Physics Letters B
We report a measurement of a beam-target double-polarisation observable (E) for the 𝛾→ n→(p) → K+Σ-(p) reaction. The data were obtained impinging the circularly-polarised energy-tagged photon beam of Hall B at Jefferson Lab on a longitudinally-polarised frozen-spin hydrogen deuteride (HD) nuclear target. The E observable for an effective neutron target was determined for centre-of-mass energies 1.70 ≤ W ≤ 2.30 GeV, with reaction products detected over a wide angular acceptance by the CLAS spectrometer. These new double-polarisation data give unique constraints on the strange decays of excited neutron states. Inclusion of the new data within the Bonn-Gatchina theoretical model results in significant changes for the extracted photocouplings of a number of established nucleon resonances. Possible improvements in the PWA description of the experimental data with additional "missing" resonance states, including the N(2120)3/2- resonance, are also quantified.
Original Publication Citation
Zachariou, N., Adhikari, K.P., Khachatryan, M., Mayer, M., Prok, Y., et al., CLAS Collaboration (2020). Beam-target helicity asymmetry E in K+Σ- photoproduction on the neutron. Physics Letters B, 808, 7 pp., Article 135662. https://doi.org/10.1016/j.physletb.2020.135662
Zachariou, N.; Adhikari, K. P.; Khachatryan, M.; Mayer, M.; Prok, Y.; Et al.; and CLAS Collaboration, "Beam-Target Helicity Asymmetry E in K⁺Σ⁻ Photoproduction On The Neutron" (2020). Physics Faculty Publications. 443.