Speaker
Description
This work focuses on exploring the Pygmy Dipole Resonance (PDR) in the deformed $^{154}$Sm nucleus. The study employs the ($\vec{\gamma}$,$\vec{\gamma}^{\prime}$) reaction to probe dipole states in the energy range of 3.5$~$MeV to 7.05$~$MeV, approaching the neutron separation energy at 8$~$MeV. Measurements were conducted at the HI$\gamma$S facility of the Triangle Universities Nuclear Laboratory using the Clover Array. The facility provides a polarised photon beam, which enables measurements via the asymmetry method, allowing for the differentiation between $1^{-}$ and $1^{+}$ states. Additionally, the high-resolution beam mode (with an energy spread below 2%) allows for the determination of decay branching ratios to the first $2^{+}$ state, thereby enabling the identification of the $K$ quantum number for the excited states. Since the Alaga rules have so far been investigated in the PDR region only for $^{150}$Nd, the present study aims to extend this investigation to the case of $^{154}$Sm. We present preliminary results and outline prospects for future analysis.
This work is based on the research supported in part by the National Research Foundation of South Africa (Grants No. MND210503598725, No. REP_SARC180529336567) and the US Department of Energy (Grants No. DE-FG02-97ER41041 (UNC), No. DE-FG02-97ER41033 (TUNL)).
