Neutron-proton scattering in the context of the d∗ (2380) resonance

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 3D3-3G3 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 Td=2.27 GeV is discussed. © 2014 American Physical Society.