@article{c1d1b8902aea401bad97aced0181a265,
title = "Measurement of the π+-meson polarizabilities via the γp → γπ+n reaction",
abstract = "An experiment on the radiative π+-meson photoproduction from the proton (γp → γπ+n) was carried out at the Mainz Microtron MAMI in the kinematic region 537MeV < Eγ < 817MeV, 140° ≤ θγγ′cm ≤ 180°. The π+-meson polarizabilities have been determined from a comparison of the data with the predictions of two different theoretical models, the first one being based on an effective pole model with pseudoscalar coupling while the second one is based on diagrams describing both resonant and nonresonant contributions. The validity of the models has been verified by comparing the predictions with the present experimental data in the kinematic region where the pion polariza,bility contribution is negligible (s1 < 5mπ2) and where the difference between the predictions of the two models does not exceed 3%. In the region, where the pion polarizability contribution is substantial (5 < s1/m π2 < 15, -12 < t/mπ2 < -2), the difference (α - β)π+ of the electric (α) and the magnetic (β) polarizabilities has been determined. As a result we find (α - β)π+ = (11.6 ± 1.5 stat ± 3.0syst ± 0.5mod) × 10-4 fm3. This result is at variance with recent calculations in the framework of chiral perturbation theory.",
author = "J. Ahrens and Alexeev, {V. M.} and Annand, {J. R.M.} and Arends, {H. J.} and R. Beck and G. Caselotti and Cherepnya, {S. N.} and D. Drechsel and Fil'kov, {L. V.} and K. F{\"o}hl and I. Giller and P. Grabmayr and T. Hehl and D. Hornidge and Kashevarov, {V. L.} and M. Kotulla and D. Krambrich and B. Krusche and M. Lang and McGeorge, {J. C.} and MacGregor, {I. J.D.} and V. Metag and M. Moinester and R. Novotny and M. Pfeiffer and M. Rost and S. Schadmand and S. Scherer and A. Thomas and C. Unkmeir and Th Walcher",
note = "Funding Information: We would like to acknowledge the Australian Bureau of Meteorology for providing daily rainfall data (accessed online via http://www.bom.gov.au/jsp/awap/rain/archive_recal.jsp), the support of the European Space Agency SMOS+rainfall project (contract 4000114738/15/I-SBo), and of the Centre National d'Etudes Spatiales TOSCA. SMOS L3SM product was provided by the Centre Aval de Traitement des Donn?es SMOS (CATDS), developed by CNES in collaboration with CESBIO and IFREMER. All the input data sets used in the paper are available for free through public websites. The four rainfall products estimated/corrected by using SMOS soil moisture data are available upon request from the corresponding author.",
year = "2005",
month = jan,
doi = "10.1140/epja/i2004-10056-2",
language = "אנגלית",
volume = "23",
pages = "113--127",
journal = "European Physical Journal A",
issn = "1434-6001",
publisher = "Springer Verlag",
number = "1",
}