The Nature of the X(2175)

TL;DR

This paper investigates the nature of the X(2175) meson using an advanced multichannel model that includes various coupled channels, revealing dynamically generated poles near the X(2175) energy region.

Contribution

It extends the Resonance-Spectrum-Expansion model to include additional S-wave channels, providing a new explanation for the X(2175) as a dynamically generated state.

Findings

Identified poles near the X(2175) energy region at 2.037-i0.170 GeV and 2.382-i0.20 GeV.

Demonstrated the importance of S-wave channels in the resonance's structure.

Proposed further model improvements for better understanding.

Abstract

We study the puzzling vector meson X(2175) in a multichannel generalisation of the Resonance-Spectrum-Expansion model. Besides the usual P-wave pseudoscalar-pseudoscalar, pseudoscalar-vector, and vector-vector channels that couple to mesons with vector quantum numbers, we also include the important S-wave vector-scalar, pseudoscalar-axialvector and vector-axialvector channels, including the observed $\phi$(1020)$f_0$(980) decay mode. The strong coupling to nearby S-wave channels originates dynamically generated poles, two of which come out close to the energy region of the X(2175), viz. at (2.037-i0.170) GeV and (2.382-i0.20) GeV. Further improvements are proposed.