How sensitive to FCNC can B0B^0 CP asymmetries be?

We show that the study of CP asymmetries in neutral B-meson decays provides a very sensitive probe of flavour-changing neutral currents (FCNC). We introduce two new angles, $\alpha_{SM}$ and $\beta_{SM}$, whose main feature is that they can be readily obtained from the measurement of the CP asymmetries $a_{J/\psi K_s}$, $a_{\pi^+ \pi^-}$ and the ratio $R_u \equiv|V_{ud}V_{ub}^*|/|V_{cd}V_{cb}^*|$, providing a quantitative test of the presence of new physics in a model-independent way. Assuming that new physics is due to the presence of an isosinglet down-type quark, we indicate how to reconstruct the unitarity quadrangles and point out that the measurements of the above asymmetries, within the expected experimental errors, may detect FCNC effects, even for values of $|\sum_{i=1}^3 V_{id} V_{ib}^* / (V_{td} V_{tb}^*)|$ at the level of a few times $10^{-2}$.Comment: 19 pages including 9 figure

Pesca artesanal do camarão sete-barbas: uma caracterização sócio-econômica na Penha, SC

Marine resources exploration along Santa Catarina coast plays an important role in the socioeconomic and cultural context. Considering this information, the elaboration of a management plan for fishery resources should consider beyond the biological, physical and chemical components, the socioeconomic dimension. This work aimed to characterize the socioeconomic profile of the fishermen of sea-bob-shrimp at Penha (Santa Catarina State). To accomplish this characterization, 55 local fishermen were interviewed, regarding scholar instruction of fisherman and their family, data on fishery activity, destination and commercialization of the shrimp and by-catch, and also the gear utilized in the fishery. Results showed an age composition of fishermen predominantly among 40 and 50 years old, confirming that the activity is performed mainly by the elders of the community, which on the other hand, cannot keep their family only with the fishery profits. Such situation is driving the activity to a decline, in a way that fishermen are being obligated to accept informal jobs, putting in risk their survivorship and a rich Azorean culture.Marine resources exploration along Santa Catarina coast plays an important role in the socioeconomic and cultural context. Considering this information, the elaboration of a management plan for fishery resources should consider beyond the biological, physical and chemical components, the socioeconomic dimension. This work aimed to characterize the socioeconomic profile of the fishermen of sea-bob-shrimp at Penha (Santa Catarina State). To accomplish this characterization, 55 local fishermen were interviewed, regarding scholar instruction of fisherman and their family, data on fishery activity, destination and commercialization of the shrimp and by-catch, and also the gear utilized in the fishery. Results showed an age composition of fishermen predominantly among 40 and 50 years old, confirming that the activity is performed mainly by the elders of the community, which on the other hand, cannot keep their family only with the fishery profits. Such situation is driving the activity to a decline, in a way that fishermen are being obligated to accept informal jobs, putting in risk their survivorship and a rich Azorean culture

Analysis of a model with a common source of CP violation

We work in a model where all CP violating phenomena have a common source. CP is spontaneously broken at a large scale $V$ through the phase of a complex singlet scalar. An additional $SU(2)_L$ singlet vector-like down-type quark relates this high scale CP violation to low energy. We quantitatively analyze this model in the quark sector. We obtain the numerical values of the parameters of the Lagrangian in the quark sector for a specific ansatz of the $4\times4$ down-type quark mass matrix where the weak phase is generated minimally. $Z \bar b b$ vertex will modify in presence of the extra vector-like down-type quark. From the experimental lower bound of the partial decay width $Z\to \bar b b$ we find out the lower bound of the additional down-type quark mass. Tree level flavor changing neutral current appears in this model due to the presence of the extra vector-like down-type quark. We give the range of values of the mass splitting $\Delta m_{B_q}$ in $B^0_q-{\bar B}^0_q$ system using SM box, $Z$ mediating tree level and $Z$ mediating one loop diagrams together for both $q=d, s$. We find out the analytical expression for $\Gamma_{12}^q$ in this model from standard box, $Z$ and Higgs mediated penguin diagrams for $B^0_q-{\bar B}^0_q$ system, $q=d,s$. From this we numerically evaluate the decay width difference $|\Delta\Gamma_{B_q}/\Gamma_{B_q}|$. We also find out the numerical values of the CP asymmetry parameters $a_J$ and $a_\pi$ for the decays $B^0_d\to J/\psi K_s$ and $B^0_d\to \pi^+ \pi^-$ respectively. We get the lower bound of the scale $V$ through the upper bound of the strong CP phase.Comment: 20 pages, no figures New materials and references have been added. Text has been modified. To be appear in J.Phys.

Large Neutrino Mixing with Universal Strength of Yukawa Couplings

We analyse, within the framework of universal strength for Yukawa couplings (USY), various structures for the Dirac and Majorana neutrino mass matrices giving rise, through the see-saw mechanism, to a degenerate mass spectrum. A specific USY ansatz is presented for the charged lepton and neutrino effective mass matrix, leading to quasi-degenerate neutrinos and a leptonic mixing matrix which provides a large angle solution for both the atmospheric and solar neutrino problems.Comment: 7 pages, ReVTeX, small comments adde

Correlations of the elements of the neutrino mass matrix

Assuming Majorana nature of neutrinos, we re-investigate, in the light of the recent measurement of the reactor mixing angle, the allowed ranges for the absolute values of the elements of the neutrino mass matrix in the basis where the charged-lepton mass matrix is diagonal. Apart from the derivation of upper and lower bounds on the values of the matrix elements, we also study their correlations. Moreover, we analyse the sensitivity of bounds and correlations to the global fit results of the neutrino oscillation parameters which are available in the literature.Comment: 37 pages, 146 figures, minor corrections, 17 additional figures, version for publication in JHE

Tree-level FCNC in the B system: from CP asymmetries to rare decays

Tree-level Flavor-Changing Neutral Currents (FCNC) are characteristic of models with extra vector-like quarks. These new couplings can strongly modify the B^0 CP asymmetries without conflicting with low--energy constraints. In the light of a low CP asymmetry in B --> J/\psi K_{S}, we discuss the implications of these contributions. We find that even these low values can be easily accommodated in these models. Furthermore, we show that the new data from B factories tend to favor an O(20) enhancement of the b --> d l \bar{l} transition over the SM expectation.Comment: 5 pages, 4 figures. Accepted version in PRD. Updated analysis with the new results from BaBar and BELLE. Figures enlarged, small typos corrected. Conclusions essentially unchange

Produção de matéria seca em área de caronal (Elyonurus muticus), no pantanal Sul-Mato-Grossense.

O trabalho objetivou avaliar a producao total de uma area de pastagem nativa, com queima anual e bienal, com e sem pastejo, atraves de exclusoes, no periodo de agosto97 a julho99. O delineamento experimental foi o de blocos complementares casualizados, com quatro tratamentos e tres repeticoes. A analise de variancia da producao total mostrou que nao houve diferenca estatistica entre os tratamentos. A especie Elyonurus musticus foi efetada pelos tratamentos. [Dry matter production in caronal grass (Eyonurus muticus) Area, south Pantanal]. Abstract: This study aimed to evaluate the total production of a caronal grass area, with annual and biennial burnings, and grazed and ungrazed fields, through exclusions, in the period of August/97 to july/99. The experimental design was a randomized complete block with four treatments and three replications. The results of the analysis of variance on total production showed that there were no differences among treatments. The plant species ?Elyonurus muticus? was affected by the treatments

Abelian symmetries in multi-Higgs-doublet models

N-Higgs doublet models (NHDM) are a popular framework to construct electroweak symmetry breaking mechanisms beyond the Standard model. Usually, one builds an NHDM scalar sector which is invariant under a certain symmetry group. Although several such groups have been used, no general analysis of symmetries possible in the NHDM scalar sector exists. Here, we make the first step towards this goal by classifying the elementary building blocks, namely the abelian symmetry groups, with a special emphasis on finite groups. We describe a strategy that identifies all abelian groups which are realizable as symmetry groups of the NHDM Higgs potential. We consider both the groups of Higgs-family transformations only and the groups which also contain generalized CP transformations. We illustrate this strategy with the examples of 3HDM and 4HDM and prove several statements for arbitrary N.Comment: 33 pages, 2 figures; v2: conjecture 3 is proved and becomes theorem 3, more explanations of the main strategy are added, matches the published versio

Dietary nitrate increases arginine availability and protects mitochondrial complex I and energetics in the hypoxic rat heart

This is the final version. It was first published by Wiley in The Journal of Physiology at http://onlinelibrary.wiley.com/doi/10.1113/jphysiol.2014.275263/abstract.Hypoxic exposure is associated with impaired cardiac energetics in humans and altered mitochondrial function, with suppressed complex I-supported respiration, in rat heart. This response might limit reactive oxygen species (ROS) generation, but at the cost of impaired electron transport chain (ETC) activity. Dietary nitrate supplementation improves mitochondrial efficiency and can promote tissue oxygenation by enhancing blood flow. We therefore hypothesised that ETC dysfunction, impaired energetics and oxidative damage in the hearts of rats exposed to chronic hypoxia could be alleviated by sustained administration of a moderate dose of dietary nitrate. Male Wistar rats (n=40) were given water supplemented with 0.7 mmol/L NaCl (as control) or 0.7 mmol/L NaNO3, elevating plasma nitrate levels by 80%, and were exposed to 13% O2 (hypoxia) or normoxia (n=10 per group) for 14 days. Respiration rates, ETC protein levels, mitochondrial density, ATP content and protein carbonylation were measured in cardiac muscle. Complex I respiration rates and protein levels were 33% lower in hypoxic/NaCl rats compared with normoxic/NaCl controls. Protein carbonylation was 65% higher in hearts of hypoxic rats compared with controls, indicating increased oxidative stress, whilst ATP levels were 62% lower. Respiration rates, complex I protein and activity, protein carbonylation and ATP levels were all fully protected in the hearts of nitrate-supplemented hypoxic rats. Both in normoxia and hypoxia, dietary nitrate suppressed cardiac arginase expression and activity and markedly elevated cardiac L-arginine concentrations, unmasking a novel mechanism of action by which nitrate enhances tissue NO bioavailability. Dietary nitrate therefore alleviates metabolic abnormalities in the hypoxic heart, improving myocardial energetics