First measurement of the polarization observable E and helicity-dependent cross sections in single π0 photoproduction from quasi-free nucleons
نویسندگان
چکیده
M. Dieterle a, L. Witthauer a, F. Cividini b, S. Abt a, P. Achenbach b, P. Adlarson b, F. Afzal c, Z. Ahmed d, C.S. Akondi e, J.R.M. Annand f, H.J. Arends b, M. Bashkanov g, R. Beck c, M. Biroth b, N.S. Borisov h, A. Braghieri i, W.J. Briscoe j, S. Costanza i,1, C. Collicott k, A. Denig b, E.J. Downie b,j, P. Drexler b, M.I. Ferretti-Bondy b, S. Gardner f, S. Garni a, D.I. Glazier f,g, D. Glowa g, W. Gradl b, M. Günther a, G.M. Gurevich l, D. Hamilton f, D. Hornidgem, G.M. Huber d, A. Käser a, V.L. Kashevarov b, S. Kay g, I. Keshelashvili a,2, R. Kondratiev l, M. Korolija n, B. Krusche a,∗, A.B. Lazarev h, J.M. Linturi b, V. Lisin l, K. Livingston f, S. Lutterer a, I.J.D. MacGregor f, J. Mancell f, D.M. Manley e, P.P. Martel b,m, V. Metag o, W. Meyer p, R. Miskimen q, E. Mornacchi b, A. Mushkarenkov l,q, A.B. Neganov h, A. Neiser b, M. Oberle a, M. Ostrick b, P.B. Otte b, D. Paudyal d, P. Pedroni i, A. Polonski l, S.N. Prakhov b,r, A. Rajabi q, G. Reicherz p, G. Ron s, T. Rostomyan a,3, A. Sarty k, C. Sfienti b, M.H. Sikora g, V. Sokhoyan b,j, K. Spieker c, O. Steffen b, I.I. Strakovsky j, Th. Strub a, I. Supek n, A. Thiel c, M. Thiel b, A. Thomas b, M. Unverzagt b, Yu.A. Usov h, S. Wagner b, N.K. Walford a, D.P. Watts g, D. Werthmüller a,f, J. Wettig b, M. Wolfes b, L. Zana g
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Measurement of the beam-helicity asymmetry I in the photoproduction of π0π± pairs off protons and off neutrons
Beam-helicity asymmetries have been measured at the MAMI accelerator in Mainz for the photoproduction of mixed-charge pion pairs in the reactions γp → nππ off free protons and γd → (p)pπ0π− and γd → (n)nππ off quasi-free nucleons bound in the deuteron for incident photon energies up to 1.4GeV. Circularly polarized photons were produced from bremsstrahlung of longitudinally polarized electrons a...
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