Influence of the axial-vector coupling constant and the energy distribution function on beta-decay rates within the Gross Theory of Beta Decay

D.N. POSSIDONIO; R.C. FERREIRA; A.J. DIMARCO; C. BARBERO; A.R. SAMANA; M.R. AZEVEDO; C.L. SANTANA; A. MARIANO

BRAZILIAN JOURNAL OF PHYSICS

SOC BRASILEIRA FISICA

Lugar: SAN PABLO; Año: 2018

0103-9733

We evaluate the $eta$-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 differentenergy distribution functions like Gaussian, exponential, Lorentzian and modifiedLorentzian ones. We use new sets of parameters as well as updated experimentalmass defects and we suppress some approaches like those employed in the Fermifunction. We compare our calculated results for a set $94$ cores nuclei of interest inpre-supernova phase, with experimental data in terrestrial conditions and also withother theoretical models like the QRPA, the shell model (SM) and different versions ofthe GTBD.We show that best results are obtained with $g_A=1$ using Gaussian and Lorentziandistributions, being the rates for the $74 %$ and 80% of our sample, respectively, ofthe same order of magnitude that experimental data. Finally, we show that presentresults within the GTBD are better than those within the QRPA model and also olderversions of the GTBD for the isotopes of cobalt and iron families, and comparable withSM for some elements.Suggested Reviewers: Deppman AirtonPowered