Relation between Tcc,bbT_{cc,bb} and Xc,bX_{c,b} from QCD

We have studied, using double ratio of QCD (spectral) sum rules, the ratio between the masses of $T_{cc}$ and X(3872) assuming that they are respectively described by the $D-{D}^*$ and $D-\bar{D}^*$ molecular currents. We found (within our approximation) that the masses of these two states are almost degenerate. Since the pion exchange interaction between these mesons is exactly the same, we conclude that if the observed X(3872) meson is a $D\bar{D}^*+c.c.$ molecule, then the $DD^*$ molecule should also exist with approximately the same mass. An extension of the analysis to the $b$-quark case leads to the same conclusion. We also study the SU(3) breakings for the $T^s_{QQ}/T_{QQ}$ mass ratios. Motivated by the recent Belle observation of two $Z_b$ states, we revise our determination of $X_b$ by combining results from exponential and FESR sum rules.Comment: revised version to appear on Phys. Lett.

On the Evaluation of the Mechanical Behaviour of Structural Glass Elements

Glass can be considered to be a high-technology engineering material with a multifunctional potential for structural applications. However, the conventional approach to the use of glass is often based only on its properties of transparency and isolation. It is thus highly appropriate and necessary to study the mechanical behaviour of this material and to develop adequate methods and models leading to its characterisation. It is evident that the great potential of growth for structural glass applications is an important opportunity of development for the glass industry and the building/construction sectors. The work presented in this paper is a reflection of this conclusion. The authors shortly present the state-of-the-art on the application of glass as a structural element in building and construction, and refer to other potential fields of application and available glass materials. The experimental procedures and methods adopted in three-point bending tests performed on 500 × 100 [mm2] float, laminated and tempered glass specimens with thicknesses between 4 and 19 mm are thoroughly described. The authors evaluated the mechanical strength and stiffness of glass for structural applications. This work contributes to a deeper knowledge of the properties of this material

Braneworlds scenarios in a gravity model with higher order spatial three-curvature terms

In this work we study a Horava-like five-dimensional model in the context of braneworld theory. To begin with, the equations of motion of such model are obtained and, within the realm of warped geometry, we show that the model is consistent if and only if $\lambda$ takes its relativistic value 1. Furthermore, since the first derivative of the warp factor is discontinuous over the branes, we show that the elimination of problematic terms involving the square of the warp factor second order derivatives are eliminated by imposing detailed balance condition in the bulk. Afterwards, the Israel's junction conditions are computed, allowing the attainment of an effective Lagrangian in the visible brane. In particular, for a (4+1)-dimensional Horava-like model defined in the bulk without cosmological constant, we show that the resultant effective Lagrangian in the brane corresponds to a (3+1)-dimensional Horava-like model with an emergent positive cosmological constant but without detailed balance condition. Now, restoration of detailed balance condition, at this time imposed over the brane, plays an interesting role by fitting accordingly the sign of the arbitrary constant $\beta$ that labels the extra terms in the model, insuring a positive brane tension and a real energy for the graviton within its dispersion relation. To end up with, the brane consistency equations are obtained and, as a result, we show that the detailed balance condition again plays an essential role in eliminating bad behaving terms and that the model admits positive brane tensions in the compactification scheme if, and only if, $\beta$ is negative, what is in accordance with the previous result obtained for the visible brane.Comment: 23 pages, 1 figure, title modifie

Consórcios com potencial de uso como adubo verde no município de Paty do Alferes-RJ.

Foi feito um experimento sob condições de campo no município de Paty do Alferes-RJ, com a finalidade de avaliar os efeitos dos consórcios, mucuna-preta (Mucuna aterrima) e crotalaria (Crotalaria juncea), consorciados com o milho (Zea mays cv. BR-116), na produção de fitomassa e acumulo de nitrogênio nas plantas dessas espécies e das plantas invasoras. O delineamento experimental foi O de blocos ao acaso, com quatro repetições e os três tratamentos: mucuna-preta + milho; crotalaria + milho e milho. A produção de fitomassa seca no tratamento só com milho foi significantemente (p<0,05) maior quando comparada com a produção do milho no consórcio, aproximadamente o dobro e nove vezes maior que nos consórcios com mucuna-preta e crotalaria respectivamente. No consórcio mucuna preta + milho, a leguminosa contribuiu com 61 % da produção da fitomassa seca, enquanto no consórcio crotalaria+ milho a contribuição foi de 89%. Não foi observado plantas invasoras nas parcelas do consorcio de mucuna-preta + milho. A fitomassa seca do milho nas parcelas sem consórcio apresentou um teor de N (0,69%) menor do que no milho consorciado com a crotalaria (1,36%) e com mucuna-preta (1,25%).0 teor de N da mucuna-preta (3,12%) no consórcio foi maior do que com a crotalaria (2,18%). A produção de N total do consórcio mucuna-preta + milho foi significantemente (p<0,05) maior 54 e 338% do que a do consórcio crotalaria + milho e do tratamento com milho, respectivamente, enquanto o tratamento crotalaria + milho superou o tratamento so com milho, em 185%. A produyao de N da mucuna-preta no consórcio foi 32% maior do que o da crotalaria. A mucuna-preta e a crotalaria no consórcio com o milho, num intervalo de 105 dias, do plantio até o corte, produziram cerca de 4,8 e 3,7 kg de N ha-1dia-1, respectivamente. Isto faz destas leguminosas um grande potencial para uso como adubo verde na região de Paty do Alferes-RJ. A field experiment was set up at the Municipality of Paty do Alferes, RJ, aiming the evaluation of intercropping the summer green manure velvet bean (Mucuna aterrima) and sunnhemp (Crotalaria juncea) with maize (Zea mays cv BR 116) on the biomass production and N accumulation in these species and in the weeds. The experimental design was in randomised blocks with four replications. The treatments were velvet bean + maize, sunnhemp + maize and maize. The dry mass production of the maize treatment was significantly higher (p<0.05) than maize intercropped with green manure. Maize only areas produced the double and nine-fold the dry mass accumulated by maize intercropped with velvet bean and sunnhemp, respectively. In the velvet bean maize intercrop the legume contributed to 61 % of total mass production while sunnhemp contributed to 89% of the total mass when intercropped with maize. There were no weeds in the plots with the intercrop of maize and velvet bean. The dry mass of maize in the pure maize plots had a N content (0.69%) lower than maize intercropped with sunnhemp (1.36%) and with velvet bean (1.25%). The N content in velvet bean (3.12%) was higher than that in sunnhemp (2.18%). The total N accumulated in the maize - velvet bean intercropping was 54% and 338% higher (p<0.05) than that accumulated in maize-sunnhemp intercropping and in pure maize crop, respectively, while the treatment maize-sunnhemp surpassed the pure maize treatment in 185%. The N production in velvet bean intercropped with maize was 32% higher than that in sunnhemp under the same condition. Velvet bean and sunnhemp intercropped with maize yielded respectively 4.8 and 3.7 kg N ha-1 day-1 during 105 days that comprised the planting-cut interval. This pointed out that these legumes have a strong potential to be used as green manure in the region of Paty do Alferes, RJ.Parceria: PESAGRO

Alterações morfológicas e qualidade fisiológica de sementes de mamão.

A análise de raios X é uma técnica importante na identificação de problemas associados à morfologia interna de sementes e ao seu potencial fisiológico. O objetivo do estudo foi avaliar os padrões morfológicos e a qualidade fisiológica de sementes de mamão obtidas de diferentes estádios de maturação e locais dentro do fruto com o auxílio das análises de raios X. Foram utilizadas sementes de mamão Formosa colhidos no estádio 1 de maturação. As sementes foram extraídas dos frutos nos estádios 1, 3, 5 e final. Os frutos foram armazenados em condições de laboratório (25 °C) e ao atingirem cada estádio de maturação, foram seccionados transversalmente em três partes de tamanhos iguais, sendo as sementes das duas extremidades (proximal e distal) extraídas separadamente daquelas localizadas na região central. Depois de lavadas e secas, as sementes foram utilizadas nas seguintes avaliações: 1) teste de germinação em papel germitest umedecido com água destilada em temperatura alternada 20-30°C. Avaliou-se a velocidade de germinação, plântulas normais na primeira contagem e as porcentagens de germinação, sementes dormentes e sementes inviáveis aos 30 dias; e, 2) teste de raios X, determinando-se as porcentagens de sementes cujo embrião era facilmente visível, com radícula visível e sementes aparentemente vazias. O experimento foi conduzido em delineamento inteiramente casualizado, em fatorial (duas regiões do fruto e quatro estádios de maturação) em quatro repetições. As médias comparadas pelo teste de Tukey a 5% de probabilidade. Constatou-se que sementes localizadas na parte central dos frutos apresentaram desempenho superior às sementes das extremidades. O estádio 1 de maturação apresentou número de sementes vazias e dormentes superior aos demais estádios. O teste de raios X favoreceu a diferenciação entre sementes de mamão vazias e com embrião completamente desenvolvido.Resum

X, Y and Z States

Many new states in the charmonium mass region were recently discovered by BaBar, Belle, CLEO-c, CDF, D0, BESIII, LHCb and CMS Collaborations. We use the QCD Sum Rule approach to study the possible structure of some of these states.Comment: Contribution for the proceedings of the "XII Quark Confinement and the Hadron Spectrum - CONF12" conferenc