Prediction of |V_{13}| and the Dirac phase in the Neutrino Mixing Matrix

We considered a model where |V_{13}|=0 so that delta=0 at M_R and analyzed mixing angles and CP violation angles at the low energy scale by using the renormalization group in the MSSM model. In this model, parameters at M_R scale are two mixing angles (theta_{12} and theta_{23}), three neutrino masses, and two Majorana phases. We found that (1) sin^2 2 theta_{12} at the low energy scale must be less than that at $M_R$ scale, (2) the induced |V_{13}| can be as large as 0.05 if masses of neutrinos are around 0.05 eV.Comment: 4 pages, 2 figures, elsart.cls, a talk given at PANIC02, Osaka, September, 200

Development of a liquid scintillator containing a zirconium β-keto ester complex for the ZICOS experiment

AbstractA liquid scintillator containing a zirconium β-keto ester complex has been developed for the ZIrconium Complex in Organic Scintillator (ZICOS) neutrinoless double beta decay experiment. We are aiming to develop a detector which has a good energy resolution (4% at 2.5 MeV), a large light yield (60% that of BC505) and a low background rate (0.1 counts/tonne⋅year) with several tonnes of 96Zr isotope, so we have investigated the zirconium β-keto ester complexes tetrakis(isopropyl acetoacetato)zirconium and tetrakis(ethyl acetoacetato)zirconium, which have high solubility (over 10 wt.%) in anisole. We measured the performance of liquid scintillators containing these zirconium β-keto ester complexes and obtained 40% of the light yield of BC505 and energy resolution of 4.1% at 2.5 MeV assuming 40% photo coverage of the photomultiplier in the ZICOS detector. Thus we almost achieved our initial goal. Preliminary investigations indicate that tetrakis(diethyl malonato)zirconium will give us no quenching of the light yield and an energy resolution of 2.9% at 2.5 MeV. This will be a suitable complex for the ZICOS experiment, if it has a large solubility

Formation and reinforcement of clusters composed of C60 molecules

We carry out two experiments: (1) the formation of clusters composed of C60 molecules via self-assembly and (2) the reinforcement of the clusters. Firstly, clusters such as fibres and helices composed of C60 molecules are produced via self-assembly in supercritical carbon dioxide. However, C60 molecules are so weakly bonded to each other in the clusters that the clusters are broken by the irradiation of electron beams during scanning electron microscope observation. Secondly, UV photons are irradiated inside a chamber in which air is filled at 1 atm and the above clusters are placed, and it was found that the clusters are reinforced; that is, they are not broken by electron beams any more. C60 molecules located at the surface of the clusters are oxidised, i.e. C60On molecules, where n = 1, 2, 3 and 4, are produced according to time-of-flight mass spectroscopy. It is supposed that oxidised C60 molecules at the surface of the clusters may have an important role for the reinforcement, but the actual mechanism of the reinforcement of the clusters has not yet been clearly understood and therefore is an open question

Search for Tetraneutron by Pion Double Charge Exchange Reaction at J-PARC

Tetraneutron ($^4n$) has come back in the limelight, because of recent observation of a candidate resonant state at RIBF. We propose to investigate the pion double charge exchange (DCX) reaction, i.e. $^4\mathrm{He}({\pi}^- , {\pi}^+)$, as an alternative way to populate tetraneutron. An intense ${\pi}^-$ beam with the kinetic energy of ~850 MeV, much higher than that in past experiments at LAMPF and TRIUMF, will open up a possibility to improve the experimental sensitivity of the formation cross section, which will be much smaller than hitherto known DCX cross sections such as $^9\mathrm{Be}({\pi}^-, {\pi}^+)^9\mathrm{He}\ (g.s.)$.Comment: 4 pages, 1 figure; proceedings of the 14th International Conference on Meson-Nucleon Physics and the Structure of the Nucleon (MENU2016), Kyoto, Japan, 25-30 July 201

Relationships between feeding behaviors and emotions : an electroencephalogram (EEG) frequency analysis study

Feeding behaviors may be easily affected by emotions, both being based on brain activity; however, the relationships between them have not been explicitly defined. In this study, we investigated how emotional environments modulate subjective feelings, brain activity, and feeding behaviors. Electroencephalogram (EEG) recordings were obtained from healthy participants in conditions of virtual comfortable space (CS) and uncomfortable space (UCS) while eating chocolate, and the times required for eating it were measured. We found that the more participants tended to feel comfortable under the CS, the more it took time to eat in the UCS. However, the EEG emergence patterns in the two virtual spaces varied across the individuals. Upon focusing on the theta and low-beta bands, the strength of the mental condition and eating times were found to be guided by these frequency bands. The results determined that the theta and low-beta bands are likely important and relevant waves for feeding behaviors under emotional circumstances, following alterations in mental conditions

Performance of a liquid scintillator containing a zirconium β-keto ester complex developed for the ZICOS experiment

A liquid scintillator containing a zirconium β-keto ester complex has been developed for the ZIrconium Complex in Organic Scintillator (ZICOS) neutrinoless double beta decay experiment. We are aiming to develop a detector which has a good energy resolution (4% at 2.5 MeV), a large light yield (60% that of BC505) and a low background rate (0.1 counts/tonne・year) with several tonnes of 96Zr isotope, so we have investigated the zirconium β-keto ester complexes tetrakis (isopropyl acetoacetato) zirconium and tetrakis (ethyl acetoacetato) zirconium, which have high solubility (over 10 wt.%) in anisole. We measured the performance of liquid scintillators containing these zirconium β-keto ester complexes and obtained 40% of the light yield of BC505 and energy resolution of 4.1% at 2.5 MeV assuming 40% photo coverage of the photomultiplier in the ZICOS detector. Thus we almost achieved our initial goal. Preliminary investigations indicate that tetrakis (diethyl malonato) zirconium will give us no quenching of the light yield and an energy resolution of 2.9% at 2.5 MeV. This will be a suitable complex for the ZICOS experiment, if it has a large solubility

High Sensitivity Sensors Made of Perforated Waveguides

Sensors based on surface plasmons or waveguide modes are at the focus of interest for applications in biological or environmental chemistry. Waveguide-mode spectra of 1 μm-thick pure and perforated silica films comprising isolated nanometric holes with great aspect ratio were measured before and after adhesion of streptavidin at concentrations of 500 nM. The shift of the angular position for guided modes was nine times higher in perforated films than in bulk films. Capturing of streptavidin in the nanoholes is at the origin of that largely enhanced shift in the angular position as the amplitude of the guided mode in the waveguide perfectly overlaps with the perturbation caused by the molecules. Hence, the device allows for strongly confined modes and their strong perturbation to enable ultra-sensitive sensor applications