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

Chiral Symmetry and light resonances in hot and dense matter

We present a study of the $\pi\pi$ scattering amplitude in the $\sigma$ and $\rho$ channels at finite temperature and nuclear density within a chiral unitary framework. Meson resonances are dynamically generated in our approach, which allows us to analyze the behavior of their associated scattering poles when the system is driven towards chiral symmetry restoration. Medium effects are incorporated in three ways: (a) by thermal corrections of the unitarized scattering amplitudes, (b) by finite nuclear density effects associated to a renormalization of the pion decay constant, and complementarily (c) by extending our calculation of the scalar-isoscalar channel to account for finite nuclear density and temperature effects in a microscopic many-body implementation of pion dynamics. Our results are discussed in connection with several phenomenological aspects relevant for nuclear matter and Heavy-Ion Collision experiments, such as $\rho$ mass scaling vs broadening from dilepton spectra and chiral restoration signals in the $\sigma$ channel. We also elaborate on the molecular nature of $\pi\pi$ resonances.Comment: 14 pages, 14 figures. Contribution to Hard Probes 2008, Illa de A Toxa, Spain, June 8th-14th 200

Comparative analysis of minor bioactive constituents (CoQ10, tocopherols and phenolic compounds) in Arbequina extra virgin olive oils from Brazil and Spain

There is currently an emerging production of olive oil in Brazil but it is still poorly characterized. In this study, we performed a comparative analysis of minor bioactive constituents (CoQ 10 tocopherols and phenolic compounds) in extra virgin olive oil from different regions of Brazil and Spain, of Arbequina cultivar. Significant variations (P < 0.05) in the concentration of the compounds analyzed were observed among oils from the different growing areas, not only between Spanish and Brazilian samples but also within zones of the same country. All the oils analyzed showed a high content of CoQ 10 , which ranged from 48 to 85 mg/L. The α − tocopherol was the major isomer quantified and three main groups of phenolic compounds were identified: flavonoids (apigenin, luteolin), phenolic acids (naringenin, p-coumaric acid, vanillic acid) and phenolic alcohols (hydroxytyrosol). Climatic and geographic factors of the production zones greatly influenced the minor fraction composition; positive relationships between altitude and the level of CoQ 10 , tocopherols and phenolic compounds of the oils were observed, whereas a negative correlation with rainfalls was found. Chemometric analyses demonstrated that oils were differentiated by the chemical composition and origin area and that polyphenols (particularly hydroxytyrosol) held the major weight in the oil classification.We are grateful to the CAPES Foundation, (Ministry of Education) Brazil, for scholarship support provided to the first author. LCL is supported by the “Ramón y Cajal” National Programme (RYC-2011- 07643) and the grants SAF2013-47761-R and SAF2015-65786-R, Ministerio de Economía y Competitividad, Spain, and the European Regional Development Fund (ERDF). This work is part of the doctoral thesis of Thays Helena Borges, Ph.D. student from the Official Doctoral Program “Nutrition and Food Sciences” of the Granada University. The authors also would like to thank Consejo Regulador de Denominación de Origen (DOP) Estepa and DOP Les Garrigues; Casas Hualdo, Castillo Canena, Cortijo de Jara, Quaryat Dilar and Olivas do Sul for the donation of samples. We would like to dedicate to the memory of Carmen Cabrera-Vique.info:eu-repo/semantics/publishedVersio

His-Bundle Pacing in a Patient With Tricuspid and Mitral Prosthetic Valves Without Suitable Coronary Veins for Lead Placement

Atrioventricular block in patients with a prosthetic tricuspid valve and a pacemaker with a dysfunctional epicardial lead is not uncommon. In such instances, coronary sinus lead placement is the preferred option, but it has a failure rate of 10%-15%. An atrial transseptal left ventricular lead placement has been proposed as an alternative, but this approach is not feasible in patients with a prosthetic mitral valve. This analysis represents the first reported case of His-bundle pacing from the atria in a patient with prosthetic tricuspid and mitral valves, with no suitable coronary veins for lead placement. © 2021 The Author

Chiral dynamics of p-wave in K^- p and coupled states

We perform an evaluation of the p-wave amplitudes of meson-baryon scattering in the strangeness S=-1 sector starting from the lowest order chiral Lagrangians and introducing explicitly the Sigma^* field with couplings to the meson-baryon states obtained using SU(6) symmetry. The N/D method of unitarization is used, equivalent, in practice, to the use of the Bethe-Salpeter equation with a cut-off. The procedure leaves no freedom for the p-waves once the s-waves are fixed and thus one obtains genuine predictions for the p-wave scattering amplitudes, which are in good agreement with experimental results for differential cross sections, as well as for the width and partial decay widths of the Sigma^*(1385).Comment: LaTeX, 18 pages, 6 figure