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Abstract

Studying the weak nuclear response, especially the Gamow-Teller (GT) transitions starting from stable as well as unstable nuclei is one of the key issues in nuclear and nuclear-astrophysics. We studied the GT transitions by means of hadronic ( 3 He, t) charge-exchange reactions and complementary β decays. Owing to the simple στ nature of the operator that causes GT transitions, information on the crucial and critical part of the nuclear structure can be studied. Under the assumption that isospin is a good quantum number, symmetry is expected for the structure of mirror nuclei and the GT transitions starting from them. The results from β-decay studies and the strength distribution of GT transitions from the ( 3 He, t) reaction are compared and also combined for the understanding of nuclear structure of far-from-stability nuclei.

High-resolution study of Gamow-Teller excitations in theCa42(He3,t)Fujita1, Fujita2, Adachi3 et al. 2015Phys. Rev. CSelf Cite4291090View full textAdd to dashboardCite

“…In CE reactions, on the other hand, GT excitations can be studied up to high excitation energies. In particular, GT excitations become prominent at intermediate incident energies (above 100 MeV/nucleon) and forward angles around 0 • [4,10]. Since the 1980s, (p, n) reactions performed at incoming proton energies of E p = 120 − 200 MeV have been used for the study of GT transitions in the β − direction [10].…”

“…Gamow-Teller transitions are studied through β decays and charge exchange (CE) reactions [4]. Studies using β decay can provide the most direct information on the reduced GT transition strength B(GT).…”

“…The transitions are among the j > and j < shells such as f 7/2 and f 5/2 shells. Due to the simple character of the GT operator, GT transitions are important tools for the study of nuclear structure [1][2][3][4] as well as nuclear interactions [5][6][7][8]. In addition, GT transitions are the most common nuclear weak-interaction processes.…”

Electron-capture Rates for pf-shell Nuclei in Stellar Environments and Nucleosynthesis

“…The Gamow-Teller (GT) strength in 58 Ni [3], for example, is nicely reproduced and M1 strengths in various p f -shell nuclei are also well described. GXPF1J reproduces the energy of the 1 + state in 48 Ca.…”

“…Calculated e-capture rates for 56 Ni at high densities and temperatures as well as the ratio to KBF values are shown in Fig. 2 for densities ρY e = 10 7 − 10 9 g/cm 3 (Y e is the lepton-to-baryon ratio or proton fraction) and temperatures T =(0.1-10) or (0.01-10)×10 9 K. The KB3G gives larger capture rates compared to GXPF1J, while KBF rates are larger (smaller) at ρY e = 10 9 (10 8 ) g/cm 3 where the electron chemical potential is about 5.1 MeV (2.4 MeV). The ratio of the capture rates of GXPF1J relative to those of KBF depends on the densities as shown in Fig.…”