Allowed and unique first-forbidden stellar electron emission rates of neutron-rich copper isotopes

Ground-state Nuclear Properties of Neutron-rich Copper Isotopes and Lepton Capture Rates in Stellar Matter

“…The same FF contribution to total β-decay half-lives was also studied by [21] using the large scale shell model approach. Recently, the deformed pn-QRPA model was used for the calculation of both GT and U1F (having |∆J| = 2) transitions of 72−82 Cu nuclide in stellar scenario [22]. There the authors concluded that, for 80−82 Cu, a substantial part of the total β − -decay rates came from U1F strength, in line with the conclusion of Borzov [23].…”

“…We will assume that the positrons follow the same energy distribution as the electrons. We later consider the capturing of these positrons in our calculation (a process that competes with the β-decay rates presented earlier in [22]). We further assume in our calculation that, for the range of stellar density considered in this work, the neutrinos and antineutrinos (produced due to lepton capture reactions) escape freely from the stellar core (neutrino capture is not considered in our calculation).…”

“…[38]. Earlier, the stellar electron emission rates for the selected Cu isotopes were computed [22] using deformation from Ref. [38].…”

“…The strength of U1F to total β − -decay rates decreases, when stellar density increases. However, the lepton capture rates contribution (both allowed GT and U1F) were not calculated in [22]. The PC rates may compete with the electron emission rates under stellar conditions.…”

“…The PC rates may compete with the electron emission rates under stellar conditions. Further, the relative contribution of capture rates to the total stellar weak rates was also missing in [22]. In the later portion of this study, we compute EC and PC rates for neutron-rich copper isotopes (71 ≤ A ≤ 82) employing the deformed pn-QRPA model in stellar environment.…”