Minimisation of a one-loop charge breaking effective potential

We compute the field derivatives of a one-loop charge breaking effective potential and analyse their effect in its minimisation. The impact on charge breaking bounds on the MSSM parameters is discussed.Comment: 12 pages, 3 figures. One figure added and conclusions made cleare

Probing Radiative Solar Neutrinos Decays

Motivated by a pilot experiment conducted by F.Vannucci et al. during a solar eclipse, we work out the geometry governing the radiative decays of solar neutrinos. Surprisingly, although a smaller proportion of the photons can be detected, the case of strongly non-degenerate neutrinos brings better limits in terms of the fundamental couplings. We advocate satellite-based experiments to improve the sensitivity.Comment: 11 pages, 2 Postscript figure

Business Model of Sustainable Robo-Advisors: Empirical Insights for Practical Implementation

The given research paper examines the characteristics of German private investors regarding the probability of using robo-advisory-services. The used data set was gathered for this purpose (N = 305) to address the research question by using a logistic regression approach. The presented logit regression model results indicate that the awareness of sustainable aspects make a significant difference in the probability of using a sustainable robo-service. Additionally, our findings show that being male and cost-aware are positively associated with the use of a sustainable robo-advisor. Furthermore, the probability of use is 1.53 times higher among young and experienced investors. The findings in this paper provide relevant research findings for banks, asset managers, FinTechs, policy makers and financial practitioners to increase the adoption rate of robo-advice by introducing a sustainable offering

A full one-loop charge symmetry breaking effective potential

We calculate the one-loop contributions to the effective potential for the minimal supersymmetric model when scalar fields other than the Higgses have vacuum expectation values. The importance of these contributions for studies of charge and colour breaking bounds is discussed.Comment: 11 pages, 2 figure

Neutral minima in two-Higgs doublet models

We study the neutral minima of two-Higgs doublet models, showing that these potentials can have at least two such minima with different depths. We analyse the phenomenology of these minima for the several types of two-Higgs doublet potentials, where CP is explicitly broken, spontaneously broken or preserved. We discover that it is possible to have a neutral minimum in these potentials where the masses of the known particles have their standard values, with another deeper minimum where those same particles acquire different masses.Comment: 20 pages, 3 figure

Influence of Dark Matter on Light Propagation in Solar System

We investigated the influence of dark matter on light propagation in the solar system. We assumed the spherical symmetry of spacetime and derived the approximate solution of the Einstein equation, which consists of the gravitational attractions caused by the central celestial body, i.e. the Sun, and the dark matter surrounding it. We expressed the dark matter density in the solar system in the following simple power-law form, $\varrho(t, r) = \rho(t)(\ell/r)^k$, where $t$ is the coordinate time; $r$, the radius from the central body; $\ell$, the normalizing factor; $k$, the exponent characterizing $r$-dependence of dark matter density; and $\rho(t)$, the arbitrary function of time $t$. On the basis of the derived approximate solution, we focused on light propagation and obtained the additional corrections of the gravitational time delay and the relative frequency shift caused by the dark matter. As an application of our results, we considered the secular increase in the astronomical unit reported by Krasinsky and Brumberg (2004) and found that it was difficult to provide an explanation for the observed $d{\rm AU}/dt = 15 \pm 4 ~[{\rm m/century}]$.Comment: 18 pages, 4 figures, accepted for publication in Advances in Space Researc

Realistic Neutrino Masses from Multi-brane Extensions of the Randall-Sundrum Model?

Scenarios based on the existence of large or warped (Randall-Sundrum model) extra dimensions have been proposed for addressing the long standing puzzle of gauge hierarchy problem. Within the contexts of both those scenarios, a novel and original type of mechanism generating small (Dirac) neutrino masses, which relies on the presence of additional right-handed neutrinos that propagate in the bulk, has arisen. The main objective of the present study is to determine whether this geometrical mechanism can produce reasonable neutrino masses also in the interesting multi-brane extensions of the Randall-Sundrum model. We demonstrate that, in some multi-brane extensions, neutrino masses in agreement with all relevant experimental bounds can indeed be generated but at the price of a constraint (stronger than the existing ones) on the bulk geometry, and that the other multi-brane models even conflict with those experimental bounds.Comment: 29 pages, 3 figures, Latex file. References added, study extende

Role of beam polarization in the determination of WWγWW\gamma and WWZWWZ couplings from e+e−→W+W−e^+e^-\to W^+W^-

We evaluate the constraints on anomalous trilinear gauge-boson couplings that can be obtained from the study of electron-positron annihilation into $W$ pairs at a facility with either the electron beam longitudinally polarized or both electron and positron beams transversely polarized. The energy ranges considered in the analysis are the ones relevant to the next-linear collider and to LEP~200. We discuss the possibilities of a model independent analysis of the general $CP$ conserving anomalous effective Lagrangian, as well as its restriction to some specific models with reduced number of independent couplings. The combination of observables with initial and final state polarizations allows to separately constrain the different couplings and to improve the corresponding numerical bounds.Comment: 24 pages, LaTeX, 9 figures (available on request from the authors

The influence of additives on the fate of plastics in the marine environment, exemplified with barium sulphate

With an inherent density marginally below that of seawater, polyolefins (polyethylene-polypropylene) are predicted to float or undergo beaching in the marine environment. Polyolefins commonly observed on the seabed, therefore, require additional considerations that are usually based around increasing density through fouling or packaging into sinking faecal matter. Here, however, we propose that the presence of additives is of least equal significance to the behaviour of such plastics in marine systems. We compared barium, present largely as the filler, BaSO₄ (density = 4.5 g cm⁻³), in consumer and beached plastics and established that the metal was more abundant and occurred at higher concentrations in the former samples, consistent with the environmental fractionation of plastics based on additive content. Significantly, the Ba content of polyolefins required to confer a density above seawater is about 13,000 mg kg⁻¹, a value that was exceeded in many consumer plastics but never observed in beached samples