Pygmy resonance and low-energy enhancement in the \(\gamma\)-ray strength functions of Pd~isotopes

An unexpected enhancement in the \(\gamma\)-ray strength function, as compared to the low energy tail of the Giant Dipole Resonance (GDR), has been observed for Sc, Ti, V, Fe and Mo isotopes for \(E_\gamma4\( MeV, which is interpreted as a PDR centered at \)E_{\gamma}\approx8\( MeV. An enhanced \)\gamma\(-ray strength at low energies is also observed for \)^{105}$Pd, which is the lightest isotope measured in this work. Further, the results correspond and agree very well with the observations from the Cd isotopes, and support the suggested transitional region for the onset of low-energy enhancement with decreasing mass number. The neutron number dependency of the PDR strength is also evident.