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Title: Coherent π{sup 0}-photoproduction on the deuteron near the η-production threshold including polarization observables

Abstract

Coherent π{sup 0}-photoproduction on the deuteron including polarization observables is studied in the energy region near the η-production threshold at backward center-of-mass angles of the outgoing pion. This work is motivated by the measurements of the CLAS Collaboration at Jefferson Lab, where a cusp-like structure in the energy dependence of the differential cross section has been observed at extremely backward pion angles. The present approach is based on the impulse approximation and first-order rescattering diagrams with intermediate production of both π- and η-mesons. Numerical results for unpolarized cross sections, the linear photon asymmetry (Σ), the vector (T{sub 11}) and tensor (T{sub 2M}, M=0, 1, 2) deuteron target asymmetries, and the double polarization E-asymmetry are predicted and compared with available experimental data and other theoretical models. The effect of first-order rescattering is found to be much larger in spin asymmetries than in the unpolarized cross sections. It reaches on average about 40% in the tensor target and E asymmetries. Compared to the experimental data from CLAS Collaboration, sizable discrepancies are found. This is not the case for the linear photon asymmetry, for which a better comparison with the data from YerPhI Collaboration is obtained.

Authors:
 [1]
  1. Physics Department, Faculty of Science, Qassim University, Buraydah 51452, P.O. Box 6644 (Saudi Arabia)
Publication Date:
OSTI Identifier:
22403459
Resource Type:
Journal Article
Journal Name:
Annals of Physics (New York)
Additional Journal Information:
Journal Volume: 351; Other Information: Copyright (c) 2014 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0003-4916
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ASYMMETRY; CEBAF ACCELERATOR; CENTER-OF-MASS SYSTEM; CUSPED GEOMETRIES; DEUTERIUM TARGET; DIFFERENTIAL CROSS SECTIONS; ENERGY DEPENDENCE; EXPERIMENTAL DATA; IMPULSE APPROXIMATION; PHOTONS; PHOTOPRODUCTION; PIONS; POLARIZATION; RESCATTERING; SPIN

Citation Formats

Darwish, Eed M., E-mail: eeddarwish@gmail.com, Physics Department, Faculty of Science, Taibah University, Al-Madinah Al-Munawarah, P.O. Box 30002, and Al-Thoyaib, Suleiman S. Coherent π{sup 0}-photoproduction on the deuteron near the η-production threshold including polarization observables. United States: N. p., 2014. Web. doi:10.1016/J.AOP.2014.08.008.
Darwish, Eed M., E-mail: eeddarwish@gmail.com, Physics Department, Faculty of Science, Taibah University, Al-Madinah Al-Munawarah, P.O. Box 30002, & Al-Thoyaib, Suleiman S. Coherent π{sup 0}-photoproduction on the deuteron near the η-production threshold including polarization observables. United States. https://doi.org/10.1016/J.AOP.2014.08.008
Darwish, Eed M., E-mail: eeddarwish@gmail.com, Physics Department, Faculty of Science, Taibah University, Al-Madinah Al-Munawarah, P.O. Box 30002, and Al-Thoyaib, Suleiman S. 2014. "Coherent π{sup 0}-photoproduction on the deuteron near the η-production threshold including polarization observables". United States. https://doi.org/10.1016/J.AOP.2014.08.008.
@article{osti_22403459,
title = {Coherent π{sup 0}-photoproduction on the deuteron near the η-production threshold including polarization observables},
author = {Darwish, Eed M., E-mail: eeddarwish@gmail.com and Physics Department, Faculty of Science, Taibah University, Al-Madinah Al-Munawarah, P.O. Box 30002 and Al-Thoyaib, Suleiman S.},
abstractNote = {Coherent π{sup 0}-photoproduction on the deuteron including polarization observables is studied in the energy region near the η-production threshold at backward center-of-mass angles of the outgoing pion. This work is motivated by the measurements of the CLAS Collaboration at Jefferson Lab, where a cusp-like structure in the energy dependence of the differential cross section has been observed at extremely backward pion angles. The present approach is based on the impulse approximation and first-order rescattering diagrams with intermediate production of both π- and η-mesons. Numerical results for unpolarized cross sections, the linear photon asymmetry (Σ), the vector (T{sub 11}) and tensor (T{sub 2M}, M=0, 1, 2) deuteron target asymmetries, and the double polarization E-asymmetry are predicted and compared with available experimental data and other theoretical models. The effect of first-order rescattering is found to be much larger in spin asymmetries than in the unpolarized cross sections. It reaches on average about 40% in the tensor target and E asymmetries. Compared to the experimental data from CLAS Collaboration, sizable discrepancies are found. This is not the case for the linear photon asymmetry, for which a better comparison with the data from YerPhI Collaboration is obtained.},
doi = {10.1016/J.AOP.2014.08.008},
url = {https://www.osti.gov/biblio/22403459}, journal = {Annals of Physics (New York)},
issn = {0003-4916},
number = ,
volume = 351,
place = {United States},
year = {Mon Dec 15 00:00:00 EST 2014},
month = {Mon Dec 15 00:00:00 EST 2014}
}