A unified formula for α decay half-lives

Based on the Hatsukawa formula (Hatsukawa et al. in Phys Rev C 42:674, 1990), modifying the coefficient F( Z) and considering the blocking effect of unpaired nucleons, in our previous work (Xu and Liu in Eur Phys J A 58:16, 2022) we proposed an improved semi-empirical formula for evaluating the favored alpha decay half-lives. In this work, considering the contribution of centrifugal potential, we generalize this formula to unfavored alpha decay and propose a unified formula for alpha decay half-lives. Using this formula, we systematically calculate the unfavored a decay half-lives of 130 odd-A and 78 odd-odd nuclei with the corresponding rootmean-square (rms) deviations being 0.503 and 0.603, respectively. Meanwhile the rms deviation of alpha decay half-lives for all the 700 nuclei taken from NUBASE2020 is only 0.380. Moreover, we extend this formula to predict the a decay halflives of 144 even-even, odd-A and odd-odd nuclei with Z = 117, 118, 119 and 120. For comparison, the unitary Royer formula (DZR) (Deng et al. in PhysRevC101:034307, 2020) proposed by Deng et al. and themodified universal decay law (MUDL) (Soylu and Qi in Nucl Phys A 1013:122221, 2021) proposed by Soylu et al. are also used. The predictions of these formulas are basically consistent with each other.