Recently, several papers discussed on the existence of a low mass new structure
at a mass close to M=214.3~MeV. It was suggested that the $\\Sigma^{+}$ disintegration:
$\\Sigma^{+}\\to$pP$^{0}$, P$^{0}\\to\\mu^{-}\\mu^{+}$ proceeds through an
intermediate particle P$^{0}$ having such mass.
The present work intends to look at other new or available data, in order to observe
the eventual existence of small narrow peaks or shoulders in very low mesonic masses.
Indeed narrow structures were already extracted from various data in dibaryons, baryons
and mesons (at larger masses that those studied here). |
