We evaluate the β-decay rates within the gross theory of beta decay (GTBD) and compare the results for different values of the axial-vector coupling constant, g A = 0.76, g A = 0.88, g A = 1, g A = 1.13, and g A = 1.26, and also different energy distribution functions like Gaussian, exponential, Lorentzian, and modified Lorentzian ones. We use new sets of parameters as well as updated experimental mass defects and also an improved approximation for the Fermi function. We compare our calculated results for a set of 94 nuclei of interest in pre-supernova phase, with experimental data in terrestrial conditions and also with other theoretical models like the QRPA, the shell model (SM), and different versions of the GTBD. We show that best results are obtained with g A = 1 using Gaussian and Lorentzian distributions, being the rates for the 74 and 80% of our sample, respectively, of the same order of magnitude that of experimental data. Finally, we show that the present results within the GTBD are better than those within the QRPA model and also older versions of the GTBD for the isotopes of cobalt and iron families, and comparable with SM for some elements.

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We improve the results for the β −-decay rates obtained within the context of the Gross Theory of Beta Decay (GTBD) by using new values of the parameter σ N related to the standard deviation for the Gamow-Teller resonance: we include experimental data when they are available and, if not, we adopt the value of the nearest neighbor previous (that is, with less mass) that has experimental data. We evaluate the β −-decay rates using a Gaussian energy distribution function with the axial-vector weak coupling constant |g A | = 1, considering updated experimental mass defects and also an improved approximation for the Fermi function. Our sample consists of 94 nuclei with mass in the range 46 < A < 70, all of them decaying by means of allowed transitions, which are of interest in the pre-supernova phase and have experimental data in terrestrial conditions available in the Letter of Nuclides. We compare our result with those obtained within the same GTBD but using values of σ N adjusted in Possidonio (Braz. J. Phys. 48:485, 2018) by minimizing the χ 2-function, and also with systematic microscopic calculations. We have shown that the substitution of the adjusted parameters by experimental data in GTBD improves the results for β −-decay rates by 6.4%.