Journal article

Publication year: 1997

Pages: 1509-1516

Journal: Physical Review C

Volume number: 55

Issue number: 3

ISSN: 0556-2813

eISSN: 1089-490X

Open access status: Green

DOI Link: https://doi.org/10.1103/PhysRevC.55.1509

Publisher: American Physical Society

Abstract: 
A rigorous multipole analysis of the recent gamma p-->pi(0)p cross-section measurement is presented. The data were taken using the photon spectrometer TAPS at the tagged photon beam of the Mainz microtron. The s and p wave multipoles were extracted using minimal model assumptions. The predicted unitary cusp for the s-wave multipole E(0+) due to the two step gamma p-->pi(+)n-->pi(0)p reaction was observed. The results are consistent with one-loop chiral perturbation theory calculations for which three low-energy constants have been determined by a fit to the data. The uncertainties in the analysis and the need for polarization observables are discussed.

Harvard Citation style: Bernstein, A., Shuster, E., Beck, R., Fuchs, M., Krusche, B., Merkel, H., et al. (1997) Observation of a unitary cusp in the threshold gamma p->pi(0)p reaction, Physical Review C, 55(3), pp. 1509-1516. https://doi.org/10.1103/PhysRevC.55.1509

APA Citation style: Bernstein, A., Shuster, E., Beck, R., Fuchs, M., Krusche, B., Merkel, H., & Stroher, H. (1997). Observation of a unitary cusp in the threshold gamma p->pi(0)p reaction. Physical Review C. 55(3), 1509-1516. https://doi.org/10.1103/PhysRevC.55.1509