Isotopes of $^{100}$Mo, $^{82}$Se and experiments NEMO, MOON, AMoRE
Isotopes of $^{100}$Mo, $^{82}$Se and experiments NEMO, MOON, AMoRE
Prokhorov A. A.
Double beta decay is a very rare nuclear decay and has double and neutrinoless modes of decay. This article describe the search of neutrinoless double beta decay in modern experiments NEMO, MOON, AMoRE. In these experiments are used different type of detectors and methods of registration, so the search for this decay have a different sensitivity to its half-life. The article also discussed the detectors, their features and prospects for their modernization for increasing sensitivity to neutrinoless beta decay.
Show AbstractNeutrino oscillations
Neutrino oscillations
Shirokov E.V.
Neutrino oscillations is one of the main questions in modern physics of weak interactions. Neutrinos are uncharged leptons, i.e. particles of the Standard Model that do not participate in the strong interaction. They can be divided into three types (or, as they say, three flavors), in accordance with the classification of the charged leptons. This electron, muon and taon neutrinos. Oscillations are the processes of conversion from one type of neutrino to another. The oscillations occupy an extremely important place in modern neutrino physics, because they can answer the question of the neutrino mass existence. Recently, intensive experimental study of this phenomenon is conducted. A significant part of the modern neutrino experiments in some way connected with the study of neutrino oscillations.
Show AbstractTheoretical efforts to predict half-lives of double beta decay
Theoretical efforts to predict half-lives of double beta decay
Khirk M. S.
Double beta decay ($2\nu\beta\beta$) is a very rare nuclear process. The reason of the rarity of such decay is the second order forbiddance in the Standard Model of electroweak interactions for this process. Over the last 80 years two-neutrino double beta decay have been observed in 12 nuclei and their half-lives range from $10^{19}$ to $10^{24}$ years. This article is concerned with methods of theoretical calculations of half-lives of double beta decay. Also some attempts to describe the experimental data using empirical formulas are under consideration.
Show AbstractNd-150 isotope, DCBA experiment
Nd-150 isotope, DCBA experiment
Kurov E. A.
The DCBA (Drift Chamber Beta-ray Analyzer) experiment is a project aimed at discovering of neutrinoless double beta decay in isotopes of Nd-150 and Se-82; that utilizes a track chamber with a Superconducting Solenoid Magnet (SCSM). Further search for $0\nu\beta\beta$ with increasing half-life ranging to the order of $10^{26}$~s is possible by means of the MTD (Magnetic Tracking Detector) project, which is a follow-up prototype based upon the DCBA experiment. Presently the development of the MTD project is halted due to the technical difficulty of obtaining Nd-150 of suf-ficient enrichment factor.
Show AbstractThe isotope $^{48}$Ca. CANDLES and CARVEL experiments
The isotope $^{48}$Ca. CANDLES and CARVEL experiments
Zavertkin K. A.
In the article isotope $^{48}$Ca for observing double beta decay has been considered. Also launched experiment CANDLES and the experiment CARVEL, which is in the project stage, has been considered. Structure of detectors, their characteristics, methods of detection has been presented. Particular attention has been paid to the background processes for both experiments. Experimental sensitivity to double beta decay in the case CANDLES and simulation results for CARVEL has been presented.
Show AbstractBrief introduction to the theory of Majorana neutrino
Brief introduction to the theory of Majorana neutrino
Mosharev P. A.
In the article it is shown, why and how in quantum field theory neutrino masses of Dirac and Majorana types are occurs and how classical experiments are consistent with the assumption of real neutrality of the neutrino. A review of the academic literature on this topic is given.
Show AbstractThe isotope $^{136}$Xe. EXO, NEXT, KamLAND-Zen experiments
The isotope $^{136}$Xe. EXO, NEXT, KamLAND-Zen experiments
Kiselev M. D.
The article is dedicated to one of the most actual problems of modern nuclear physics - the study of the very rare decay mode known as double beta decay by the example of xenon-136 isotope. The article describes the principles of experimental observation of this decay mode with leading experiments in this field: EXO, NEXT and KamLAND-ZeN. There are schematics and description of the main parts of the experimental units. Also, the experimental results and their comparison are illustrated.
Show AbstractDouble beta decay
Double beta decay
Ishkhanov B.S.
Double beta decay can occur near the bottom part of the mass valley where a given nucleus $(A,Z)$ has an adjacent nucleus $(A,Z+1)$ with higher mass while the nucleus $(A,Z+2)$ has a lower mass corresponding to an energy difference $\Delta E$. Double beta decay does exist as a second order decay process. The lifetimes estimated are typically of the order $T\approx 10^{20}$ y. Double beta decay carries a number of very intriguing aspects related to neutrino properties. Double beta decay has been observed both by geochemical methods and with counters.
Show AbstractGeometric phase transition in the problem of brachistochrone
Geometric phase transition in the problem of brachistochrone
Gladkov S.O., Bogdanova S.B.
It is found analytical solution of problem I. Bernoulli on the brahistohrone with frictional forces (viscous, proportional to speed motion and dry). It is shown that its solution is represented only in the form quadratures. With the aid of the numerical calculation are given different figures of optimum trajectories under dissipation conditions. It is proven that in the absence frictional forces any motion along the curvilinear chute under the action only of gravitational force is always reduced to the task about the brahistohrone. It is found the point “geometric phase transition”. This point corresponds to the disruption of brahistohrones from one class of trajectories to qualitatively another class. It is shown that with steady state the trajectory takes the form of the usual parabola, motion along which is periodically like the pendulum.
Show AbstractStudy of the unit “Rotational motion of a rigid body” in the course of general physics
Study of the unit “Rotational motion of a rigid body” in the course of general physics
D.V. Belov, A.S. Nifanov, I.M. Sraeva
This paper is a preamble to the detailed presentation of the classical mechanics unit “Rotational motion of a rigid body” for minor students in higher school. It clarifies the meaning of notions and definitions used in this unit, such as the rotational motion about an axis, moment of inertia, angular momentum, instantaneous axis of rotation, ellipsoid of inertia, and inertia tensor.
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