Enhancement of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>α</mml:mi></mml:math>-particle formation near <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mmultiscripts><mml:mi>Sn</mml:mi><mml:mprescripts/><mml:none/><mml:mn>100</mml:mn></mml:mmultiscripts></mml:math>
R. M. Clark, A. O. Macchiavelli, H. L. Crawford, P. Fallon, D. Rudolph, A. Såmark-Roth, C. M. Campbell, M. Cromaz, C. Morse, C. Santamaria
Abstract
The superfluid tunneling model is applied to the calculation of ground-state--to--ground-state \ensuremath{\alpha} decay in the even-even neutron-deficient Te-Ba nuclei. We show that there is a larger \ensuremath{\alpha}-particle formation probability in nuclei of this region above $^{100}\mathrm{Sn}$ when compared to analogous nuclei above $^{208}\mathrm{Pb}$. This is consistent with the expected systematic variation of the pair gap $\mathrm{\ensuremath{\Delta}}$ as a function of mass number. The recent experimental data on the \ensuremath{\alpha} decay of the $N=Z$ nuclei $^{104}\mathrm{Te}$ and $^{108}\mathrm{Xe}$ are shown to leave open the possibility of enhanced \ensuremath{\alpha}-particle formation involving nucleon correlations beyond the standard treatment of like-nucleon pairing, which is the mechanism suggested as underlying ``superallowed'' \ensuremath{\alpha} decay.