First results on nucleon resonance photocouplings from the $\gamma p \to \pi^+\pi^-p$ reaction

E. Golovatch , V.D. Burkert , D.S. Carman , R.W. Gothe , K. Hicks , B.S. Ishkhanov , V.I. Mokeev , E. Pasyuk , S. Adhikari , Z. Akbar , M.J. Amaryan , H. Avakian , J. Ball (1) , L. Barion , M. Bashkanov , M. Battaglieri , I. Bedlinskiy , A.S. Biselli , S. Boiarinov , W.J. Briscoe , F. Cao , A. Celentano , Pierre Chatagnon (2) , T. Chetry , G. Ciullo , L. Clark , B.A. Clary , P.L. Cole , M. Contalbrigo , V. Crede , A. d'Angelo , N. Dashyan , R. de Vita , E. de Sanctis , M. Defurne (1) , A. Deur , S. Diehl , C. Djalali , M. Dugger , R. Dupre (2) , H. Egiyan , Mathieu Ehrhart (2) , A. El Alaoui , L. El Fassi , L. Elouadrhiri , P. Eugenio , G. Fedotov , R. Fersch , A. Filippi , Y. Ghandilyan , G.P. Gilfoyle , K.L. Giovanetti , F.X. Girod (1) , D.I. Glazier , K.A. Griffioen , M. Guidal (2) , L. Guo , K. Hafidi , H. Hakobyan , N. Harrison , M. Hattawy , D. Heddle , M. Holtrop , Y. Ilieva , D.G. Ireland , E.L. Isupov , D. Jenkins , H.S. Jo (2) , S. Johnston , K. Joo , M.L. Kabir , D. Keller , G. Khachatryan , M. Khachatryan , M. Khandaker , W. Kim , A. Klein , F.J. Klein , V. Kubarovsky , L. Lanza , P. Lenisa , K. Livingston , I.J.D. Macgregor , D. Marchand (2) , N. Markov , B. Mckinnon , C.A. Meyer , R.A. Montgomery , A. Movsisyan , C. Munoz Camacho (2) , P. Nadel-Turonski , S. Niccolai (2) , G. Niculescu , M. Osipenko , A.I. Ostrovidov , M. Paolone , R. Paremuzyan , K. Park , O. Pogorelko , J.W. Price , Y. Prok , D. Protopopescu , M. Ripani , D. Riser , A. Rizzo , G. Rosner , F. Sabatié (1) , C. Salgado , R.A. Schumacher , Y.G. Sharabian , Iu. Skorodumina , G.D. Smith , D.I. Sober , D. Sokhan , N. Sparveris , I.I. Strakovsky , S. Strauch , M. Taiuti , J.A. Tan , N. Tyler , M. Ungaro , H. Voskanyan , E. Voutier (2) , R. Wang (2) , X. Wei , M.H. Wood , N. Zachariou , J. Zhang , Z.W. Zhao

1 DPHN - Département de Physique Nucléaire (ex SPhN)
2 IPNO - Institut de Physique Nucléaire d'Orsay

We report the first experimental measurements of the nine 1-fold differential cross sections for the γp→π+π−p reaction, obtained with the CLAS detector at Jefferson Laboratory. The measurements cover the invariant mass range of the final state hadrons from 1.6 GeV < W < 2.0 GeV. For the first time the photocouplings of all prominent nucleon resonances in this mass range have been extracted from this exclusive channel. Photoproduction of two charged pions is of particular importance for the evaluation of the photocouplings for the Δ(1620)1/2− , Δ(1700)3/2− , N(1720)3/2+ , and Δ(1905)5/2+ resonances, which have dominant decays into the ππN final states rather than the more extensively studied single meson decay channels.

Mots clés: Two pion photoproduction; Resonance photocouplings; Baryon state; hadron: final state; meson: decay; nucleon resonance; differential cross section: measured; pi: photoproduction; CLAS; photon: beam; experimental results; resonance: mass; cross section: angular dependence; photon p --> pi+ pi- p; B010.3; B010A1; B010A2; B010M; B010W; B011.3; B011A1; B011A2; B011M; B011W; B015.5; B015A1; B015A2; B015M; B015W; B065.5; B065A1; B065A2; B065M; B065W; B066.5; B066A1; B066M; B066W; B082.2; B082A1; B082M; B082W; B083.171; B083A1; B083A2; B083M; B083W

Domaines: Physique Nucléaire Expérimentale [nucl-ex]

E. Golovatch, V.D. Burkert, D.S. Carman, R.W. Gothe, K. Hicks, et al.. First results on nucleon resonance photocouplings from the $\gamma p \to \pi^+\pi^-p$ reaction. Phys.Lett.B, 2019, 788, pp.371-379. ⟨10.1016/j.physletb.2018.10.013⟩. ⟨hal-01823202⟩