Stability of Neutrino Mass Degeneracy

Two neutrinos of Majorana masses $m_{1,2}$ with mixing angle $\theta$ are unstable against radiative corrections in the limit $m_1 = m_2$, but are stable for $m_1 = -m_2$ (i.e. opposite CP eigenstates) with $\theta = 45^\circ$ which corresponds to an additional symmetry.Comment: 7 pages, no figure, one reference adde

Application of the relocation-error distribution on geomagnetic databases. Analyses on the «Historical Italian Geomagnetic Data Catalogue»

The reliability of the Historical Italian Geomagnetic Data Catalogue, comprising 536 directions and 393 intensities, has been assessed by comparing the historical geomagnetic measurements with the GUFM1 model predictions. Such measurements were assessed at three selected relocation centres. For all the data contained in the Catalogue it has been calculated the discrepancy between the relocated data and the GUFM1-model prediction at the relocation centres. There is a correlation between relocation distance and the mean discrepancy. The upper limit of discrepancy assumable as relocation error has been selected using error distributions previously calculated using geomagnetic field models. Angular and intensity threshold lines have been slightly shifted upwards to account for the estimated error of GUFM1 model itself at the considered region, mainly due to the crustal field. The Italian database proved to contain reliable data, as only a very low percentage of data (namely 14 directions and 20 intensities) can be considered anomalous. Possible explanations for such questionable data are suggested. All the remaining data of this catalogue could thus be added to the databases used to produce regional or global geomagnetic models

Higgs Inflation as a Mirage

We discuss a simple unitarization of Higgs inflation that is genuinely weakly coupled up to Planckian energies. A large non-minimal coupling between the Higgs and the Ricci curvature is induced dynamically at intermediate energies, as a simple ratio of mass scales. Despite not being dominated by the Higgs field, inflationary dynamics simulates the `Higgs inflation' one would get by blind extrapolation of the low-energy effective Lagrangian, at least qualitatively. Hence, Higgs inflation arises as an approximate `mirage' picture of the true dynamics. We further speculate on the generality of this phenomenon and show that, if Higgs-inflation arises as an effective description, the details of the UV completion are necessary to extract robust quantitative predictions.Comment: 21 pages, 2 figure

Bayesian approach and Naturalness in MSSM analyses for the LHC

The start of LHC has motivated an effort to determine the relative probability of the different regions of the MSSM parameter space, taking into account the present, theoretical and experimental, wisdom about the model. Since the present experimental data are not powerful enough to select a small region of the MSSM parameter space, the choice of a judicious prior probability for the parameters becomes most relevant. Previous studies have proposed theoretical priors that incorporate some (conventional) measure of the fine-tuning, to penalize unnatural possibilities. However, we show that such penalization arises from the Bayesian analysis itself (with no ad hoc assumptions), upon the marginalization of the mu-parameter. Furthermore the resulting effective prior contains precisely the Barbieri-Giudice measure, which is very satisfactory. On the other hand we carry on a rigorous treatment of the Yukawa couplings, showing in particular that the usual practice of taking the Yukawas "as required", approximately corresponds to taking logarithmically flat priors in the Yukawa couplings. Finally, we use an efficient set of variables to scan the MSSM parameter space, trading in particular B by tan beta, giving the effective prior in the new parameters. Beside the numerical results, we give accurate analytic expressions for the effective priors in all cases. Whatever experimental information one may use in the future, it is to be weighted by the Bayesian factors worked out here.Comment: LaTeX, 19 pages, 3 figure

Bounds on the Higgs-Boson Mass in the Presence of Non-Standard Interactions

The triviality and vacuum stability bounds on the Higgs-boson mass are revisited in the presence of new interactions parameterized in a model-independent way by an effective lagrangian. When the scale of new physics is below 50 TeV the triviality bound is unchanged but the stability lower bound is increased by 40-60 GeV. Should the Higgs-boson mass be close to its current lower experimental limit, this leads to the possibility of new physics at the scale of a few TeV, even for modest values of the effective lagrangian parameters.Comment: 5 pages, 2 figures, RevTex, submitted to PR

Higgs-Boson Mass Limits and Precise Measurements beyond the Standard Model

The triviality and vacuum stability bounds on the Higgs-boson mass (\mh) were revisited in presence of weakly-coupled new interactions parameterized in a model-independent way by effective operators of dimension 6. The constraints from precision tests of the Standard Model were taken into account. It was shown that for the scale of new physics in the region \Lambda \simeq 2 \div 50 \tev the Standard Model triviality upper bound remains unmodified whereas it is natural to expect that the lower bound derived from the requirement of vacuum stability is substantially modified depending on the scale \La and strength of coefficients of effective operators. A natural generalization of the standard triviality condition leads also to a substantial reduction of the allowed region in the (\Lambda,\mh) space.Comment: 18 pages 3 eps figures. The discussion in the appendix was modified slightly and some typographical errors were correcte

Constraints on Supersymmetric Theories from μ→e,γ\mu\to e,\gamma

In the absence of any additional assumption it is natural to conjecture that sizeable flavour-mixing mass entries, $\Delta m^2$, may appear in the mass matrices of the scalars of the MSSM, i.e. $\Delta m^2\sim O(m^2)$. This flavour violation can still be reconciled with the experiment if the gaugino mass, $M_{1/2}$, is large enough, leading to a {\em gaugino dominance} framework (i.e. $M_{1/2}^2\gg m^2$), which permits a remarkably model--independent analysis. We study this possibility focussing our attention on the $\mu\rightarrow e,\gamma$ decay. In this way we obtain very strong and general constraints, in particular \frac{M_{1/2}^2}{\Delta m}\simgt 34\ {\rm TeV}. On the other hand, we show that our analysis and results remain valid for values of $m^2$ much larger than $\Delta m^2$, namely for \frac{\Delta m^2}{m^2}\simgt \frac{m^2} {10\ {\rm TeV^2}}, thus extending enormously their scope of application. Finally, we discuss the implications for superstring scenarios.Comment: 12 pages, Latex, 5 figures as uuencoded compressed postscript files, uses psfig.st

Cooper pair dispersion relation for weak to strong coupling

Cooper pairing in two dimensions is analyzed with a set of renormalized equations to determine its binding energy for any fermion number density and all coupling assuming a generic pairwise residual interfermion interaction. \ Also considered are Cooper pairs (CPs) with nonzero center-of-mass momentum (CMM)--usually neglected in BCS theory--and their binding energy is expanded analytically in powers of the CMM up to quadratic terms. A Fermi-sea-dependent {\it linear} term in the CMM dominates the pair excitation energy in weak coupling (also called the BCS regime) while the more familiar quadratic term prevails in strong coupling (the Bose regime). The crossover, though strictly unrelated to BCS theory {\it per se,} is studied numerically as it is expected to play a central role in a model of superconductivity as a Bose-Einstein condensation of CPs where the transition temperature vanishes for all dimensionality $d\leq 2$ for quadratic dispersion, but is {\it nonzero} for all $d\geq 1$ for linear dispersion.Comment: 11 pages plus 3 figures, revised version accepted in Physical Review

Postweaning growth and carcass traits in crossbred cattle from Hereford, Angus, Brangus, Beefmaster, Bonsmara, and Romosinuano maternal grandsires

The objective of this study was to characterize breeds representing diverse biological types for postweaning growth and carcass composition traits in terminal crossbred cattle. Postweaning growth and carcass traits were analyzed on 464 steers and 439 heifers obtained by mating F1 cows to Charolais and U.S. Meat Animal Research Center III (1/4 Hereford, 1/4 Angus, 1/4 Pinzgauer, and ¼ Red Poll) sires. The F1 cows were obtained from mating Angus and U.S. Meat Animal Research Center III dams to Hereford, Angus, Beefmaster, Brangus, Bonsmara, and Romosinuano sires. Traits evaluated were postweaning ADG, slaughter weight, HCW, dressing percentage, percentage of carcasses classified as USDA Choice, LM area, marbling score, USDA yield grade, fat thickness, retail product yield (percentage), and retail product weight. Maternal grandsire breed was significant (P \u3c 0.05) for all traits. Animals with Angus grandsires grew faster and had the heaviest carcasses, with the greatest percentage of carcasses classified as USDA Choice and the greatest marbling scores when compared with other grandsire breeds. Animals with Romosinuano and Bonsmara inheritance grew slower, had the lightest weights at slaughter, the lightest carcass weights, the least percentage of carcasses classified as USDA Choice, and the least amount of marbling and fat thickness. Animals with inheritance from these 2 breeds had a more desirable yield grade with the greatest retail product yield. Maternal granddam breed was significant (P \u3c 0.05) for marbling score, USDA yield grade, fat thickness, and retail product yield. Sex class was significant (P \u3c 0.05) for all traits except for retail product yield. Steers grew faster, were heavier, had heavier carcasses, and were leaner than heifers. Heifers had a greater dressing percentage, a greater percentage of carcasses classified as USDA Choice, a greater LM area, and a decreased yield grade when compared with steers. Sire and grandsire breed effects can be optimized by selection and use of appropriate crossbreeding systems

Analysis of optimal control problems of semilinear elliptic equations by BV-functions

Optimal control problems for semilinear elliptic equations with control costs in the space of bounded variations are analysed. BV-based optimal controls favor piecewise constant, and hence ’simple’ controls, with few jumps. Existence of optimal controls, necessary and sufficient optimality conditions of first and second order are analysed. Special attention is paid on the effect of the choice of the vector norm in the definition of the BV-seminorm for the optimal primal and adjoined variables.The first author was partially supported by Spanish Ministerio de Economía, Industria y Competitividad under research projects MTM2014-57531-P and MTM2017-83185-P. The second was partially supported by the ERC advanced grant 668998 (OCLOC) under the EUs H2020 research program