The effect of the pairing interaction on the energies of isobar analogue resonances in^112–124Sb and isospin admixture in^100–124Sn isotopes

Abstract

In the present study, the effect of the pairing interaction and the isovector correlation between nucleons on the properties of the isobar analog resonances (IAR) in 112−124 Sb isotopes and the isospin admixture in 100−124 Sn isotopes is investigated within the framework of the quasiparticle random phase approximation (QRPA). The form of the interaction strength parameter is related to the shell model potential by restoring the isotopic invariance of the nuclear part of the total Hamiltonian. In this respect, the isospin admixtures in the 100−124 Sn isotopes are calculated, and the dependence of the differential cross section and the volume integral J F for the Sn( 3 He,t)Sb reactions at E( 3 He)= 200 MeV occurring by the excitation of IAR on mass number A is examined. Our results show that the calculated value for the isospin mixing in the 100 Sn isotope is in good agreement with Colo et al.'s estimates (4 − 5%), and the obtained values for the volume integral change within the error range of the value reported by Fujiwara et al. (53±5 MeV fm 3 ). Moreover, it is concluded that although the differential cross section of the isobar analog resonance for the ( 3 He,t) reactions is not sensitive to pairing correlations between nucleons, a considerable effect on the isospin admixtures in N ≈ Z isotopes can be seen with the presence of these correlations.

Deformation effects on isospin mixing and isobar analogue resonance for 74−80Kr isotopes

“…Naturally, the calculated results depend on the choice of the mean field parameters and pairing gaps. The sensitivity of isobar analogue states to the mean field parameters and pairing interaction was studied by using Pyatov's method within the pnQRPA formalism [28,33]. In order to understand the deformation effects on the isobar analogue states in 74−80 Rb isotopes, the mean field parameters and pairing gaps are fixed.…”

“…These restorations played an important role in the investigation of the electric dipole excitations (1 − ) and magnetic dipole excitations (1 + ) in even-even nuclei. The same method was used to restore the isospin invariance of the nuclear Hamiltonian and the problem of the isospin mixing in the ground states was studied for the spherical odd-odd nuclei [28][29][30][31]. The method has not been applied for the study of the isobar analogue states in the deformed odd-odd nuclei yet.…”

Superallowed Fermi Beta Decay and the Unitarity of the Cabibbo-Kobayashi-Maskawa Matrix

“…The data for f t, δ R (%), δ NS (%), δ C2 (%), and ∆ v R = (2.361 ∓ 0.038)% are adopted from [45]. The nucleus independent radiative correction ∆ V R is included in the Ft values in (28).…”

“…In [11] has been [44] from [44] given only total δ C (δ C = δ C1 + δ C2 ) however it implies that δ C1 is negative for the 10 Table 2. The Ft values are calculated using (28).…”

Investigation of isospin forbidden 0+ → 0+ Fermi beta decays with Pyatov method

“…Pyatov method was used in several studies [14][15][16][17][18][19][20][21][22][23]. In our previous studies, the Cabbibo-Kobayashi-Maskawa (CKM) matrix unitarity [24,25], the values of superallowed fermi beta decays [26] and isospin admixtures and isospin structure of isobar analog resonance states of superallowed beta decays [27] were investigated without and with pairing interactions, by using this method.…”