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We study the effects of collective neutrino oscillations on νp process nucleosynthesis in proton-rich neutrino-driven winds by including both the multi-angle 3 × 3 flavor mixing and the nucleosynthesis network calculation. The number flux of energetic electron antineutrinos is raised by collective neutrino oscillations in a 1D supernova model for 40M⊙ progenitor. When the gas temperature decreases down to ∼ 2 − 3 × 10 9 K, the increased flux of electron antineutrinos promotes νp process more actively, resulting in the enhancement of p-nuclei. In the early phase of neutrino-driven wind, blowing at 0.6 s after core bounce, oscillation effects are prominent in process, which indicates that they should be included in the network calculations in order to obtain precise abundances of p-nuclei. The conclusions of this paper depend on the difference of initial neutrino parameters between electron and non-electron antineutrino flavors which is large in our case. Further systematic studies on input neutrino physics and wind trajectories are necessary to draw a robust conclusion. However, this finding would help understand the origin of solar-system isotopic abundances of p-nuclei such as 92,94 Mo and 96,98 Ru.

We calculate the Galactic Chemical Evolution of Mo and Ru by taking into account the contribution from ν p-process nucleosynthesis. We estimate yields of p-nuclei such as 92,94Mo and 96,98Ru through the ν p-process in various supernova progenitors based upon recent models. In particular, the ν p-process in energetic hypernovae produces a large amount of p-nuclei compared to the yield in ordinary core-collapse SNe. Because of this, the abundances of 92,94Mo and 96,98Ru in the Galaxy are significantly enhanced at [Fe/H] = 0 by the ν p-process. We find that the ν p-process in hypernovae is the main contributor to the elemental abundance of 92Mo at low metallicity [Fe/H] < −2. Our theoretical prediction of the elemental abundances in metal-poor stars becomes more consistent with observational data when the ν p-process in hypernovae is taken into account.

The purpose of this study is to have a better understanding of the unsteady behavior of tip clearance flow at near-stall condition from a multi-passage simulation and to clarify the relation between such unsteadiness and rotating disturbance. This study is motivated by the following concern. A single passage simulation has revealed the occurrence of the tip leakage vortex breakdown at near-stall condition in a transonic axial compressor rotor, leading to the unsteadiness of the tip clearance flow field in the rotor passage. These unsteady flow phenomena were similar to those in the rotating instability, which is classified in one of the rotating disturbances. In other words it is possible that the tip leakage vortex breakdown produces a rotating disturbance such as the rotating instability. Three-dimensional unsteady RANS calculation was conducted to simulate the rotating disturbance in a transonic axial compressor rotor (NASA Rotor 37). The four-passage simulation was performed so as to capture a short length scale disturbance like the rotating instability and the spike-type stall inception. The simulation demonstrated that the unsteadiness of tip leakage vortex, which was derived from the vortex breakdown at near-stall condition, invoked the rotating disturbance in the rotor, which is similar to the rotating instability.

In order to investigate the impact of collective neutrino oscillations (CNO) on the neutrino signal from a nearby supernova, we perform 3-flavor neutrino oscillation simulations employing the multiangle effect. The background hydrodynamic model is based on the neutrino hydrodynamic simulation of a 8.8 M⊙progenitor star. We find that CNO commences after some 200 ms post bounce. Before this, CNO is suppressed by matter-induced decoherence. In the inverted mass hierarchy, the spectrum ofνe becomes softer after the onset of CNO. To evaluate the detectability of this modification, we define a hardness ratio between the number of high energy neutrino events and low energy neutrino events. We show that Hyper-Kamiokande (HK) can distinguish the effect of CNO for supernova distances out to ∼ 10 kpc. On the other hand, for the normal mass hierarchy, the spectrum of νe becomes softer after the onset of CNO, and we show that DUNE can distinguish this feature for supernova distances out to ∼ 10 kpc. Furthermore, we show that if the spectrum of νe in HK becomes softer due to CNO, the spectrum of νe in DUNE becomes harder, and vice versa. This synergistic observations inνe and νe, by HK and DUNE respectively, will be an intriguing opportunity to test the occurrence of CNO.

We calculate the abundances of 7Li, 11B, 92Nb, 98Tc, 138La, and 180Ta produced by neutrino (ν)-induced reactions in a core-collapse supernova explosion. We consider the modification by ν self-interaction (ν-SI) near the neutrinosphere and the Mikheyev–Smirnov–Wolfenstein (MSW) effect in the outer layers based on time-dependent neutrino energy spectra. Abundances of 7Li and the heavy isotopes 92Nb, 98Tc, and 138La are reduced by a factor of 1.5–2.0 by the ν-SI. In contrast, 11B is relatively insensitive to the ν-SI. We find that the abundance ratio of heavy to light nuclei, 138La/11B, is sensitive to the neutrino mass hierarchy, and the normal mass hierarchy is more likely to be consistent with the solar meteoritic abundances.

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