Exploring B_{d,s}-> KK decays through flavour symmetries and QCD-factorisation

We present a new analysis of B_{d,s}->KK modes within the SM, relating them in a controlled way through SU(3)-flavour symmetry and QCD-improved factorisation. We propose a set of sum rules for B_{d,s}-> K^0{\bar K}^0 observables. We determine B_s-> KK branching ratios and CP-asymmetries as functions of A_{dir}(B_d-> K^0{\bar K}^0), pointing out a conflict between BR(B_s-> K+K-) in the SM and data. Finally, we predict the amount of U-spin breaking between B_d-> pi+pi- and B_s-> K+K-.Comment: 4 pages, 2 figures. Enlarged discussion on 1/mb contribution

Phenomenology of an SU(2)×SU(2)×U(1)SU(2) \times SU(2) \times U(1) model with lepton-flavour non-universality

We investigate a gauge extension of the Standard Model in light of the observed hints of lepton universality violation in $b \to c \ell \nu$ and $b \to s \ell^+ \ell^-$ decays at BaBar, Belle and LHCb. The model consists of an extended gauge group $\mathrm{SU(2)}_{1} \times \mathrm{SU(2)}_{2} \times \mathrm{U(1)}_Y$ which breaks spontaneously around the TeV scale to the electroweak gauge group. Fermion mixing effects with vector-like fermions give rise to potentially large new physics contributions in flavour transitions mediated by $W^{\prime}$ and $Z^{\prime}$ bosons. This model can ease tensions in $B$-physics data while satisfying stringent bounds from flavour physics, tau decays, and electroweak precision data. Possible ways to test the proposed new physics scenario with upcoming experimental measurements are discussed. Among other predictions, the lepton flavour violating ratios $R_M$, with $M = K^*, \phi$, are found to be reduced with respect to the Standard Model expectation $R_M \simeq 1$.Comment: 46 pages, 11 figures. v2: version published in JHE

Non-abelian gauge extensions for B-decay anomalies

We study the generic features of minimal gauge extensions of the Standard Model in view of recent hints of lepton-flavor non-universality in semi-leptonic $b \to s \ell^+ \ell^-$ and $b \to c \ell \nu$ decays. We classify the possible models according to the symmetry-breaking pattern and the source of flavor non-universality. We find that in viable models the $\mathrm{SU(2)}_L$ factor is embedded non-trivially in the extended gauge group, and that gauge couplings should be universal, hinting to the presence of new degrees of freedom sourcing non-universality. Finally, we provide an explicit model that can explain the $B$-decay anomalies in a coherent way and confront it with the relevant phenomenological constraints.Comment: 8 pages, 2 figures; discussion improved, a figure and references added; conclusions unchange

Top mass dependent alpha_s^3 corrections to B-meson mixing in the MSSM

We compute the top mass dependent NLO strong interaction matching conditions to the Delta F=2 effective Hamiltonian in the general MSSM. We study the relevance of such corrections, comparing its size with that of previously known NLO corrections in the limit mt->0, in scenarios with degeneracy, alignment, and hierarchical squarks. We find that, while these corrections are generally small, there are regions in the parameter space where the contributions to the Wilson coefficients C1 and C4 could partially overcome the expected suppression m_t/M_SUSY.Comment: 15 pages, 6 figure

Updated NNLO QCD predictions for the weak radiative B-meson decays

Weak radiative decays of the B mesons belong to the most important flavor changing processes that provide constraints on physics at the TeV scale. In the derivation of such constraints, accurate standard model predictions for the inclusive branching ratios play a crucial role. In the current Letter we present an update of these predictions, incorporating all our results for the O(alpha_s^2) and lower-order perturbative corrections that have been calculated after 2006. New estimates of nonperturbative effects are taken into account, too. For the CP- and isospin-averaged branching ratios, we find B_{s gamma} = (3.36 +_ 0.23) * 10^-4 and B_{d gamma} = 1.73^{+0.12}_{-0.22} * 10^-5, for E_gamma > 1.6GeV. Both results remain in agreement with the current experimental averages. Normalizing their sum to the inclusive semileptonic branching ratio, we obtain R_gamma = ( B_{s gamma} + B_{d gamma})/B_{c l nu} = (3.31 +_ 0.22) * 10^-3. A new bound from B_{s gamma} on the charged Higgs boson mass in the two-Higgs-doublet-model II reads M_{H^+} > 480 GeV at 95%C.L.Comment: journal version, 5 pages, no figure

Soil Quality Assessment after 25 Years of Sewage Sludge vs. Mineral Fertilization in a Calcareous Soil

The aim of this work was to identify the most sensitive soil quality indicators and assess soil quality after long-term application of sewage sludge (SS) and conventional mineral fertilization for rainfed cereal production in a sub-humid Mediterranean calcareous soil. The treatments included six combinations of SS at different doses (40 t ha−1 and 80 ha−1) and frequencies (every 1, 2 and 4 years), plus a control with mineral fertilization, and a baseline control without fertilization. Twenty-five years after the onset of the experiment, 37 pre-selected physical, chemical and biological soil parameters were measured, and a minimum data set was determined. Among these indicators, those significantly affected by treatment and depth were selected as sensitive. A principal component analysis (PCA) was then performed for each studied depth. At 0–15 cm, PCA identified three factors (F1, F2 and F3), and at 15–30 cm, two factors (F4 and F5) that explained 71.5% and 67.4% of the variation, respectively, in the soil parameters. The most sensitive indicators (those with the highest correlation within each factor) were related to nutrients (P and N), organic matter, and trace metals (F1 and F4), microporosity (F2), earthworm activity (F3), and exchangeable cations (F5). Only F3 correlated significantly (and negatively) with yield. From these results, we concluded that soil quality can be affected in opposite directions by SS application, and that a holistic approach is needed to better assess soil functioning under SS fertilization in this type of agrosystem.This project has received funding from the National Institute for Agricultural and Food Research and Technology (INIA) through the RTA2017-00088-C03-01 project and from the European Union’s H2020 research and innovation programme under Marie Sklodowska-Curie grant agreement No. 80158

Development of new remediation technologies for contaminated soils based on the application of zero-valent iron nanoparticles and bioremediation with compost

This study aimed to develop new techniques for the remediation of contaminated soils based on the applicationof zero-valent iron nanoparticles (nZVI) and bioremediation with compost from organic wastesand a mixed technique of both. An assessment of the effectiveness of remediation in two soils contaminatedwith hydrocarbons and heavy metals was carried out, with the aim of looking for positive synergiesby combining the two techniques, and demonstrating their viability on an industrial scale. The applicationof nZVI for in situ immobilization of As and Cr in two different soils (Soil I from a contaminatedindustrial site and Soil II, contaminated artificially) showed a decrease in the concentration of As in SoilI and Soil II, as well as a decrease in Cr concentration for Soil I and Soil II in the leachate of both soils.The addition of compost and nanoparticles under uncontrolled environmental conditions in biopiles wasable to produce a decrease in the concentration of aliphatic hydrocarbons of up to 60% in the two soils.Especially, degradation and transformation of longer chains occurred. A significant reduction of ecotoxicitywas observed throughout the process in the biopile of soil II, not reaching the LC50 even with 100%of the sample after the treatment, in both earthworm and seeds growth tests

Identification by means of molecular tools of the microbiota responsible for the formation of histamine accumulated in commercial cheeses in Spain

Histamine intoxication is an important food safety and public health concern. Ripened cheeses are the most common dairy products in which histamine can accumulate. Histamine is formed by the microbiota present in cheese by decarboxylation of histidine, due to the action of the histidine decarboxylase. This study's objective was to identify the responsible for the formation of histamine accumulated in commercial cheeses. The content of histamine of 39 different types of cheeses marketed in Spain, of varying milk origin, was assessed. About one third of the cheeses analysed contained more than 200 mg/kg histamine; two cheeses exceeded 500 mg/kg histamine, the consumption of such cheeses can be harmful or even toxic for consumers. The five cheeses with the highest histamine concentrations were selected for in-depth molecular analysis. Firstly, bacterial and yeast isolates were obtained, and then the total genetic material from the cheeses was analysed, in order to verify the putative presence of the hdc histidine decarboxylase gene. In order to identify the histamine producing microorganisms, the nucleotide sequences of the histidine decarboxylase genes from the cheeses were amplified, and subjected them to Sanger sequencing. In four of the five selected cheeses, the main histamine producer was identified as Lentilactobacillus parabuchneri, whereas in the remaining cheese it was Tetragenococcus halophilus. The hdc gene was located in an unstable plasmid, only present in that cheese sample. Since all histamine producing microorganisms identified in this study are not part of the species used in cheese starter cultures, an improvement of hygienic manufacturing practices and/or thermal treatments for microbial inactivation in milk may be considered to prevent histamine accumulation in cheeses during ripening

Bd^0(t)->pi^+pi^- and Bs^0(t)-> K^+ K^- Decays: A Tool to Measure New-Physics Parameters

If physics beyond the standard model is present in B decays, experimental measurements seem to suggest that it principally affects those processes with significant b->s penguin amplitudes. It was recently argued that, in general, such new-physics (NP) effects can be parametrized in terms of a single NP amplitude A^q and phase \Phi_q, for q=u,d,s,c. In this paper, we show that the study of the decays Bs(t) -> K^+ K^- and Bd(t) -> \pi^+\pi^- allows one to measure the NP parameters A^u and \Phi_u. We examine the implications for this method of the latest experimental results on these decays. If NP is found in Bs(t) -> K^+ K^-, it can be partially identified through measurements of Bs(t)-> K^0 \bar K^0.Comment: 12 pages, 2 figures, LaTeX. Changed reference