Search

Despite the undeniable success of the standard model of particle physics (SM), there are some phenomena that the SM cannot explain. These phenomena indicate that the SM has to be modified. One of the possible ways to extend the SM is to introduce heavy neutral leptons (HNLs). To search for HNLs in intensity Frontier experiments, one has to consider HNL production both in two-body and three-body decays of some mesons. We verified the possibility of using the parton level PYTHIA default matrix elements (without the form-factor formalism) to calculate HNL production in three-body semileptonic decays of B and D mesons in the experimentally interesting mass range of the produced HNLs. We conclude that this approach is quite suitable for the estimation of the sensitivity region for HNLs in the intensity Frontier experiments, provided one uses suitable parton level PYTHIA default matrix elements. Our study was driven by the usage of such an approximation by the SHiP collaboration. We conclude that in this case the parton level PYTHIA default matrix elements could have been chosen more appropriately. [ABSTRACT FROM AUTHOR]

We consider the effect of the magnetic field background in the form of a tube of the finite transverse size on the vacuum of the quantized charged massive scalar field which is subject to the Dirichlet boundary condition at the edge of the tube. The vacuum energy is induced, being periodic in the value of the magnetic flux enclosed in the tube. The dependence of the vacuum energy density on the distance from the tube and on the coupling to the space-time curvature scalar is comprehensively analyzed. [ABSTRACT FROM AUTHOR]

The article presents a study on phosphorous cast iron for heat-resistant castings. Phosphorus is known to have a substantial influence on the structure and mechanical properties of castings and on their service life. The high segregation susceptibility of phosphorus leads to the formation of a low-melting phosphorus eutectic. In recent years, frequent instability of the chemical composition of charges has led to a situation where iron molds were cast from metal bearing more than 0.2 percent phosphorus. However, in some cases the heat resistance of the molds did not decrease but even went up. The authors have devoted the present study to explaining this phenomenon and developing a composition of phosphorous cast iron.