| 1. |
- Adlarson, Patrik, et al.
(författare)
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Measurement of the eta -> pi(+)pi(-)pi(0) Dalitz plot distribution
- 2014
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Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 90:4, s. 045207-
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Tidskriftsartikel (refereegranskat)abstract
- The Dalitz plot distribution of the eta -> pi(+)pi(-)pi(0) decay is determined by using a data sample of 1.2 x 10(7) eta mesons from the pd -> He-3 eta reaction at 1 GeV collected by the WASA detector at COSY.
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| 2. |
- Adlarson, Patrik, et al.
(författare)
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Charge symmetry breaking in dd -> He-4 pi(0) with WASA-at-COSY
- 2014
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Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 739, s. 44-49
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Tidskriftsartikel (refereegranskat)abstract
- Charge symmetry breaking (CSB) observables are a suitable experimental tool to examine effects induced by quark masses on the nuclear level. Previous high precision data from TRIUMF and IUCF are currently used to develop a consistent description of CSB within the framework of chiral perturbation theory. In this work the experimental studies on the reaction dd -> He-4 pi(0) have been extended towards higher excess energies in order to provide information on the contribution of p-waves in the final state. For this, an exclusive measurement has been carried out at a beam momentum of p(d) = 1.2GeV/c using the WASA-at-COSY facility. The total cross section amounts to sigma(tot) =(118 +/- 18(stat) +/- 13(sys) +/- 8(ext)) p band first data on the differential cross section are consistent with s-wave pion production.
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| 3. |
- Adlarson, Patrik, et al.
(författare)
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Cross section ratio and angular distributions of the reaction p + d -> He-3 + eta at 48.8MeV and 59.8MeV excess energy
- 2014
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Ingår i: European Physical Journal A. - : Springer Science and Business Media LLC. - 1434-6001 .- 1434-601X. ; 50:6, s. 100-
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Tidskriftsartikel (refereegranskat)abstract
- We present new data for angular distributions and on the cross section ratio of the p+d -> He-3+eta reaction at excess energies of Q - 48.8MeV and Q - 59.8 MeV. The data have been obtained at the WASA-at-COSY experiment (Forschungszentrum Julich) using a proton beam and a deuterium pellet target. While the shape of obtained angular distributions show only a slow variation with the energy, the new results indicate a distinct and unexpected total cross section fluctuation between Q = 20MeV and Q = 60 MeV, which might indicate the variation of the production mechanism within this energy interval.
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| 4. |
- Adlarson, Patrik, et al.
(författare)
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Neutron-proton scattering in the context of the d*(2380) resonance
- 2014
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Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 90:3, s. 035204-
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Tidskriftsartikel (refereegranskat)abstract
- New data on quasifree polarized neutron-proton scattering in the region of the recently observed d* resonance structure are obtained by exclusive and kinematically complete high-statistics measurements with WASA at COSY. This paper details the determination of the beam polarization, checks of the quasifree character of the scattering process, on all obtained Ay angular distributions and on the new partial-wave analysis, which includes the new data producing a resonance pole in D-3(3)-(3)G(3) coupled partial waves at (2380 +/- 10 - i40 +/- 5) MeV-in accordance with the d* dibaryon resonance hypothesis. The effect of the new partial-wave solution on the description of total and differential cross-section data as well as specific combinations of spin-correlation and spin-transfer observables available from COSY-ANKE measurements at T-d = 2.27 GeV is discussed.
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| 5. |
- Adlarson, Patrik, et al.
(författare)
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Evidence for a New Resonance from Polarized Neutron-Proton Scattering
- 2014
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 112:20, s. 202301-
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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