The determination of the spin and parity of a vector-vector system

TL;DR

This paper introduces a model-independent method to determine the spin and parity of a resonance decaying into two identical vector particles, demonstrated through Higgs decay and J/psi pair production.

Contribution

It presents a new construction of the reaction amplitude that allows for model-independent determination of resonance quantum numbers.

Findings

Method successfully applied to Higgs decay to four leptons

Angular correlations used to analyze J/psi pair production

Provides a general framework for resonance quantum number determination

Abstract

We present a construction of the reaction amplitude for the inclusive production of a resonance decaying to a pair of identical vector particles such as $J/\psi J/\psi$, $\rho\rho$, $\phi\phi$. The method provides the possibility of determining the spin and parity of a resonance in a model-independent way. The methodology is demonstrated using the Standard Model decay of the Higgs boson to four leptons and through angular correlations in the production and decays of $J/\psi$ pairs.