Quantum design in study of pycnonuclear reactions in compact stars and new quasibound states

Abstract

Pycnonuclear reactions in the compact stars at zero temperatures are studied on quantum mechanical basis in the paper. Formalism of multiple internal reflections is generalized for analysis, that was developed for nuclear decays and captures by nuclei with high precision and tests. For the chosen reaction $^{12}$C + $^{12}$C = $^{24}$Mg, we find the following. A quantum study of the pycnonuclear reaction requires a complete analysis of quantum fluxes in the internal nuclear region. This reduces rate and number of pycnonuclear reactions by 1.8 times. This leads to the appearance of new states (called as quasibound states) where the compound nuclear system is formed with maximal probability. As shown, minimal energy of such a state is a little higher than energy of zero-point vibrations in lattice sites in pycnonuclear reaction, however probability of formation of compound system at the quasibound state is essentially larger than the corresponding probability at state of zero-point vibrations. Hence, there is a sense to tell about reaction rates in such quasibound states as more probable, rather than states of zero-point vibrations. This can lead to the essential changes in estimation of the rates of nuclear reactions in stars.