TITLE

Excitation of the Roper resonance in single- and double-pion production in nucleon-nucleon collisions⋆

AUTHOR(S)
Skorodko, T.; Bashkanov, M.; Bogoslawsky, D.; Calen, H.; Cappellaro, F.; Clement, H.; Demiroers, L.; Doroshkevich, E.; Duniec, D.; Ekström, C.; Franssen, K.; Gustafsson, L.; Höistad, B.; Ivanov, G.; Jacewicz, M.; Jiganov, E.; Johansson, T.; Khakimova, O.; Kaskulov, M.; Keleta, S.
PUB. DATE
March 2008
SOURCE
European Physical Journal A -- Hadrons & Nuclei;Mar2008, Vol. 35 Issue 3, p317
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
In most investigations the Roper resonance is sensed only very indirectly via complex partial-wave analyses. We find indications for its excitation in the invariant nπ+ mass spectrum of the pp → npπ+ reaction at M ≈ 1360 MeV with a width of ≈ 150 MeV . The values fit very favorably to the most recent phase shift results as well as to the observations at BES. In the near-threshold two-pion production pp → ppπ0π0 , where the Roper excitation and its subsequent decays via the routes N * → Δπ → Nππ and N * → Nσ are the only dominant processes, we find its direct decay into the Nσ channel to be the by far dominating decay process --in favor of a monopole excitation of the Roper resonance.
ACCESSION #
31695134

 

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