Search for deeply bound pionic states in208Pb via radiative atomic capture of negative pions

Autor: K.S. Sim, S. Yen, D.F. Ottewell, A. Olin, J.B. Lange, A. Trudel, S.J. Lee, E. Friedman, K. Raywood, A. Altman, M. Pavan, M. E. Sevior, G. A. C. Jones, D. A. Hutcheon
Rok vydání: 1997
Předmět:
Zdroj: Physical Review C. 55:2492-2500
ISSN: 1089-490X
0556-2813
DOI: 10.1103/physrevc.55.2492
Popis: A search for narrow, deeply bound pionic atom states via atomic radiative capture of negative pions in a target of {sup 208}Pb was carried out for pion kinetic energies of 20 and 25 MeV. Although no clear signature of any such gamma ray emission could be observed in the data, fits of the gamma ray spectra between the energies of 12 and 42 MeV involving a quadratic background together with a pair of peaks (1s, 2p) whose relative intensity was taken from theory yielded an overall strength for the peaks which are consistent (to a 67{percent} confidence level) with radiative capture whose integrated cross section is 20.0 {plus_minus} 10.0 {mu}b/sr at 90{degree} for 20 MeV incident pions. A lower probability (40{percent} confidence level) result was obtained when the fit was carried out without the peaks included, just the continuum background. {copyright} {ital 1997} {ital The American Physical Society}
Databáze: OpenAIRE
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