A long-standing problem in string phenomenology has been the fact that the string unification scale disagrees with the GUT scale obtained by extrapolating low-energy data within the framework of the minimal supersymmetric standard model (MSSM). In this paper we examine several effects that may modify the minimal string predictions and thereby bring string-scale unification into agreement with l...

According to astrophysical and cosmological observations, about 20 percent of the total energy in the universe is contributed by dark matter, which, within present observational limits, only exhibits gravitational interaction. Meanwhile, the Standard Model of elementary particles don’t contain such weakly-interacting constituents. To solve this mystery several schemes extending the Standard Mod...

In this article we have summarized the status of the system SANC version 0.41. We have implemented theoretical predictions for many high energy interactions of fundamental particles at the one-loop precision level for up to 4-particle processes. In the present part of our SANC description we place emphasis on an extensive discussion of an important first step of calculations of the one-loop amp...

From vehicle, gun, projectile and charge system, a basic principle has been presented for the first time in the paper by making use of the random-simulation technology based on the theory of interior ballistic, automat, vibration of self-propelled gun system, initial disturbing and external ballistic etc. The basic principle is achieved by simulating a movement procedure of the gun-vehicle syst...

We present an extended problem appropriate for students in a semester-long introductory elementary particle physics class. This problem requires them to synthesize concepts and investigative approaches learned throughout the class, directed toward answering the question of why muon-to-electron conversion experiments are proposed, but not electron-to-muon experiments. Although direct electron-to...

Average daily ultrafine particles (UFP) exposure of adult Milan subpopulations (defined on the basis of gender, and then for age, employment or educational status), in different exposure scenarios (typical working day in summer and winter) were simulated using a microenvironmental stochastic simulation model. The basic concept of this kind of model is that time-weighted average exposure is defi...

Momentum distribution of fragments produced in 12C+ 12C reaction at 28.7 MeV/nucleon is analyzed with antisymmetrized version of molecular dynamics (AMD). Calculations are made for several cases of stochastic collisions and the projectile fragmentation peak in momentum distribution is reproduced by the incorporation of many-body nature in stochastic collision process. Furthermore the value of t...

Abstract. The Higgs field is a central point of the Standard Model supplying masses to other fields through the symmetry breaking mechanism. However, it is associated with an elementary particle which is not yet discovered experimentally. In this short note I suggest a way for expressing the Higgs field through other fields of the Standard Model. If this is the case, being not an independent fi...

We assess the prospects for attaining steady nuclear flow equilibrium in expanding r-process environments where beta decay and/or neutrino capture determine the nuclear charge-changing rates. For very rapid expansions, we find that weak steady flow equilibrium normally cannot be attained. However, even when neutron capture processes freeze out in such nonequilibrium conditions, abundance ratios...

The constrained Hamiltonian formalism is recommended as a means for getting a grip on the concepts of gauge and gauge transformation. This formalism makes it clear how the gauge concept is relevant to understanding Newtonian and classical relativistic theories as well as the theories of elementary particle physics; it provides an explication of the vague notions of “local” and “global” gauge tr...