Anomalous angular distributions in pion and α particle scattering to the22+state ofCr52
| Autor: | R. J. Peterson, H. T. Fortune, D. S. Oakley, C. L. Morris |
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| Rok vydání: | 1996 |
| Předmět: | |
| Zdroj: | Physical Review C. 53:689-694 |
| ISSN: | 1089-490X 0556-2813 |
| Popis: | Inelastic scattering of 180 MeV {pi}{sup +} and {pi}{sup {minus}} from {sup 52}Cr shows an angular distribution for the 2{sub 2}{sup +} state at 2.96 MeV that differs greatly from the usual {ital L} = 2 shapes for 2{sup +} states. This state is perhaps the only case from pion-inelastic scattering in which standard distorted-wave impulse approximation models (including multistep and single-step responses) fail to reproduce the measured angular distribution. Furthermore, this unique excitation has been shown to have the features expected of a seniority-four proton excitation yet the pion data show charge symmetry. While coupled-channel calculations are not able to reproduce the pion data, they do agree with the shape observed for 42 MeV {alpha} particle scattering to this state, but the magnitude of the {alpha} scattering data is not consistent with a collective model and known {gamma} ray deexcitations. Scattering to the first and third 2{sup +} states of {sup 52}Cr with pions and {alpha} particles is also considered, and found to match the usual result for 2{sup +} states in general, accentuating the anomaly of this 2{sub 2}{sup +} transition. {copyright} {ital 1996 The American Physical Society.} |
| Databáze: | OpenAIRE |
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