The J/{\psi} {\omega} Decay Channel of the X(3872) Charm Meson Molecule

TL;DR

This paper investigates the decay channels of the X(3872) resonance, analyzing scattering effects and quantum number assignments, and finds that scattering does not significantly alter the observed decay distributions.

Contribution

It provides a detailed analysis of J/ψ ω decay channel and scattering effects, refining the quantum number assignment of X(3872) and modeling invariant mass distributions.

Findings

Quantum number 1^{++} is more probable than 2^{-+} after proper chi^2 evaluation.

Scattering effects do not significantly change the π+ π- π0 invariant mass distribution.

Analysis includes effects of charm meson scattering and the χ_{c1}(2P) resonance.

Abstract

Analyses of the J/{\psi} {\pi}+ {\pi}- decay channel of the X(3872) resonance by the CDF, Belle, and LHCb collaborations have established its J^{PC} quantum numbers as 1^{++}. An analysis of the \pi+ \pi- \pi 0 invariant mass distribution in the J/{\psi} \pi+ \pi- \pi 0 decay channel by the Babar collaboration indicated a preference for 2^{-+} over 1^{++}. We point out that a proper evaluation of the chi^2 in that analysis increases the probability for 1^{++} from 7.1% to about 18.7%. In the case of quantum numbers 1^{++}, where the X has an S-wave coupling to J/{\psi} {\omega}, the proximity of the J/{\psi} {\omega} threshold to D^* Dbar thresholds and the narrow width of the {\omega} suggest that the effects of scattering between J/{\psi} {\omega} and charm meson pairs could be significant. We derive invariant mass distributions for J/{\psi} \pi+ \pi- and \pi+ \pi- \pi 0 that take into account S-wave scattering between the D^{*0} Dbar^0, D^{*+} D^-, and J/{\psi} {\omega} channels. We also analyze the effects of scattering through the chi_{c1}(2P) charmonium resonance. We find that scattering effects are unable to produce significant changes in the shape of the \pi+ \pi- {\pi} 0 invariant mass distribution.