Decay-lepton correlations as probes of anomalous ZZH and gammaZH interactions in e+e- --> ZH with polarized beams

TL;DR

This paper investigates how polarized beams in e+e- collisions can be used to detect and distinguish anomalous ZZH and gammaZH interactions, enhancing sensitivity and enabling independent measurement of certain couplings.

Contribution

It introduces a method using beam polarization and simple observables to disentangle and measure anomalous couplings in Higgs production processes.

Findings

Longitudinal polarization improves coupling sensitivity.

Transverse polarization allows independent measurement of gammaZH coupling.

Certain observables can isolate specific anomalous couplings.

Abstract

We examine the contributions of various couplings in general ZZH and gammaZH interactions arising from new physics to the Higgs production process e+e- --> HZ, followed by the decay of the Z into a charged-lepton pair. We take into account possible longitudinal or transverse beam polarization likely to be available at a linear collider. We show how expectation values of certain simple observables in suitable combinations with appropriate longitudinal beam polarizations can be used to disentangle various couplings from one another. Longitudinal polarization can also improve the sensitivity for measurement of several couplings. A striking result is that using transverse polarization, one of the gammaZH couplings, not otherwise accessible, can be determined independently of all other couplings.