-3/2 and spin-1/2 leptons according to their effective currents. We show that these possible new excited states can be probed up to the mass $m^*$ ~ $\sqrt{s}$ depending on their couplings to leptons and gauge bosons. We present the angular distributions of final state particles as a measure to discriminate between an excited spin-3/2 and spin-1/2 lepton signal. The signals and the corresponding backgrounds are studied in detail to obtain attainable limits on masses and couplings of excited leptons at future linear colliders