High-resolution study of Gamow-Teller transitions from theTz=1nucleusTi46

Abstract

The Gamow-Teller (GT) transition strengths in fp-shell nuclei are important parameters in presupernova models. A high-energy-resolution ( 3 He, t) experiment was performed on the T z = 1 nucleus 46 Ti at 0 • and at an intermediate incident energy of 140 MeV/nucleon for the study of precise GT transition strengths to the final T z = 0 nucleus 46 V. With an energy resolution of 33 keV, individual GT transitions were observed and GT strengths were derived for them up to the excitation energy of 4.5 MeV. The GT strengths were compared with shell-model calculations using various effective interactions. In this low-lying region, most GT states have isospin T = 0. A few GT states with isospin T = 1 were identified from the existence of the corresponding (analog) M1 states in 46 Ti. By comparing the GT strength with the corresponding (analogous) M1 transition strength studied in 46 Ti(e, e ) or (γ, γ ) measurements, a large constructive interference of orbital and spin terms was suggested for one of these M1 transitions.

High-resolution study of Gamow-Teller excitations in theCa42(He3,t)Fujita1, Fujita2, Adachi3 et al. 2015Phys. Rev. CSelf Cite4391090View full textAdd to dashboardCite

“…As a result, in the studies of GT excitations on T z = +1 target nuclei 54 Fe [20] and 58 Ni [21] performed up to E x ≈ 13 MeV, it was found that the bump-like structures of GTRs observed in (p, n) studies actually consist of many discrete states excited by GT transitions (GT states). The fragmented GT states were also observed in the studies of the other T z = +1 target nuclei 46 Ti [22] and 50 Cr [23] and in a recent study of the T z = +3/2 nucleus 47 Ti [24].…”

“…It is suggested that the fragmentation in this region is caused by the mixing with the sdshell configurations resulting from ground state correlations (see also the discussions in Refs. [22,32]). Note that this effect is not included in our SM calculation, since we assume an inert 40 Ca core.…”

High-resolution study of Gamow-Teller transitions in the47Ti(3He,t)Ganioğlu1, Fujita2, Fujita3 et al. 2013Phys. Rev. CSelf Cite

“…The A dependence of R 2 was systematically studied and a smooth increase in R 2 was observed as A increases [36,37]. A value of R 2 =8.1±0.4 can be deduced for the A = 47 nuclei by quadratically interpolating the experimentally obtained R 2 values for A = 26 [13], 34 [15], 46 [16], 54 [18], 64 [19], 78 [38], 118, and 120 [39]. The resulting B(GT) value obtained for the GT transition to the E x =4.150 MeV, IAS is shown in Table I.…”

“…On the basis of these observations, the strengths of GT transitions starting from the T z = +1, pf -shell nuclei 46 Ti, 50 Cr, 54 Fe, and 58 Ni, and also the T z = +4 nucleus 64 Ni have been intensively studied [11,[16][17][18][19]. The bump-like GTR structures consisting of many fragmented states were observed for nuclei A ≥ 54 but not for the nuclei A ≤ 50.…”

High-resolution study ofTz=+1→0Gamow-Teller transitions in theMg26(He

“…Fine structures are also reported in pf -shell nuclei 50 Mn, 54 Co, and 58 Cu (T z = 0) [35][36][37][38], 47 V (T z = +1/2) [39], 48 V and 60 Cu (T z = +1) [5,40], 62 Cu (T z = +2) [5], and 64 Cu (T z = +3) [5,41]. However, the GTR structure was not found in 42 Sc (T z = 0) [26] and was not clear in 46 V (T z = 0) [38,42] as well as 44 Sc (T z = +1) [43]. Note that the observed features of the strength distributions and the fragmented GTR structures are distinctively different in these sd-and pf -shell nuclei, showing a marked individuality of their structures (see the discussion in Refs.…”