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Title: First measurement of the helicity asymmetry E in η photoproduction on the proton

Journal Article · · Physics Letters. B
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Results are presented for the first measurement of the double-polarization helicity asymmetry E for the η photoproduction reaction γ p → ηp. Data were obtained using the FROzen Spin Target (FROST) with the CLAS spectrometer in Hall B at Jefferson Lab, covering a range of center-of-mass energy W from threshold to 2.15 GeV and a large range in center-of-mass polar angle. As an initial application of these data, the results have been incorporated into the Jülich–Bonn model to examine the case for the existence of a narrow N* resonance between 1.66 and 1.70 GeV. The addition of these data to the world database results in marked changes in the predictions for the E observable from that model. Further comparison with several theoretical approaches indicates these data will significantly enhance our understanding of nucleon resonances.

Research Organization:
Argonne National Laboratory (ANL), Argonne, IL (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Nuclear Physics (NP); National Science Foundation (NSF); Instituto Nazionale di Fisica Nucleare (INFN)
DOE Contract Number:
AC02-06CH11357
OSTI ID:
1344931
Journal Information:
Physics Letters. B, Vol. 755, Issue C; ISSN 0370-2693
Publisher:
Elsevier
Country of Publication:
United States
Language:
English

References (31)

Baryon spectroscopy journal April 2010
Exotic anti-decuplet of baryons: prediction from chiral solitons journal September 1997
Where are the missing members of the baryon antidecuplet? journal May 2004
Nonstrange and other flavor partners of the exotic Θ + baryon journal March 2004
Study of the narrow structure at 1685 MeV in γ p η p journal February 2013
Narrow Structure in the Excitation Function of η Photoproduction off the Neutron journal December 2013
Evidence for narrow resonant structures at W 1.68 GeV and W 1.72 GeV in real Compton scattering off the proton journal April 2015
Beam-Helicity Asymmetries in Double-Charged-Pion Photoproduction on the Proton journal October 2005
First Measurement of the Helicity Asymmetry for γ p p π 0 in the Resonance Region journal January 2014
Beam-Helicity Asymmetries in Double-Pion Photoproduction off the Proton journal July 2009
Helicity Beam Asymmetry I☉ in Two Neutral Pseudoscalar Photoproduction Reactions at the Crystal Barrel Experiment
  • Wilson, Andrew; Crede, Volker; Eugenio, Paul
  • HADRON 2009: Proceedings of the XIII International Conference on Hadron Spectroscopy, AIP Conference Proceedings https://doi.org/10.1063/1.3483404
conference January 2010
Measurement of the beam-helicity asymmetry I⊙ in the photoproduction of $ \pi^{0}$ $ \pi^{\pm}$ pairs off protons and off neutrons journal March 2014
The CEBAF large acceptance spectrometer (CLAS)
  • Mecking, B. A.; Adams, G.; Ahmad, S.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 503, Issue 3 https://doi.org/10.1016/S0168-9002(03)01001-5
journal May 2003
The bremsstrahlung tagged photon beam in Hall B at JLab
  • Sober, D. I.; Crannell, Hall; Longhi, Alberto
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 440, Issue 2 https://doi.org/10.1016/S0168-9002(99)00784-6
journal February 2000
The Jefferson Lab frozen spin target
  • Keith, C. D.; Brock, J.; Carlin, C.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 684 https://doi.org/10.1016/j.nima.2012.04.067
journal August 2012
The CLAS drift chamber system
  • Mestayer, M. D.; Carman, D. S.; Asavapibhop, B.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 449, Issue 1-2 https://doi.org/10.1016/S0168-9002(00)00151-0
journal July 2000
The time-of-flight system for CLAS
  • Smith, E. S.; Carstens, T.; Distelbrink, J.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 432, Issue 2-3 https://doi.org/10.1016/S0168-9002(99)00484-2
journal August 1999
A new highly segmented start counter for the CLAS detector
  • Sharabian, Y. G.; Battaglieri, M.; Burkert, V. D.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 556, Issue 1 https://doi.org/10.1016/j.nima.2005.10.031
journal January 2006
Near threshold photoproduction of η mesons from 4 He journal September 1999
Experimental study of the γ p η p reaction with the Crystal Ball detector at the Mainz Microtron (MAMI-C) journal September 2010
Eta photoproduction in a combined analysis of pion- and photon-induced reactions journal June 2015
Nucleon resonances within a dynamical coupled-channels model of π N and γ N reactions journal September 2013
Coupled-channel dynamics in the reactions πN → πN, ηN, KΛ, KΣ journal April 2013
Parameterization dependence of T -matrix poles and eigenphases from a fit to π N elastic scattering data journal September 2012
Photocouplings at the pole from pion photoproduction journal June 2014
Erratum to: Photocouplings at the pole from pion photoproduction journal May 2015
Measurement of the Transverse Target and Beam-Target Asymmetries in η Meson Photoproduction at MAMI journal September 2014
Photon and Electron Polarization in High-Energy Bremsstrahlung and Pair Production with Screening journal May 1959
Nucleon resonances within a dynamical coupled-channels model of pi N and gamma N reactions text January 2013
SU(3) breaking in decays of exotic baryons text January 2004
Exotic Anti-Decuplet of Baryons: Prediction from Chiral Solitons text January 1997

Cited By (4)

The impact of $K^{+}\Lambda$ K + Λ photoproduction on the resonance spectrum journal June 2018
η and η mesons with connection to anomalous glue journal February 2019
Complete basis for the pentaquark wave function in a group theory approach journal December 2019
Covariance Matrix for Helicity Couplings journal April 2018

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