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arXiv · 1309.7897

Measurement of the $^{1}H$($\vecγ$, $\vec{p}$)$π^{0}$ reaction using a novel nucleon spin polarimeter

D. P. Watts·D. I. Glazier·P. Aguar-Bartolomé·L. K. Akasoy·J. R. M. Annand·H. J. Arends·K. Bantawa·R. Beck·V. S. Bekrenev·H. Berghäuser·A. Braghieri·D. Branford·W. J. Briscoe·J. Brudvik·S. Cherepnya·R. F. B. Codling·B. T. Demissie·E. J. Downie·P. Drexler·L. V. Fil'kov·B. Freehart·R. Gregor·D. Hamilton·E. Heid·D. Hornidge·I. Jaegle·O. Jahn·T. C. Jude·V. L. Kashevarov·I. Keshelashvili·R. Kondratiev·M. Korolija·M. Kotulla·A. A. Koulbardis·S. P. Kruglov·B. Krusche·V. Lisin·K. Livingston·I. J. D. MacGregor·Y. Maghrbi·D. M. Manley·Z. Marinides·M. Martinez·J. C. McGeorge·B. McKinnon·E. F. McNicoll·D. Mekterovic·V. Metag·S. Micanovic·D. G. Middleton·A. Mushkarenkov·B. M. K. Nefkens·A. Nikolaev·R. Novotny·M. Ostrick·P. B. Otte·B. Oussena·P. Pedroni·F. Pheron·A. Polonski·S. Prakhov·J. Robinson·G. Rosner·T. Rostomyan·S. Schumann·D. I. Sober·A. Starostin·I. I. Strakovsky·I. M. Suarez·I. Supek·M. Thiel·A. Thomas·M. Unverzagt·D. Werthmüller·R. L. Workman·I. Zamboni·F. Zehr
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Abstract

We report the first large-acceptance measurement of polarization transfer from a polarized photon beam to a recoiling nucleon, pioneering a novel polarimetry technique with wide application to future nuclear and hadronic physics experiments. The commissioning measurement of polarization transfer in the $^{1}H$($\vecγ$,$\vec{p}$)$π^{0}$ reaction in the range $0.4<E_γ<1.4$ GeV is highly selective regarding the basic parameterizations used in partial wave analyses to extract the nucleon excitation spectrum. The new data strongly favor the recently proposed Chew-Mandelstam formalism.

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D. P. Watts, D. I. Glazier, P. Aguar-Bartolomé, L. K. Akasoy, J. R. M. Annand, H. J. Arends, K. Bantawa, R. Beck, V. S. Bekrenev, H. Berghäuser, A. Braghieri, D. Branford, W. J. Briscoe, J. Brudvik, S. Cherepnya, R. F. B. Codling, B. T. Demissie, E. J. Downie, P. Drexler, L. V. Fil'kov, B. Freehart, R. Gregor, D. Hamilton, E. Heid, D. Hornidge, I. Jaegle, O. Jahn, T. C. Jude, V. L. Kashevarov, I. Keshelashvili, R. Kondratiev, M. Korolija, M. Kotulla, A. A. Koulbardis, S. P. Kruglov, B. Krusche, V. Lisin, K. Livingston, I. J. D. MacGregor, Y. Maghrbi, D. M. Manley, Z. Marinides, M. Martinez, J. C. McGeorge, B. McKinnon, E. F. McNicoll, D. Mekterovic, V. Metag, S. Micanovic, D. G. Middleton, A. Mushkarenkov, B. M. K. Nefkens, A. Nikolaev, R. Novotny, M. Ostrick, P. B. Otte, B. Oussena, P. Pedroni, F. Pheron, A. Polonski, S. Prakhov, J. Robinson, G. Rosner, T. Rostomyan, S. Schumann, D. I. Sober, A. Starostin, I. I. Strakovsky, I. M. Suarez, I. Supek, M. Thiel, A. Thomas, M. Unverzagt, D. Werthmüller, R. L. Workman, I. Zamboni, F. Zehr. 2013-09-30. Measurement of the $^{1}H$($\vecγ$, $\vec{p}$)$π^{0}$ reaction using a novel nucleon spin polarimeter. https://doi.org/10.1103/physrevlett.112.022501

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