Alpha Decay in the Complex Energy Shell Model

Abstract

Background: Alpha emission from a nucleus is a fundamental decay process in which the alpha particle formed inside the nucleus tunnels out through the potential barrier.Purpose: We describe alpha decay of 212 Po and 104 Te by means of the configuration interaction approach.Method: To compute the preformation factor and penetrability, we use the complex-energy shell model with a separable T =1 interaction. The single-particle space is expanded in a Woods-Saxon basis that consists of bound and unbound resonant states. Special attention is paid to the treatment of the norm kernel appearing in the definition of the formation amplitude that guarantees the normalization of the channel function.Results: Without explicitly considering the alpha-cluster component in the wave function of the parent nucleus, we reproduce the experimental alpha-decay width of 212 Po and predict an upper limit of T 1/2 = 5.5 × 10 −7 sec for the half-life of 104 Te. Conclusions:The complex-energy shell model in a large valence configuration space is capable of providing a microscopic description of the alpha decay of heavy nuclei having two valence protons and two valence neutrons outside the doubly magic core. The inclusion of proton-neutron interaction between the valence nucleons is likely to shorten the predicted half-live of 104 Te.

$\alpha$α clustering slightly above 100Sn in the light of the new experimental data on the superallowed $\alpha$α decay

“…( 13), the root-mean square (RMS) charge radius of the α particle is found to be [26] r ch = r 2 p + 0.76 − 0.11(N/Z) = 1.67 fm. (15) On the right-hand side of Eq. ( 15), the first term r 2 p = dr r 2 ρ α (r)/ drρ α (r) is the point radius of the α particle, the second term 0.76 fm 2 corresponds to the charge radius squared of the proton, and the third term −0.11 fm 2 corresponds to the charge radius squared of the neutron.…”

“…Other theoretical analyses could be found in, e.g., Ref. [14][15][16]. Recently, a new α-decay chain 108 Xe → 104 Te → 100 Sn is observed experimentally by K. Auranen [17].…”