Two-particle kinematic distributions from new physics at an electron-positron collider with polarized beams

TL;DR

This paper derives model-independent two-particle kinematic distributions at electron-positron colliders with polarized beams, enabling analysis of new physics interactions beyond the standard model through angular and polarization measurements.

Contribution

It provides a comprehensive, model-independent framework for analyzing two-particle distributions including polarization effects, extending previous methods to new physics scenarios.

Findings

Distributions can reveal properties of new physics interactions.

Polarization enhances sensitivity to new physics signatures.

Application to Higgs and fermion pair final states demonstrates practical utility.

Abstract

The kinematic distributions in two-particle inclusive processes at an e+e- collider arising from standard-model s-channel exchange of a virtual gamma or Z and the interference of the standard-model contribution with contributions from physics beyond the standard model involving s-channel exchanges are derived entirely in terms of the space-time signature of such new physics. Transverse as well as longitudinal polarizations of the electron and positron beams are taken into account. We show how these model-independent distributions can be used to deduce some general properties of the nature of the interaction. We then specialize to two specific two-particle final states, viz., ZH, where H is one of the Higgs bosons in a model with an extended Higgs sector, and f fbar, where f, fbar are a pair of conjugate charged fermions, wherein distributions of two (of the possibly several) decay products are measured. We show how some of the properties of the distributions have been realized in the analysis of physics beyond the standard model in earlier work which made use of two-particle angular distributions.