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The article provides a theoretical substantiation for a significant increase in the level of accuracy in determining the neutron lifetime using an alternative concept of neutron beta decay. Neutrons are distributed among different subsets depending on the sign of the scalar product of the neutron spin vector and momentum of the emitted electron during decay. Therefore, the neutron lifetime can be determined separately for each of the subsets as the inverse frequency of its decay, which is to be averaged over the number of neutrons in this subset. The total neutron lifetime on the total set of neutrons is calculated by averaging the partial (basic) lifetimes, considering their weights. The weights of the basic lifetimes are calculated for two weighing methods, leading, respectively, to the so-called lifetime of "nonpolarized" neutrons, the weighted average lifetime of neutrons and the central lifetime, i.e. the arithmetic mean for the basic lifetimes of neutrons. The dependence between different average neutron lifetimes through the integral asymmetry parameter calculated by using known experimental data leads to simple analytical expressions. The numerical estimate of the weighted average neutron lifetime gives a value that is in good agreement with the results of well-known experiments, which proves the validity of the proposed concept of neutron beta decay. This article includes necessary conditions for a new experiment to bring the neutron lifetime determination to a new level of accuracy., Comment: 17 pages, no figures, 18 references

The author considers a hypothesis of neutron lifetime splitting in beta-decay and shows that the beta-decay of neutrons could be described by the triad of lifetimes tau_{Left}, tau_{Mean}, tau_{Right}. The lifetime tau_{Left} is the lifetime of L-neutrons emitting electrons against the neutron spin direction (L-type neutron decay). The lifetime tau_{Right} is the lifetime of R-neutrons emitting electrons in the direction of the neutron spin (R-type neutron decay). The lifetime tau_{Mean} is the arithmetic average of tau_{Left}, tau_{Right} or the mean neutron lifetime. While using the parameters of electron-spin asymmetry of neutron decay and the results for determining the mean neutron lifetime, the performed numerical estimates gave the numerical values of the triad tau_{Left}, tau_{Mean}, tau_{Right} as 813 s, 900 s and 987 s respectively. In addition to the estimates, the lifetimes of the triad are determined from experimental data applying the decay scale tuning method proposed by the author. The experimental values of the triad coincided with the estimates with high accuracy. The weighted average neutron lifetime tau_{W} determined from the experimental neutron lifetimes tau_{Left} and tau_{Right} is equal to tau_{W}=833.33 +- 0.02 s, and is in good agreement with the values of the neutron lifetime obtained by the other methods., Comment: 13 pages, 4 figures

We explore recent estimations of the Hubble parameter $H$ depending on redshift $z$, which include 31 $H(z)$ data points measured from differential ages of galaxies and 26 data points, obtained with other methods. We describe these data together with Union 2.1 observations of Type Ia supernovae and observed parameters of baryon acoustic oscillations with 2 cosmological models: the standard cold dark matter model with the $\Lambda$ term ($\Lambda$CDM) and the model with generalized Chaplygin gas (GCG). For these models with different sets of $H(z)$ data we calculate two-parameter and one-parameter distributions of $\chi^2$ functions for all observed effects, estimate optimal values of model parameters and their $1\sigma$ errors. For both considered models the results appeared to be strongly depending on a choice of Hubble parameter data sets if we use all 57 $H(z)$ data points or only 31 data points from differential ages. This strong dependence can be explained in connection with 4 $H(z)$ data points with high redshifts $z>2$., Comment: 15 pages, 5 figures, published in Mathematical Modelling and Geometry, http://mmg.tversu.ru

We reveal the nature of transport and ferromagnetic properties of the GaAs structure with the single Mn {\delta}-doped layer. To modify the properties of the structure the electrically active radiation defects are created by irradiation with helium ions. The investigations show that the transport properties of the structure are determined by two parallel conduction channels (the channel associated with hole transport in the valence band and the channel associated with electron transport in the Mn impurity band) and that the ferromagnetic properties are determined by the electrons localized at the allowed states within the Mn impurity band. The results also help to understand the features of structures with the Mn {\delta}-layer nearby the quantum well.

Gamma-ray haloes can exist around galaxies due to the interaction of escaping galactic cosmic rays with the surrounding gas. We have searched for such a halo around the nearby giant spiral Andromeda galaxy M31 using almost 7 years of Fermi LAT data at energies above 300 MeV. The presence of a diffuse gamma-ray halo with total photon flux $2.6\pm 0.6\times 10^{-9}$ cm$^{-2}$~s$^{-1}$, corresponding to a luminosity (0.3-100 GeV) of $(3.2\pm 0.6)\times 10^{38}$ erg s$^{-1}$ (for a distance of 780~kpc) was found at a 5.3$\sigma$ confidence level. The halo form does not correspond to the extended baryonic HI disc of M31, as would be expected in hadronic production of gamma photons from cosmic ray interaction, nor it is spherically symmetric, as could be in the case of dark matter annihilation. The best-fit halo template corresponds to two 6-7.5 kpc bubbles symmetrically located perpendicular to the M31 galactic disc, similar to the 'Fermi bubbles' found around the Milky Way centre, which suggests the past activity of the central supermassive black hole or a star-formation burst in M31., Comment: 8 pages, 8 figures, strongly revised and extended version of 1501.03460. Accepted to MNRAS Letters. arXiv admin note: substantial text overlap with arXiv:1501.03460

Theories of galaxy formation predict the existence of extended gas halo around spiral galaxies. If there are 10-100 nG magnetic fields at several ten kpc distances from the galaxies, extended galactic cosmic ray (CR) haloes could also exist. Galactic CRs can interact with the tenuous hot halo gas to produce observable gamma-rays. We have performed search for a gamma-ray halo around the M31 galaxy -- the closest large spiral galaxy. Our analysis of almost 7 years of the Fermi LAT data revealed the presence of a spatially extended diffuse emission excess around M31. The data can be fitted using the simplest morphology of a uniformly bright circle. The best fit gave a 4.7$\sigma$ significance for a $0.9^{\circ}$ (12 kpc) halo with a photon flux of $\sim (3.2\pm1.0)\times 10^{-9} ~\mathrm{cm^{-2}s^{-1}}$ and a luminosity of $(4.0\pm1.5)\times 10^{38} ~\mathrm{erg~s^{-1}}$ in the energy range 0.3--100 GeV. Our results also imply a low level of the flux from the disc of the M31 galaxy $(3.3 \pm 1.0) \times 10^{-10}~\mathrm{cm^{-2}s^{-1}}$. The corresponding gamma-ray luminosity, $5\times10^{37} ~\mathrm{erg~s^{-1}}$ is several times smaller than the luminosity of the Milky Way. This difference could be explained by a lower star formation rate in M31: there are less CRs and the level of the ISM turbulence is lower, which in turn leads to a shorter time of CR containment., Comment: 5 pages, 5 figures. Pass 8 Reprocessed reconstruction and the 3FGL catalogue is used in this version of the paper

We have detected new components in stationary emission lines of SS 433; these are the superbroad components that are low-contrast substrates with a width of 2000--2500 km s-1 in He I $\lambda4922$ and H$\beta$ and 4000--5000 km s-1 in He II $\lambda4686$. Based on 44 spectra taken during four years of observations from 2003 to 2007, we have found that these components in the He II and He I lines are eclipsed by the donor star; their behavior with precessional and orbital phases is regular and similar to the behavior of the optical brightness of SS 433. The same component in H$\beta$ shows neither eclipses nor precessional variability. We conclude that the superbroad components in the helium and hydrogen lines are different in origin. Electron scattering is shown to reproduce well the superbroad component of H$\beta$ at a gas temperature of 20--35 kK and an optical depth for Thomson scattering $\tau \approx$ 0.25--0.35. The superbroad components of the helium lines are probably formed in the wind from the supercritical accretion disk. We have computed a wind model based on the concept of Shakura-Sunyaev supercritical disk accretion. The main patterns of the He II line profiles are well reproduced in this model: not only the appearance of the superbroad component but also the evolution of the central two-component part of the profile of this line during its eclipse by the donor star can be explained., Comment: 17 pages, 13 figures, 2 tables, published in Astronomy Letters, 2013, vol. 39, N 12, pp. 826 - 843