@article{159d59fc684343ff93329b7e14fec301,
title = "Measurement of the helicity asymmetry e in ω→π+π-π0 photoproduction",
abstract = "The double-polarization observable E was studied for the reaction γp→pω using the CEBAF Large Acceptance Spectrometer (CLAS) in Hall B at the Thomas Jefferson National Accelerator Facility and the longitudinally polarized frozen-spin target (FROST). The observable was measured from the charged decay mode of the meson, ω→π+π-π0, using a circularly polarized tagged-photon beam with energies ranging from the ω threshold at 1.1 to 2.3 GeV. A partial-wave analysis within the Bonn-Gatchina framework found dominant contributions from the 3/2+ partial wave near threshold, which is identified with the subthreshold N(1720)3/2+ nucleon resonance. To describe the entire data set, which consisted of ω differential cross sections and a large variety of polarization observables, further contributions from other nucleon resonances were found to be necessary. With respect to nonresonant mechanisms, π exchange in the t channel was found to remain small across the analyzed energy range, while Pomeron t-channel exchange gradually grew from the reaction threshold to dominate all other contributions above W≈2 GeV.",
author = "{The CLAS Collaboration} and Z. Akbar and P. Roy and S. Park and V. Crede and Anisovich, {A. V.} and I. Denisenko and E. Klempt and Nikonov, {V. A.} and Sarantsev, {A. V.} and Adhikari, {K. P.} and S. Adhikari and Amaryan, {M. J.} and {Anefalos Pereira}, S. and H. Avakian and J. Ball and M. Battaglieri and V. Batourine and I. Bedlinskiy and S. Boiarinov and Briscoe, {W. J.} and J. Brock and Brooks, {W. K.} and Burkert, {V. D.} and Cao, {F. T.} and C. Carlin and Carman, {D. S.} and A. Celentano and G. Charles and T. Chetry and G. Ciullo and L. Clark and Cole, {P. L.} and M. Contalbrigo and O. Cortes and A. D'Angelo and N. Dashyan and {De Vita}, R. and {De Sanctis}, E. and A. Deur and C. Djalali and Michael Dugger and R. Dupre and H. Egiyan and {El Fassi}, L. and P. Eugenio and G. Fedotov and R. Fersch and A. Filippi and A. Fradi and Barry Ritchie",
note = "Funding Information: The authors thank the technical staff at Jefferson Lab and at all the participating institutions for their invaluable contributions to the success of the experiment. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, under Contract No. DE-AC05-06OR23177. This work was also supported by the U.S. National Science Foundation, the State Committee of Science of the Republic of Armenia, the Chilean Comisi{\'o}n Nacional de Investigaci{\'o}n Cient{\'i}fica y Tecnol{\'o}gica (CONICYT), the Italian Istituto Nazionale di Fisica Nucleare, the French Centre National de la Recherche Scientifique, the French Commissariat a l'Energie Atomique, the Scottish Universities Physics Alliance (SUPA), the United Kingdom's Science and Technology Facilities Council, the National Research Foundation of Korea, the Deutsche Forschungsgemeinschaft (SFB/TR110), and the Russian Science Foundation under Grant No. 16-12-10267. Publisher Copyright: {\textcopyright} 2017 American Physical Society.",
year = "2017",
month = dec,
day = "28",
doi = "10.1103/PhysRevC.96.065209",
language = "English (US)",
volume = "96",
journal = "Physical Review C",
issn = "2469-9985",
publisher = "American Physical Society",
number = "6",
}