Analysis of the Quantum Numbers $J^{PC}$ of the X(3872) Particle

TL;DR

This paper analyzes the angular distributions of the X(3872) particle's decay products to determine its quantum numbers, concluding that JPC = 1++ or 2-+ are consistent with experimental data.

Contribution

It provides the first detailed angular distribution analysis to constrain the quantum numbers of X(3872) using collider data.

Findings

JPC = 1++ is consistent with data

JPC = 2-+ is consistent with data

Other JPC hypotheses are excluded

Abstract

We present an analysis of angular distributions and correlations of the X(3872) particle in the exclusive decay mode X(3872)->J/psi pi+ pi- with J/psi->mu+ mu-. We use 780 pb -1 of data from ppbar collisions at sqrt{s} = 1.96 TeV collected with the CDF II detector at the Fermilab Tevatron. We derive constraints on spin, parity, and charge conjugation parity of the X(3872) particle by comparing measured angular distributions of the decay products with predictions for different JPC hypotheses. The assignments JPC = 1++ and 2-+ are the only ones consistent with the data.