https://doi.org/10.1140/epja/i2008-10743-x
Regular Article - Theoretical Physics
Backward pion photoproduction
1
Helmholtz-Institut für Strahlen- und Kernphysik and Bethe Center for Theoretical Physics, Universität Bonn, D-53115, Bonn, Germany
2
Excited Baryon Analysis Center (EBAC), Thomas Jefferson National Accelerator Facility, 23606, Newport News, VA, USA
3
Institut für Kernphysik and Jülich Centre for Hadron Physics, Forschungszentrum Jülich, D-52425, Jülich, Germany
4
Institute for Advanced Simulations, Forschungszentrum Jülich, D-52425, Jülich, Germany
* e-mail: s.krewald@fz-juelich.de
Received:
27
November
2008
Accepted:
3
March
2009
Published online:
31
March
2009
We present a systematic analysis of backward pion photoproduction for the reactions 
p
p and
p
n . Regge phenomenology is applied at invariant collision energies above 3GeV in order to fix the reaction amplitude. A comparision with older data on - and -photoproduction at 
= 180° indicates that the high-energy limit as given by the Regge calculation could be reached possibly at energies of around 
≃ 3 GeV. In the energy region of
2.5 GeV, covered by the new measurements of
p
p differential cross-sections at large angles at ELSA, JLab, and LEPS, we see no clear signal for a convergence towards the Regge results. The baryon trajectories obtained in our analysis are in good agreement with those given by the spectrum of excited baryons.
PACS: 11.55.Jy Regge formalism – / 13.60.Le Meson production – / 25.20.Lj Photoproduction reactions –
© SIF, Springer-Verlag Berlin Heidelberg, 2009
