https://doi.org/10.1140/epja/i2002-10305-4
Study of baryon and search for dibaryon resonances by the 
reaction
1
Physikalisches Institut der Universität Tübingen, Morgenstelle 14, D-72076, Tübingen, Germany
2
The Svedberg Laboratory, S-751 21, Uppsala, Sweden
3
Department of Radiation Sciences, Uppsala University, S-751 21, Uppsala, Sweden
4
I. Institut für Experimentalphysik der Universität Hamburg, D-22761, Hamburg, Germany
5
IKP - Forschungszentrum Jülich GmbH, D-52425, Jülich, Germany
6
Joint Institute for Nuclear Research Dubna, 101000, Moscow, Russia
7
Soltan Institute for Nuclear Studies, PL-00681, Warsaw, Poland
8
Institute of Experimental Physics, Warsaw University, PL-0061, Warsaw, Poland
9
Soltan Institute for Nuclear Studies, PL-90137, Lódz, Poland
* e-mail: clement@pit.physik.uni-tuebingen.de
Exclusive measurements of the two-pion production channel have been carried out near threshold at CELSIUS with the PROMICE/WASA detector. They reveal 
as the dominant process at these energies, however, the data exhibit also significant contributions from 
. From the observed interference of these Roper decay routes their relative branching ratio is derived. The status on the search for NN-decoupled 
-resonances is reviewed with regard to recent experimental searches in the pionic double charge exchange in nuclei, the two-pion production in nucleon-nucleon collisions, the photo pion-production on the deuteron and the electro pion-production in nuclei.
© Società Italiana di Fisica and Springer-Verlag, 2003
