Systematics on the low-lying spectra in N = 78 ~ 80 isotones

Abstract

Combining the new spectroscopy results of 144 Tb and previous spectroscopy studies of neighboring nuclei, a systematic investigation on the low-lying spectra in N = 78 ∼ 80 isotones is performed. Good systematics have been found for the coupling patterns which couple the odd nucleon(s), such as πh 11/2 , νh −1 11/2 , πh 2 11/2 , νh −2 11/2 , πh 11/2 νh −1 11/2 , to the 2 + , 4 + , 6 + and 3 − core excitations. It is found that the relative excitation energies of the states formed by coupling h 11/2 proton(s) to the 2 + , 4 + core excitations are pushed up, in contrast with those formed by coupling h 11/2 neutron hole(s) to the 2 + , 4 + core excitations, which are pulled down. According to the systematics, the interpretation that the 17/2 + states observed in 141 Sm and 143 Gd are the fully aligned member of coupling the odd h 11/2 neutron hole to the octupole 3 − core excitation, is explored to the isotones 145 Dy, 142 Eu, and 144 Tb.

Gate-tunable third-order nonlinear optical response of massless Dirac fermions in graphene

“…It is now possible to well predict the dependence of the third-order nonlinear responses of graphene on input frequencies and doping level. The understanding can be extended to other nonlinear optical processes in graphene, such as effective second-order processes [40][41][42] , and even high-order harmonic generation 25 .…”