Abstract
Mapping states with explicit gluonic degrees of freedom in the light sector is a challenge, and has led to controversies in the past. In particular, the experiments have reported two different hybrid candidates with spin-exotic signature, and , which couple separately to and . This picture is not compatible with recent Lattice QCD estimates for hybrid states, nor with most phenomenological models. We consider the recent partial wave analysis of the system by the COMPASS Collaboration. We fit the extracted intensities and phases with a coupled-channel amplitude that enforces the unitarity and analyticity of the matrix. We provide a robust extraction of a single exotic resonant pole, with mass and width and , which couples to both channels. We find no evidence for a second exotic state. We also provide the resonance parameters of the and .
- Received 13 October 2018
- Revised 19 November 2018
DOI:https://doi.org/10.1103/PhysRevLett.122.042002
Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP3.
Published by the American Physical Society