Testing the Mutually Enhanced Magicity (MEM) effect in the Giant Monopole Resonance (GMR) in the $^{204-208}$Pb isotopes
ORAL
Abstract
Recent study of the giant monopole resonance (GMR) in the even A, $^{112-124}$Sn[1] and $^{106-116}$Cd isotopes showed discrepancy in the centroid energy of GMR peak when compared with the theoretical calculations. It has been suggested [2] that this discrepancy might result from the MEM effect [3]. A consequence of this hypothesis would be significantly high GMR energy in the doubly-magic $^{208}$Pb nucleus when compared with the nearby Pb isotopes. We have investigated GMR in $^{204-208}$Pb isotopes in an experiment performed at RCNP, Osaka University, Japan. Measurements were taken at forward angles, including 0\r{ }, using a 400 MeV $\alpha $ beam. Preliminary results indicate that this hypothesis does not hold.
*Ref: [1] T. Li et al., Phys. Rev. Lett. 99, 162503 (2007) [2] E. Khan, Phys. Rev. C 80, 011307, 057302 (2009) [3] N. Zeldes et al., Nucl. Phys. A399, 11 (1983)
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