Concavity of the meson Regge trajectories

TL;DR

This paper demonstrates that meson Regge trajectories are predominantly concave, providing a model-independent criterion for meson classification and guiding the development of theoretical models of meson spectra.

Contribution

It establishes the concavity of meson Regge trajectories as a universal, model-independent feature and proposes it as a criterion for meson classification and model construction.

Findings

Most meson Regge trajectories are concave.

Concavity can help classify newly observed mesons.

Existing models may need correction to produce concave trajectories.

Abstract

It is illustrated by the fitted Regge trajectories for a large majority of mesons that both the radial and orbital Regge trajectories for mesons prefer being concave. The concavity of the meson Regge trajectories is model-independent. If the convex Regge trajectories or the Regge trajectories having the inflection points do not exist, the concavity can act as a criterion to choose a newly observed meson or to assign a particle to the unwell-established state. The curvature of the meson Regge trajectories can be taken as a guide in constructing models. The appropriate models should yield the spectra which can produce the concave Regge trajectories according to the concavity of the meson Regge trajectories. If the large majority of the meson Regge trajectories are concave while a few meson Regge trajectories are convex which neither have been confirmed nor have been completely excluded at present, many existing models should be corrected or even be reconstructed, which will lead to the further understanding of the meson dynamics.