First measurement of the polarization observable E in the p→(γ→, π+) n reaction up to 2.25 GeV.
Document Type
Article
Publication Date
2015
Abstract
First results from the longitudinally polarized frozen-spin target (FROST) program are reported. The double-polarization observable E, for the reaction , has been measured using a circularly polarized tagged-photon beam, with energies from 0.35 to 2.37 GeV. The final-state pions were detected with the CEBAF Large Acceptance Spectrometer in Hall B at the Thomas Jefferson National Accelerator Facility. These polarization data agree fairly well with previous partial-wave analyses at low photon energies. Over much of the covered energy range, however, significant deviations are observed, particularly in the high-energy region where high-L multipoles contribute. The data have been included in new multipole analyses resulting in updated nucleon resonance parameters. We report updated fits from the Bonn–Gatchina, Jülich–Bonn, and SAID groups.
Publication Title
Physics Letters B
Repository Citation
Strauch, Steffen; Briscoe, W. J.; Döring, M.; Klempt, E.; Nikonov, V. A.; Pasyuk, E.; Rönchen, D.; Biselli, Angela; and CLAS Collaboration, "First measurement of the polarization observable E in the p→(γ→, π+) n reaction up to 2.25 GeV." (2015). Physics Faculty Publications. 155.
https://digitalcommons.fairfield.edu/physics-facultypubs/155
Published Citation
Strauch, Steffen, W. J. Briscoe, M. Döring, E. Klempt, V. A. Nikonov, E. Pasyuk, D. Rönchen, Biselli A. et al [CLAS Collaboration]. "First measurement of the polarization observable E in the p→(γ→, π+) n reaction up to 2.25 GeV." Physics Letters B 750 (2015): 53-58. https://doi.org/10.1016/j.physletb.2015.08.053
DOI
10.1016/j.physletb.2015.08.053
Comments
© 2015 The Author(s)
Published by Elsevier B.V. under CC License Attribution 4.0 International (CC BY 4.0)