I = 0 C = +1 mesons from 1920 to 2410 MeV

TL;DR

This study performs a comprehensive fit to pbar-p annihilation data, revealing new meson resonances and refining properties of known states, supporting quark model trajectories in the 1920-2410 MeV range.

Contribution

It introduces a combined analysis of multiple final states at various momenta, identifying new resonances and improving parameter estimates for meson states in this energy range.

Findings

Discovery of new meson resonances with specific masses and widths.

Refined measurements of existing meson state parameters.

Evidence supporting meson trajectories aligned with quark model predictions.

Abstract

A combined fit is presented to data on pbar-p annihilation in flight to final states eta-pizero-pizero, pizero-pizero, eta-eta, eta-etaprime and piminus-piplus. The emphasis lies in improving an earlier study of eta-pizero-pizero by fitting data at nine pbar momenta simultaneously and with parameters consistent with the two-body channels. There is evidence for all of the I=0, C=+ q-qbar states expected in this mass range. New resonances are reported with masses and widths M,Gamma as follows: JPC = 4^{-+} (2328+-38, Gamma=240+-90) MeV, 1^{++} (1971+-15, 240+-45) MeV, 0^{-+} (2285+-20, 325+-30) MeV, and 0^{-+} (2010 ^{+35}_{-60}, 270+-60) MeV. Errors on the masses and widths of other resonances are also reduced substantially. All states lie close to parallel straight line trajectories of excitation number v. mass squared.