Search for Narrow Nucleon Resonances below Pion Threshold in the H(e,e'pi^+)X and D(e,e'p)X Reactions

M. Kohl; M. Ases Antelo; C. Ayerbe; D. Baumann; R. Boehm; D. Bosnar; M. Ding; M. O. Distler; J. Friedrich; J. Garcia Llongo; P. Jennewein; G. Jover Manas; H. Merkel; P. Merle; U. Mueller; R. Neuhausen; L. Nungesser; R. Perez Benito; J. Pochodzalla; M. Potokar; C. Rangacharyulu; A. Richter; G. Schrieder; M. Seimetz; Th. Walcher; M. Weis

doi:10.1103/physrevc.67.065204

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Search for Narrow Nucleon Resonances below Pion Threshold in the H(e,e'pi^+)X and D(e,e'p)X Reactions

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Abstract

In two series of high-resolution coincidence experiments at the three-spectrometer facility at MAMI, the H(e,e'pi^+)X and D(e,e'p)X reactions were studied to search for narrow nucleon resonances below pion threshold. The missing-mass resolution was 0.6 to 1.6 MeV/c^2 (FWHM) in the proton experiment and 0.9 to 1.3 MeV/c^2 in the deuteron experiment. The experiments covered the missing-mass region from the neutron mass up to about 1050 and 1100 MeV/c^2, respectively. None of our measurements showed a signal for narrow resonances to a level of down to 10^-4 with respect to the neutron peak in the missing-mass spectra.

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M. Kohl, M. Ases Antelo, C. Ayerbe, D. Baumann, R. Boehm, D. Bosnar, M. Ding, M. O. Distler, J. Friedrich, J. Garcia Llongo, P. Jennewein, G. Jover Manas, H. Merkel, P. Merle, U. Mueller, R. Neuhausen, L. Nungesser, R. Perez Benito, J. Pochodzalla, M. Potokar, C. Rangacharyulu, A. Richter, G. Schrieder, M. Seimetz, Th. Walcher, M. Weis. 2003-04-11. Search for Narrow Nucleon Resonances below Pion Threshold in the H(e,e'pi^+)X and D(e,e'p)X Reactions. https://doi.org/10.1103/physrevc.67.065204

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