The Gamow-Teller strength distributions below the particle threshold in 138La and 180Ta, deduced from high-resolution measurements of the (3He,t) reaction at 0 degrees, allow us to evaluate the role of charged-current reactions for the production of these extremely rare nuclides in neutrino-nucleosynthesis models. The analysis suggests that essentially all 138La in the Universe can be made that way. Neutrino nucleosynthesis also contributes significantly to the abundance of 180Ta but the magnitude depends on the unknown branching ratio for population of the long-lived isomer.

Three titanomagnetite samples, of composition x = 0.7, 0.9, and 1.0 (where x is the ulvSspinel molecular fraction), were oxidized according to the method of Sakamoto et al., namely, wetgrinding followed by heating to 200-300øC. Like the samples of Sakamoto et al., our samples showed reversal of saturation magnetization during alteration of titanomagnetite to titanomaghemite. Our experimental results seem to be compatible neither with the ionic model of Verhoogen nor with the model of O'Reilly and Banerjee. The Curie point gradually increased and the lattice parameter decreased during low-temperature oxidation (titanomaghemitization). On heating above 300øC, the •-titanomaghemites underwent high-temperature oxidation (unmixing into magnetite, pseudobrookite, which is formed only during heating to 600øC, and rutile phases). The unmixing results in a sudden increase in Curie point and decrease in lattice parameter and saturation magnetization. On further heating, the saturation magnetization reverses for a second time. Therefore, double self-reversal of remanent magnetization in naturally oxidized rocks is considered a real possibility.Titanomaghemite is a major ferromagnetic constituent in some rocks, for example, submarine basalt. Therefore, it is important to study its magnetic properties.

The isovector transitions from the ground state (g.s.) of 16 O to the negative parity states in 16 F, i.e., the J π = 0 − g.s., the 0.193 MeV, 1 − state, the 0.424 MeV, 2 − state, the 0.721 MeV, 3 − state, and the 4 − "stretched" state at 6.372 MeV, were studied by using a high resolution 16 O( 3 He,t) 16 F reaction at 140 MeV/nucleon. With the help of high energy resolution, these states were, for the first time, clearly resolved in a charge exchange reaction at an intermediate energy, which favorably excites spin-flip states. Angular distributions of the reaction cross sections were measured in the laboratory frame from 0 • to 14 • . Parameters of phenomenological effective interactions were derived so as to reproduce these angular distributions in distorted wave Born approximation (DWBA) calculations. The angular distribution of the 0 − state could be reproduced well at θ c.m. < 10 • . The empirical values, however, are larger by a factor of 2-2.5 in the larger angle region, where the contribution of the so-called "condensed pion field" is expected. The high resolution also enabled the decay widths of these states to be measured.

Erratum: High-resolution study of Gamow-Teller transitions with the 37 Cl( 3 He, t) 37 Ar reaction [Phys. Rev. C 86, 024312 (2012)]

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