Measurement of the beam-helicity asymmetry in photoproduction of π0η pairs on carbon, aluminum, and lead

A2 Collaboration at MAMI, K. Livingston, S. Lutterer, I. J.D. MacGregor, R. Macrae, D. M. Manley, P. P. Martel, J. C. McGeorge, D.G. Middleton, R. Miskimen, E. Mornacchi, C. Mullen, A. Mushkarenkov, A. Neganov, A. Neiser, M. Oberle, M. Ostrick, P. B. Otte, D. Paudyal, P. Pedroni

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The beam-helicity asymmetry was measured, for the first time, in photoproduction of $\pi^{0}\eta$ pairs on carbon, aluminum, and lead, with the A2 experimental setup at MAMI. The results are compared to an earlier measurement on a free proton and to the corresponding theoretical calculations. The Mainz model is used to predict the beam-helicity asymmetry for the nuclear targets. The present results indicate that the photoproduction mechanism for $\pi^{0}\eta$ pairs on nuclei is similar to photoproduction on a free nucleon. This process is dominated by the $D_{33}$ partial wave with the $\eta\Delta(1232)$ intermediate state.
Original languageEnglish
Article number135243
Number of pages8
JournalPhysics Letters B
Early online date23 Jan 2020
Publication statusPublished - 10 Mar 2020

Bibliographical note

© 2020 The Author(s). Published by Elsevier B.V
8 pages, 2 figures. arXiv admin note: text overlap with arXiv:1803.00727


  • nucl-ex

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