Evidence for a New Resonance from Polarized Neutron-Proton Scattering
2014 (English)In: Physical Review Letters, ISSN 0031-9007, Vol. 112, no 20, 202301- p.Article in journal (Refereed) Published
Exclusive and kinematically complete high-statistics measurements of quasifree polarized (n) over right arrowp scattering have been performed in the energy region of the narrow resonancelike structure d* with I(J(P)) = 0(3(+)),M approximate to 2380 MeV, and Gamma approximate to 70 MeV observed recently in the double-pionic fusion channels pn -> d pi(0)pi(0) and pn -> d pi(+)pi(-). The experiment was carried out with the WASA detector setup at COSY having a polarized deuteron beam impinged on the hydrogen pellet target and utilizing the quasifree process (d) over right arrowp -> np + p(spectator). This allowed the np analyzing power, A(y), to be measured over a broad angular range. The obtained A(y) angular distributions deviate systematically from the current SAID SP07 NN partial-wave solution. Incorporating the new A(y) data into the SAID analysis produces a pole in the D-3(3) - (3)G(3) waves in support of the d* resonance hypothesis.
Place, publisher, year, edition, pages
2014. Vol. 112, no 20, 202301- p.
IdentifiersURN: urn:nbn:se:uu:diva-228474DOI: 10.1103/PhysRevLett.112.202301ISI: 000336914800003OAI: oai:DiVA.org:uu-228474DiVA: diva2:734239