Possible Indication of Narrow Baryonic Resonances Produced in the 1720-1790 MeV Mass Region

Abstract

Signals of two narrow structures at M = 1747 and 1772 MeV were observed in the invariant masses M p X and M π+ X of the pp \rightarrow ppX and pp \rightarrow p \pi ^{ + }X reactions, respectively. Many tests were made to see if experimental artefacts could have produced these structures. Their small widths and the stability of the extracted masses lead us to conclude that these structures are genuine and may correspond to new exotic baryons. Several attempts to identify them, including the possible “missing baryons” approach, are discussed.