Insight into the Narrow Structure in η Photoproduction on the Neutron from Helicity-Dependent Cross Sections (CROSBI ID 232538)
Prilog u časopisu | izvorni znanstveni rad | međunarodna recenzija
Podaci o odgovornosti
Witthauer, M. ; Dieterle, M. ; Achenbach, S. A. ; Afzal, F. ; Ahmed, Z. ; Annand, J. R. M. ; Arends, H. J. ; Bashkanov, M. ; Beck, R. ; Biroth, M. ; Borisov, N. S. ; Braghieri, A. ; Briscoe, W. J. ; Cividini, F. ; Costanza, S. ; Collicott, C. ; Denig, A. ; Downie, E. J. ; Drexler, P. ; Ferretti-Bondy, M. I. ; Gardner, S. ; Garni, S. ; Glazier, D. I. ; Glowa, D. ; Gradl, W. ; Gunther, M. ; Gurevich, G. M. ; Hamilton, D. ; Hornidge, D. ; Huber, G. M. ; Kaser, A. ; Kashevarov, V. L. ; Kay, S. ; Keshelashvili, I. ; Kondratiev, R. ; Korolija, Milorad ; Krusche, B. ; Lazarev, A. B. ; Linturi, J. M. ; Lisin, V. ; Livingston, K. ; Lutterer, S. ; MacGregor, I. J. D. ; Mancell, J. ; Manley, D. M. ; Martel, P. P. ; Metag, V. ; Meyer, W. ; Miskimen, R. ; Mornacchi, E. ; Mushkarenkov, A. ; Neganov, A. B. ; Neiser, A. ; Oberle, M. ; Ostrick, M. ; Otte, P. B. ; Paudyal, D. ; Pedroni, P. ; Polonski, A. ; Prakhov, S. N. ; Rajabi, A. ; Reicherz, G. ; Sokhoyan, V. ; Spieker, K. ; Steffen, O. ; Strakovski, I. I. ; Strub, Th. ; Supek, Ivan ; Thiel, A. ; Thiel, M. ; Thomas, A. ; Unverzagt, M. ; Usov, Yu. A. ; Wagner, S. ; Walford, N. K. ; Watts, D. P. ; Werthmuller, D. ; Wettig, J. ; Wolfes, M. ; Zana, L.
A2 Collaboration at MAMI
engleski
Insight into the Narrow Structure in η Photoproduction on the Neutron from Helicity-Dependent Cross Sections
The double polarization observable E and the helicity dependent cross sections σ1=2 and σ3=2 were measured for η photoproduction from quasifree protons and neutrons. The circularly polarized tagged photon beam of the A2 experiment at the Mainz MAMI accelerator was used in combination with a longitudinally polarized deuterated butanol target. The almost 4π detector setup of the Crystal Ball and TAPS is ideally suited to detect the recoil nucleons and the decay photons from η → 2γ and η → 3π0. The results show that the narrow structure previously observed in η photoproduction from the neutron is only apparent in σ1=2 and hence, most likely related to a spin-1=2 amplitude. Nucleon resonances that contribute to this partial wave in η production are only N1=2− (S11) and N 1=2þ (P11). Furthermore, the extracted Legendre coefficients of the angular distributions for σ1=2 are in good agreement with recent reaction model predictions assuming a narrow resonance in the P11 wave as the origin of this structure.
η photoproduction ; neutron ; helicity-dependent cross sections
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Podaci o izdanju
117 (13)
2016.
132502
5
objavljeno
0031-9007
1079-7114
10.1103/PhysRevLett.117.132502
