New Coulomb Excitation Measurement of $^{18}$Ne

Reduced transition probability $B({\rm E2};0^{+}_{\rm g.s.} \rightarrow 2^{+}_{1})$ of $^{18}$Ne has been measured by the intermediate-energy Coulomb excitation. The previous work on Coulomb excitation measurement$^{1)}$ reported a $B({\rm E2})$ value that remarkably disagreed with two lifetime measurements$^{2,3)}$. The present study is aimed at providing a new Coulomb excitation data with a precise angular distribution to clarify if the discrepancy is accidental or due to the reaction mechanism. A secondary $^{18}$Ne beam at 54~$A$MeV produced by RIPS in RIKEN irradiated a lead target. De-excitation $\gamma$-rays were measured by an array of 68 NaI (Tl) detectors surrounding the lead target in coincidence with the incident beam and scattered particles. The $B({\rm E2})$ value was extracted with the help of DWBA analysis, where the nuclear excitation component was constrained from $B({\rm E2})$ of $^{18}$O, the mirror of $^{18}$Ne, assuming the isospin symmetry. \\ {\bf References}\\ 1) L.A.~Riley et al., Phys. Rev. C {\bf 62}, 034306 (2000).\\ 2) A.B.~McDonald et al., Nucl. Phys. {\bf A258}, 152 (1976).\\ 3) L.A.~Riley et al., Phys. Rev. C {\bf 68}, 044309 (2003).\\