Beam–target helicity asymmetry E in K+Σ− photoproduction on the neutron

Zachariou, N.; Watts, D. P.; Fleming, J.; Sarantsev, A. V.; Nikonov, V. A.; D'Angelo, A.; Bashkanov, M.; Hanretty, C.; Kageya, T.; Klein, F. J.; Lowry, M.; Lu, H.; Sandorfi, A.; Wei, X.; Zonta, I.; Adhikari, K. P.; Adhikari, S.; Amaryan, M. J.; Angelini, G.; Asryan, G.; Atac, H.; Barion, L.; Bass, C.; Battaglieri, M.; Bedlinskiy, I.; Benmokhtar, F.; Bianconi, A.; Biselli, A. S.; Bossu, F.; Boiarinov, S.; Briscoe, W. J.; Brooks, W. K.; Bulumulla, D.; Burkert, V.; Carman, D. S.; Carvajal, J. C.; Celentano, A.; Charles, G.; Chatagnon, P.; Chetry, T.; Ciullo, G.; Cole, P. L.; Contalbrigo, M.; Dashyan, N.; De Vita, R.; Deur, A.; Diehl, S.; Djalali, C.; Dupre, R.; Egiyan, H.; Ehrhart, M.; El Alaoui, A.; Eugenio, P.; Fegan, S.; Fersch, R.; Filippi, A.; Gavalian, G.; Gevorgyan, N.; Ghandilyan, Y.; Gilfoyle, G. P.; Girod, F. X.; Gohn, W.; Golovatch, E.; Gothe, R. W.; Griffioen, K. A.; Guidal, M.; Hafidi, K.; Hakobyan, H.; Hattawy, M.; Heddle, D.; Hicks, K.; Ho, D.; Holtrop, M.; Ilieva, Y.; Ireland, D. G.; Ishkhanov, B. S.; Isupov, E. L.; Jenkins, D.; H. S., Jo; Joo, K.; Joosten, S. J.; Keller, D.; Khachatryan, M.; Khanal, A.; Khandaker, M.; Kim, C. W.; Kim, W.; Kubarovsky, V.; Lanza, L.; Leali, M.; Lenisa, P.; Livingston, K.; Macgregor, I. J. D.; Marchand, D.; Markov, N.; Marsicano, L.; Mascagna, V.; Mayer, M.; Mckinnon, B.; Meziani, Z. E.; Mineeva, T.; Mokeev, V.; Munevar, E.; Munoz Camacho, C.; Nadel Turonski, P.; O'Connell, T. R.; Osipenko, M.; Ostrovidov, A. I.; Paolone, M.; Pappalardo, L. L.; Park, K.; Pasyuk, E.; Peng, P.; Phelps, W.; Pogorelko, O.; Poudel, J.; Price, J. W.; Prok, Y.; Puckett, A. J. R.; Raue, B. A.; Ripani, M.; Rizzo, A.; Rosner, G.; Salgado, C.; Schmidt, A.; Schumacher, R. A.; Shrestha, U.; Sokhan, D.; Soto, O.; Sparveris, N.; Strakovsky, I. I.; Strauch, S.; Tan, J. A.; Tyler, N.; Ungaro, M.; Venturelli, L.; Voskanyan, H.; Voutier, E.; Walford, N. K.; Whisnant, C. S.; Wood, M. H.; Zhang, J.; Zhao, Z. W.

doi:10.1016/j.physletb.2020.135662

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)3/2javax.xml.bind.JAXBElement@138a3a1d resonance, are also quantified.