New Excitation Mode of the Nucleon?

Abstract

We consider properties of narrow baryon states observed recently in reaction $pp\to p\pi^+X$. Two lowest of them (with mass 1004 and 1044 MeV, respectively) are stable against strog decay. Moreover we conclude that they cannot decay to $\gamma N$ and thus this states are a kind of metastable levels in quark system. The simplest decay channel is assumed to be $2\gamma N$ and possible quark configuration with such properties is discussed. New experiment for verification of status of this states in $\gamma N$ collision is proposed.