Specific features of the photoconductivity of polymer film composites containing a heterometallic iron(II)/zinc(II) complex

The specific features of electric conductivity and photoconductivity in films of composites based on poly(vinyl alcohol) doped with the complex [Fe(bipy)₃][Zn(NCS)₄] (where bipy is 2,2′-bipyridyl) and the effect of magnetic field on these properties were studied. It was found that photocurrent decreases with an increase in the magnetic field strength up to 5.5 kOe. It was assumed that the photoconductivity of these composites and its dependence on magnetic field are affected by paramagnetic iron(III) complex particles produced as a result of internal photoelectric effect. The effect of magnetic field on the photoconductivity is associated with the spin-dependent recombination of photogenerated charge pairs.     

Merocyanine dye-sensitized photoconductivity of polymer composites based on heterometallic copper/iron complexes

The electric and photoconductive properties of films of polymer composites containing heterometallic complexes [Cu(phen)₂Fe(CN)₅NO]· 2H₂O or [Cu(phen)₂Br]₂[Fe(CN) ₅NO]DMF (where phen is 1,10-phenanthroline and DMF is dimethylformamide) and a merocyanine dye were studied. The photocurrent is greater for the bromide complex and increases upon introduction of a merocyanine dye into the composites. The photocurrent also increases upon the application of an external magnetic field and saturates in fields of <1 kOe. It is assumed that the sensitization of photoconductivity by the merocyanine dye is due to photogeneration of triplet charge pairs from dye molecules and transport of nonequilibrium charge carriers in and between the particles of the complexes, rather than to an increase in the absorbance.     

Neutrino production of charmed particles in a hybrid experiment E-564

Cryogenically sensitive nuclear emulsion was placed inside the 15-foot bubble chamber of FNAL and exposed to a wide-band energy (up to 200 GeV) neutrino beam. 194 charged-current neutrino interactions and 13 decays of charmed particles were registered. Using the nuclear emulsion as a vertex detector with the good spectrometric properties of the 15-foot bubble chamber has allowed the decays of charmed particles to be effectively analysed. Attentions is focussed on the new physical results. Λ _c ⁺ baryon andD _s ⁺ meson decay channels, production of charmed ∑ _c baryons and Λ _c ⁺ via ∑ _c . For the first time an event interpreted as production of the excited (c \(\overline s\) )-state with mass ～2790 MeV/c² has been registered.     

Enriched Zn $$^{100}$$ MoO $$_4$$ scintillating bolometers to search for $$0\nu 2\beta $$ decay of $$^{100}$$ Mo with the LUMINEU experiment

In the present work, we consider a model with a fermionic field that is non-minimally coupled to gravity in the framework of teleparallel gravity. In order to determine the forms of the coupling and potential function of fermionic field for the considered model, we use the Noether symmetry approach. By applying this approach, for the Friedman–Robertson–Walker metric, we obtain the respective potential and coupling functions as a linear and power-law form of the bilinear \(\Psi \) . Furthermore, we search for the exact cosmological solution of the model. It is shown that the fermionic field plays the role of dark energy.     

Barkas effect for antiproton stopping in H2

We report the stopping power of molecular hydrogen for antiprotons of kinetic energy above the maximum (approximately 100 keV) with the purpose of comparing with the proton one. Our result is consistent with a positive difference in antiproton-proton stopping powers above approximately 250 keV and with a maximum difference between the stopping powers of 21%+/-3% at around 600 keV.     

Rejection of randomly coinciding events in ZnMoO_4 scintillating bolometers

Random coincidence of events (particularly from two neutrino double beta decay) could be one of the main sources of background in the search for neutrinoless double beta decay with cryogenic bolometers due to their poor time resolution. Pulse-shape discrimination by using front edge analysis, mean-time and \(\chi ^2\) methods were applied to discriminate randomly coinciding events in ZnMoO \(_4\) cryogenic scintillating bolometers. These events can be effectively rejected at the level of 99 % by the analysis of the heat signals with rise-time of about 14 ms and signal-to-noise ratio of 900, and at the level of 92 % by the analysis of the light signals with rise-time of about 3 ms and signal-to-noise ratio of 30, under the requirement to detect 95 % of single events. These rejection efficiencies are compatible with extremely low background levels in the region of interest of neutrinoless double beta decay of \(^{100}\) Mo for enriched ZnMoO \(_4\) detectors, of the order of \(10^{-4}\)  counts/(y keV kg). Pulse-shape parameters have been chosen on the basis of the performance of a real massive ZnMoO \(_4\) scintillating bolometer. Importance of the signal-to-noise ratio, correct finding of the signal start and choice of an appropriate sampling frequency are discussed.     

Search for double- \beta decays of 96Ru and 104Ru by ultra-low background HPGe \gamma spectrometry

A search for double- $ \beta$ processes in ⁹⁶Ru and ¹⁰⁴Ru was realized in the underground Gran Sasso National Laboratories of the INFN (Italy) with the help of ultra-low background HPGe $ \gamma$ spectrometry. After 158h of data taking with 473g ruthenium sample, new improved limits on double-beta processes in ⁹⁶Ru have been established on the level of 10¹⁸-10¹⁹yr. For the first time the double-beta decay of ¹⁰⁴Ru to the 2⁺ ₁ excited level of ¹⁰⁴Pd has been restricted as T _1/2 > 3.5×10¹⁹ yr.