Geant4 Simulations for the Radon Electric Dipole Moment Search at

Figure 1.3: Illustration of the double well potential as a function of β 3 that arises
for octupole-deformed nuclei. The magnitude of octupole (L = 3) deformation is described
by the parameter β 3 , where β 3 measures the presence ofthe octupole spherical
harmonic in the nuclear shape.
potential with one potential well for the N atom on either side of the H 3 plane. The
wave function for the N atom can be either symmetric or anti-symmetric with the
two states of opposite parity representing equal admixtures of the intrinsic states
populated by tunnelling through the H 3 plane and split by a small energy difference
∆E associated with the tunnelling process. The same physics applies to octupole
deformed nuclei in which a doublet of states with opposite parity and a small energy
splitting ∆E results from equal admixtures of the two intrinsic states at ±β, and the
tunnelling through a large potential energy barrier at β 3 = 0.
To completely describe the P-, T-odd nuclear potential V PT in Equation 1.6, a
two-body interaction is required. However for the purpose of estimating the collective
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