📝 SummarXiv

Abstract

Reliable nuclear weak rates are key inputs for understanding the origin of heavy elements and constraining the environments of the corresponding stellar nucleosynthesis. We present the effective stellar $\beta^-$-decay rates of the $N=50, 82, 126$ $r$-process waiting-point nuclei in realistic stellar environments with high temperature, high density and strong magnetic field. Both allowed and first-forbidden transitions are considered, and transitions from the low-lying states of parent nuclei due to the thermal population are taken into account properly. The stellar $\beta^-$-decay rates of the $N=50, 82$ waiting points are not sensitive to stellar temperature, while those of the $N=126$ waiting points increase rapidly with stellar temperature. With the increase of stellar density, the electron chemical potential increases accordingly, which leads to reduction of the stellar $\beta$-decay rates. Besides, the stellar $\beta$-decay rates are found to increase rapidly with the magnetic field $B$ when $B \gtrsim 10^{14}$ G. Depending on the stellar temperature, density and magnetic field, the rates may vary by several orders of magnitude, which indicates that dynamic $\beta$-decay rates for corresponding stellar conditions may be indispensable inputs for understanding the $r$-process nucleosynthesis.