RT Journal Article
T1 Unitarity and gamma-gamma-]pi-pi in chiral perturbation-theory
A1 Dobado González, Antonio
A1 Peláez Sagredo, José Ramón
AB The direct chiral perturbation theory (ChPT) one-loop prediction for the production of two pions from two photons is compared with the recent Crystal Ball experimental data. The one-loop computation does not fit data even close to threshold because unitarity effects are important even at very low energies. However, when the constraints coming from unitarity and analyticity are included in a suitable way, the range of application of one-loop ChPT can be largely extended in agreement with the experiment.
PB Springer Verlag
SN 0170-9739
YR 1993
FD 1993-02
LK https://hdl.handle.net/20.500.14352/58751
UL https://hdl.handle.net/20.500.14352/58751
DS Docta Complutense
RD 15 dic 2025