Beam–target helicity asymmetry $E$ in $K^+$ $\Sigma^-$ photoproduction on the neutron

N. Zachariou , D.P. Watts , J. Fleming , A.V. Sarantsev , V.A. Nikonov , A. d'Angelo , M. Bashkanov , C. Hanretty , T. Kageya , F.J. Klein , M. Lowry , H. Lu , A. Sandorfi , X. Wei , I. Zonta , K.P. Adhikari , S. Adhikari , M.J. Amaryan , G. Angelini , G. Asryan , H. Atac , L. Barion , C. Bass , M. Battaglieri , I. Bedlinskiy , F. Benmokhtar , A. Bianconi , A.S. Biselli , F. Bossù (1) , S. Boiarinov , W.J. Briscoe , W.K. Brooks , D. Bulumulla , V. Burkert , D.S. Carman , J.C. Carvajal , A. Celentano , G. Charles (1) , P. Chatagnon (2) , T. Chetry , G. Ciullo , P.L. Cole , M. Contalbrigo , N. Dashyan , R. de Vita , A. Deur , S. Diehl , C. Djalali , R. Dupre (2, 1) , H. Egiyan , M. Ehrhart , A. El Alaoui , P. Eugenio , S. Fegan , R. Fersch , A. Filippi , G. Gavalian , N. Gevorgyan , Y. Ghandilyan , G.P. Gilfoyle , F.X. Girod , W. Gohn , E. Golovatch , R.W. Gothe , K.A. Griffioen , M. Guidal (2) , K. Hafidi , H. Hakobyan , M. Hattawy , D. Heddle , K. Hicks , D. Ho , M. Holtrop , Y. Ilieva , D.G. Ireland , B.S. Ishkhanov , E.L. Isupov , D. Jenkins , H.S. Jo (2) , K. Joo , S.J. Joosten , D. Keller , M. Khachatryan , A. Khanal , M. Khandaker , C.W. Kim , W. Kim , V. Kubarovsky , L. Lanza , M. Leali , P. Lenisa , K. Livingston , I.J.D. Macgregor , D. Marchand (2) , N. Markov , L. Marsicano , V. Mascagna , M. Mayer , B. Mckinnon , Z.E. Meziani , T. Mineeva , V. Mokeev , E. Munevar , C. Munoz Camacho (2) , P. Nadel Turonski , T.R. O'Connell , M. Osipenko , A.I. Ostrovidov , M. Paolone , L.L. Pappalardo , K. Park , E. Pasyuk , P. Peng , W. Phelps , O. Pogorelko , J. Poudel , J.W. Price , Y. Prok , A.J.R. Puckett , B.A. Raue , M. Ripani , A. Rizzo , G. Rosner , C. Salgado , A. Schmidt , R.A. Schumacher , U. Shrestha , D. Sokhan (2) , O. Soto , N. Sparveris , I.I. Strakovsky , S. Strauch , J.A. Tan , N. Tyler , M. Ungaro , L. Venturelli , H. Voskanyan , E. Voutier (2) , N.K. Walford , C.S. Whisnant , M.H. Wood , J. Zhang , Z.W. Zhao

1 IRFU - Institut de Recherches sur les lois Fondamentales de l'Univers
2 IJCLab - Laboratoire de Physique des 2 Infinis Irène Joliot-Curie

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.

Mots clés: Sigma-: photoproduction; K+: photoproduction; n: target; helicity: asymmetry; nucleus: target; photon: beam; nucleon resonance; Jefferson Lab; spectrometer; CLAS; experimental results

Domaines: Physique Nucléaire Expérimentale [nucl-ex]

N. Zachariou, D.P. Watts, J. Fleming, A.V. Sarantsev, V.A. Nikonov, et al.. Beam–target helicity asymmetry $E$ in $K^+$ $\Sigma^-$ photoproduction on the neutron. Phys.Lett.B, 2020, 808, pp.135662. ⟨10.1016/j.physletb.2020.135662⟩. ⟨hal-02917260⟩