Prospects of detecting massive isosinglet neutrino at LHC in the CMS detector

A possibility to search for a heavy isosinglet (sterile) neutrino using its decay mode $\nu_s \to l^{\pm} + 2 jets$ in the $S$ - channel production $pp \to W^* + X \to l^{\pm}\nu_s + X$ in the CMS experiment is studied. The only assumption about the heavy neutrino is its nonzero mixing with $\nu_e$ or $\nu_{\mu}$. The corresponding CMS discovery potential expressed in terms of the heavy neutrino mass and the mixing parameter between the heavy and light neutrino is determined. It is shown that the heavy neutrino with a mass up to 800 $GeV$ could be detected in CMS. We also investigate the production of the heavy neutrino $N_l$ mixed with $\nu_e$ and/or $\nu_{\mu}$ in the $SU_C(3) \otimes SU_L(2) \otimes SU_R(2)\otimes U(1)$ model through the reaction $pp \to W_R + X \to l^{\pm}N_l + X$ with the same heavy neutrino decay channel as above. We find that for $M_{W_R} < 3 TeV$ it is possible to discover the heavy neutrino with a mass up to $0.75 \cdot M_{W_R}$.Comment: 14 pages, 13 figure

The exact tree-level calculation of the dark photon production in high-energy electron scattering at the CERN SPS

Dark photon ($A'$) that couples to the standard model fermions via the kinetic mixing with photons and serves as a mediator of dark matter production could be observed in the high-energy electron scattering $e^- + Z ~\rightarrow e^- + Z + A'$ off nuclei followed by the $A' \to invisible$ decay. We have performed the exact, tree-level calculations of the $A'$ production cross sections and implemented them in the program for the full simulation of such events in the experiment NA64 at the CERN SPS. Using simulations results, we study the missing energy signature for the bremsstrahlung $A' \rightarrow$ invisible decay that permits the determination of the $\gamma-A'$ mixing strength in a wide, from sub-MeV to sub-GeV, $A'$ mass range. We refine and expand our earlier studies of this signature for discovering $A'$ by including corrections to the previously used calculations based on the improved Weizsaker-Williams approximation, which turn out to be significant. We compare our cross sections values with the results from other calculations and find a good agreement between them. The possibility of future measurements with high-energy electron beams and the sensitivity to $A'$ are briefly discussed.Comment: 11 pages, 6 figures, revised version, improved cross-section integrator is used, comparison with bremsstrahlung spectrum is added, final conclusions remain unchange

Missing energy signature from invisible decays of dark photons at the CERN SPS

The dark photon ($A'$) production through the mixing with the bremsstrahlung photon from the electron scattering off nuclei can be accompanied by the dominant invisible $A'$ decay into dark-sector particles. In this work we discuss the missing energy signature of this process in the experiment NA64 aiming at the search for $A'\to invisible$ decays with a high-energy electron beam at the CERN SPS. We show the distinctive distributions of variables that can be used to distinguish the $A'\to invisible$ signal from background. The results of the detailed simulation of the detector response for the events with and without $A'$ emission are presented. The efficiency of the signal event selection is estimated. It is used to evaluate the sensitivity of the experiment and show that it allows to probe the still unexplored area of the mixing strength $10^{-6}\lesssim \epsilon \lesssim 10^{-2}$ and masses up to $M_{A'} \lesssim 1$ GeV. The results obtained are compared with the results from other calculations. In the case of the signal observation, a possibility of extraction of the parameters $M_{A'}$ and $\epsilon$ by using the missing energy spectrum shape is discussed. We consider as an example the $A'$ with the mass 16.7 MeV and mixing $\epsilon \lesssim 10^{-3}$, which can explain an excess of events recently observed in nuclear transitions of an excited state of $^8$Be. We show that if such $A'$ exists its invisible decay can be observed in NA64 within a month of running, while data accumulated during a few months would allow also to determine the $\epsilon$ and $M_{A'}$ parameters.Comment: 12 pages, 15 figures. Revised versio

Distributional Effects of Endogenous Discounting

Short communicationThis paper studies the effect of endogenous discounting on the distribution of wealth in a Bewley–Huggett economy with an exogenous borrowing constraint. We introduce the Koopmans–Uzawa–Epstein time preferences in the benchmark model of Achdou et al. (2022) and investigate the implications on saving behaviour and wealth distribution across different wealth classes. The results highlight a self-reinforcing redistribution mechanism, through which the endogenous discounting can lead to a higher equilibrium interest rate and a more unequal wealth distribution, in comparison to the benchmark model with constant discount rate

Legal Control Over Copyright Protection Using Blockchain Technology

The development of digital information technologies predetermined the need to develop technical and legal mechanisms of copyright protection. Now the share of copyright in the national economies of most countries is very significant and continues to grow, the main task of national legal systems is to find and implement technical and legal solutions to protect copyright from digital piracy. One of these solutions is block chain technology. The relevance of the research topic rests at the novelty of this technology and the lack of study of issues in the field of theory and law enforcement related to the adaptation and legitimation of relations using block chain technologies, including in the field of copyright protection. The purpose of this article is to analyze the legal qualifications of block chain technology and its application in the field of copyright protection, legitimization of relations associated with the use of block chain technologies in the field of copyright protection. The study revealed that the block chain has features that allow for classification of this technology as a type of technical means of copyright protection, which is the theoretical significance of this study. It has been established that in the field of copyright protection, the block chain performs the function of fixing and confirming the legitimacy of ownership by the author or other right holder of the corresponding work, and provides control over access to the work during authorized use. In the course of the study, the authors assessed the provisions of the current procedural legislation for the use of block chain technologies as evidence in court proceedings for copyright protection and revealed that information from the block chain, including those confirming authorship, can be recognized by the courts as evidence

ANALYSIS OF THE DEFLECTION OF A TRUSS WITH A DECORATIVE LATTICE

Introduction. A scheme is proposed for a planar symmetric statically determinate beam truss with a rectilinear lower belt, struts, multidirectional braces and a polygonal outline of the upper belt. The belts of the truss are rectilinear, the hinges are ideal. The truss belongs to the class of regular trusses having periodic cells. The supporting rods are not deformable. The truss is evenly loaded around the nodes of the lower belt. Materials and methods. The task is to deduce the dependence of the deflection of the truss on the number of panels in the span. The deflection is obtained from the Maxwell-Mora formula under the assumption that all the rods have the same rigidity. Forces in the structural rods from the effective uniform load and from the unit vertical in the middle of the span are determined by the method of cutting the nodes. The matrix of the system of linear equations of node equilibrium is made up of the cosines of the forces with the coordinate axes. To compile a system of equations and solve it, the program of symbolic mathematics Maple is used. To obtain the general formula, a number of problems of trusses with a number of panels from 2 to 29 are solved. Sequences of the coefficients of the deflection formula have common terms for which homogeneous recurrence equations are also compiled using the methods of the Maple system using specialized operators. Results. The solutions of recurrence equations have the form of polynomials with coefficients that depend on the parity of the number of panels and contain trigonometric functions. The graphs of the solutions obtained are constructed and analysed. Sharp changes of deflection characteristic for such truss and their non-monotonic character are noted. It is shown that for a fixed, independent on the number of panels, length of the span and the total load, the relative deflection with increasing number of panels first decreases, then varies little. Conclusions. The asymptotic property of the solution is obtained by the methods of the Maple system: an inclined asymptote is found. The slope is calculated using the analytical capabilities of Maple. A simple formula is derived for the horizontal displacement of the mobile support from the action of the load. The dependence is monotonic. The height of the truss is included in the denominator of the formula

ONE FEATURE OF THE CONSTRUCTIVE SOLUTIONS OF THE LATTICE GIRDER

The problem of the deflection of a planar symmetric statically determinable truss with a double lattice depending on the number of panels was solved in an analytical form. The angle of inclination of the ascending and descending rods of the truss is different. A load is applied to the truss, evenly distributed over the nodes of the lower chord. Special operators of the Maple computer math system and the induction method were used to generalize individual particular solutions to an arbitrary case. Formulas are obtained for the forces the most compressed and stretched truss rods. Cases of kinematic variability of the structure are revealed. A picture of the possible speeds of truss nodes in these cases is constructed. The asymptotic behavior of the deflection is found with a large number of panels and a fixed span length. The deflection was determined by the formula of Maxwell – Mohr

Probing lepton flavour violation in νμ+N→τ+...\nu_{\mu} + N \to \tau + ... scattering and μ→tau\mu \to tau conversion on nucleons

We study lepton flavour-violating interactions which could result in the $\tau$-lepton production in the $\nu_{\mu}N$ scattering or in $\mu \to \tau$ conversion on nucleons at high energies. Phenomenological bounds on the strength of $\bar{\tau}\nu_{\mu}\bar{q}q^{'}$ interactions are extracted from the combined result of the NOMAD and CHORUS experiments on searching for $\nu_{\mu} - \nu_{\tau}$ oscillations. Some of these bounds supersede limits from rare decays. We also propose a ``missing energy'' type experiment searching for $\mu - \tau$ conversion on nucleons. The experiment can be performed at a present accelerator or at a future neutrino factory.Comment: 13 pages, 4 figure

Applicability of QKD: TerraQuantum view on the NSA's scepticism

Quantum communication offers unique features that have no classical analog, in particular, it enables provably secure quantum key distribution (QKD). Despite the benefits of quantum communication are well understood within the scientific community, the practical implementations sometimes meet with scepticism or even resistance. In a recent publication [1], NSA claims that QKD is inferior to "quantum-resistant" cryptography and does not recommend it for use. Here we show that such a sceptical approach to evaluation of quantum security is not well justified. We hope that our arguments will be helpful to clarify the issue