Izvorni znanstveni članak
Spin observables in pion photoproduction from a unitary and causal effective field theory
A. M. Gasparyan
; GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstrasse 1, 64291 Darmstadt, Germany
M. F. M. Lutz
; SSC RF ITEP, Bolshaya Cheremushkinskaya 25, 117218 Moscow, Russia
Sažetak
Pion photoproduction is analyzed with the chiral Lagrangian. Partial-wave amplitudes are obtained by an analytic extrapolation of sub-threshold reaction amplitudes computed in chiral perturbation theory, where the constraints set by electromagnetic-gauge invariance, causality and unitarity are used to stabilize the extrapolation. The experimental data set is reproduced up to energies √ s ≃ 1300 MeV in terms of the parameters relevant at order Q3 . We present and discuss predictions for various spin observables.
Ključne riječi
pion photoproduction; chiral perturbation theory; stabilization of extrapolation; spin observables
Hrčak ID:
304630
URI
Datum izdavanja:
1.3.2011.
Posjeta: 116 *