https://doi.org/10.1140/epja/i2011-11143-y
Regular Article - Theoretical Physics
Model dependence of single-energy fits to pion photoproduction data
1
Center for Nuclear Studies, Department of Physics, The George Washington University, Washington, D.C., 20052, USA
2
Institut für Kernphysik, Johannes Gutenberg Universität, D-55099, Mainz, Germany
3
Bogoliubov Laboratory for Theoretical Physics, JINR Dubna, 141980, Moscow Region, Russia
* e-mail: tiator@kph.uni-mainz.de
Received:
30
May
2011
Revised:
7
October
2011
Accepted:
3
November
2011
Published online:
25
November
2011
Model dependence of multipole analysis has been explored through energy-dependent and single-energy fits to pion photoproduction data. The MAID energy-dependent solution has been used as input for an event generator producing realistic pseudo data. These were fitted using the SAID parametrization approach to determine single-energy and energy-dependent solutions over a range of lab photon energies from 200 to 1200MeV. The resulting solutions were found to be consistent with the input amplitudes from MAID. Fits with a χ-squared per datum of unity or less were generally achieved. We discuss energy regions where consistent results are expected, and explore the sensitivity of fits to the number of included single- and double-polarization observables. The influence of Watson’s theorem is examined in detail.
© SIF, Springer-Verlag Berlin Heidelberg, 2011
