Excitation of the Roper resonance in single- and double-pion production in nucleon-nucleon collisions
2008 (English)In: European Physical Journal A, ISSN 1434-6001, E-ISSN 1434-601X, Vol. 35, no 3, 317-319 p.Article in journal (Refereed) Published
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 n pi(+) mass spectrum of the pp -> np pi(+) reaction at M approximate to 1360 MeV with a width of approximate to 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 -> pp pi(0)pi(0) , where the Roper excitation and its subsequent decays via the routes N* -> Delta pi -> N pi pi and N* -> N sigma are the only dominant processes, we find its direct decay into the N sigma channel to be the by far dominating decay process -in favor of a monopole excitation of the Roper resonance.
Place, publisher, year, edition, pages
2008. Vol. 35, no 3, 317-319 p.
IdentifiersURN: urn:nbn:se:uu:diva-149847DOI: 10.1140/epja/i2008-10569-6ISI: 000255095800013OAI: oai:DiVA.org:uu-149847DiVA: diva2:405928