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arXiv · 1904.12560

Measurement of the Helicity Asymmetry $E$ for the reaction $ γp\to π^0 p$

TAPS collaboration·M. Gottschall·F. Afzal·A. V. Anisovich·D. Bayadilov·R. Beck·M. Bichow·K. -Th. Brinkmann·V. Crede·M. Dieterle·F. Dietz·H. Dutz·H. Eberhardt·D. Elsner·R. Ewald·K. Fornet-Ponse·St. Friedrich·F. Frommberger·A. Gridnev·M. Grüner·E. Gutz·Ch. Hammann·J. Hannappel·J. Hartmann·W. Hillert·Ph. Hoffmeister·Ch. Honisch·T. Jude·S. Kammer·H. Kalinowsky·I. Keshelashvili·P. Klassen·F. Klein·E. Klempt·K. Koop·B. Krusche·M. Kube·M. Lang·I. Lopatin·P. Mahlberg·K. Makonyi·V. Metag·W. Meyer·J. Müller·J. Müllers·M. Nanova·V. Nikonov·R. Novotny·D. Piontek·G. Reicherz·T. Rostomyan·A. Sarantsev·Ch. Schmidt·H. Schmieden·T. Seifen·V. Sokhoyan·K. Spieker·A. Thiel·U. Thoma·M. Urban·H. van Pee·D. Walther·Ch. Wendel·D. Werthmüller·U. Wiedner·A. Wilson·A. Winnebeck·L. Witthauer·Y. Wunderlich
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Abstract

A measurement of the double-polarization observable $E$ for the reaction $γp\to π^0 p$ is reported. The data were taken with the CBELSA/TAPS experiment at the ELSA facility in Bonn using the Bonn frozen-spin butanol (C$_4$H$_9$OH) target, which provided longitudinally-polarized protons. Circularly-polarized photons were produced via bremsstrahlung of longitudinally-polarized electrons. The data cover the photon energy range from $E_γ=600$~MeV to $E_γ=2310$~MeV and nearly the complete angular range. The results are compared to and have been included in recent partial wave analyses.

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TAPS collaboration, M. Gottschall, F. Afzal, A. V. Anisovich, D. Bayadilov, R. Beck, M. Bichow, K. -Th. Brinkmann, V. Crede, M. Dieterle, F. Dietz, H. Dutz, H. Eberhardt, D. Elsner, R. Ewald, K. Fornet-Ponse, St. Friedrich, F. Frommberger, A. Gridnev, M. Grüner, E. Gutz, Ch. Hammann, J. Hannappel, J. Hartmann, W. Hillert, Ph. Hoffmeister, Ch. Honisch, T. Jude, S. Kammer, H. Kalinowsky, I. Keshelashvili, P. Klassen, F. Klein, E. Klempt, K. Koop, B. Krusche, M. Kube, M. Lang, I. Lopatin, P. Mahlberg, K. Makonyi, V. Metag, W. Meyer, J. Müller, J. Müllers, M. Nanova, V. Nikonov, R. Novotny, D. Piontek, G. Reicherz, T. Rostomyan, A. Sarantsev, Ch. Schmidt, H. Schmieden, T. Seifen, V. Sokhoyan, K. Spieker, A. Thiel, U. Thoma, M. Urban, H. van Pee, D. Walther, Ch. Wendel, D. Werthmüller, U. Wiedner, A. Wilson, A. Winnebeck, L. Witthauer, Y. Wunderlich. 2019-04-29. Measurement of the Helicity Asymmetry $E$ for the reaction $ γp\to π^0 p$. https://arxiv.org/abs/1904.12560

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