Littlest Higgs with T-parity: Status and Prospects

The Littlest Higgs model with T-parity is providing an attractive solution to the fine-tuning problem. This solution is only entirely natural if its intrinsic symmetry breaking scale f is relatively close to the electroweak scale. We examine the constraints using the latest results from the 8 TeV run at the LHC. Both direct searches and Higgs precision physics are taken into account. The constraints from Higgs couplings are by now competing with electroweak precision tests and both combined exclude f up to 694 GeV or 560 GeV depending on the implementation of the down-type Yukawa sector. Direct searches provide robust and complementary limits and constrain f to be larger than 638 GeV. We show that the Littlest Higgs model parameter space is slowly driven into the TeV range. Furthermore, we develop a strategy on how to optimise present supersymmetry searches for the considered model, with the goal to improve the constraints and yield more stringent limits on f.Comment: 43 pages, 16 figures, version 2 updated to JHEP 02 (2014) 05

Sharpening mT2m_{T2} cusps: the mass determination of semi-invisibly decaying particles from a resonance

We revisit mass determination techniques for the minimum symmetric event topology, namely $X$ pair production followed by $X \to \ell N$, where $X$ and $N$ are unknown particles with the masses to be measured, and $N$ is an invisible particle, concentrating on the case where $X$ is pair produced from a resonance. We consider separate scenarios, with different initial constraints on the invisible particle momenta, and present a systematic method to identify the kinematically allowed mass regions in the $(m_N, m_X)$ plane. These allowed regions exhibit a cusp structure at the true mass point, which is equivalent to the one observed in the $m_{T2}$ endpoints in certain cases. By considering the boundary of the allowed mass region we systematically define kinematical variables which can be used in measuring the unknown masses, and find a new expression for the $m_{T2}$ variable as well as its inverse. We explicitly apply our method to the case that $X$ is pair produced from a resonance, and as a case study, we consider the process $pp \to A \to \tilde \chi_1^+ \tilde \chi_1^-$, followed by $\tilde \chi_1^\pm \to \ell^{\pm} \, \tilde \nu_{\ell}$, in the Minimal Supersymmetric Standard Model and show that our method provides a precise measurement of the chargino and sneutrino masses, $m_X$ and $m_N$, at $14 \, \mathrm{TeV}$ LHC with $300 \, \mathrm{fb}^{-1}$ luminosity.Comment: 18 pages, 13 figures, version 2 updated to JHEP 06 (2014) 17

Cluster recognition in spatial-temporal sequences: the case of forest fires

Forest fire sequences can be modelled as a stochastic point process where events are characterized by their spatial locations and occurrence in time. Cluster analysis permits the detection of the space/time pattern distribution of forest fires. These analyses are useful to assist fire-managers in identifying risk areas, implementing preventive measures and conducting strategies for an efficient distribution of the firefighting resources. This paper aims to identify hot spots in forest fire sequences by means of the space-time scan statistics permutation model (STSSP) and a geographical information system (GIS) for data and results visualization. The scan statistical methodology uses a scanning window, which moves across space and time, detecting local excesses of events in specific areas over a certain period of time. Finally, the statistical significance of each cluster is evaluated through Monte Carlo hypothesis testing. The case study is the forest fires registered by the Forest Service in Canton Ticino (Switzerland) from 1969 to 2008. This dataset consists of geo-referenced single events including the location of the ignition points and additional information. The data were aggregated into three sub-periods (considering important preventive legal dispositions) and two main ignition-causes (lightning and anthropogenic causes). Results revealed that forest fire events in Ticino are mainly clustered in the southern region where most of the population is settled. Our analysis uncovered local hot spots arising from extemporaneous arson activities. Results regarding the naturally-caused fires (lightning fires) disclosed two clusters detected in the northern mountainous are

Simulation Study of Multi-wire front Contact Grids for Silicon Solar Cells

Abstract Multi-wire (MW) front-contact schemes represent a promising alternative to standard H-pattern structure with ribbon busbar (BB) in silicon solar cells. In the case of MW schemes, busbar are replaced by copper wires. MW have been demonstrated to enhance the photo-generation with respect to a standard H-pattern structure with ribbon busbar when solar cells are encapsulated and assembled in modules. However, the influence of the geometrical and optical properties of the encapsulation layers as well as of wires on the optical effective shading is not exhaustively treated by the literature. In this work, we have performed electro-optical simulations of MW and BB based solar cells in order to calculate the effective optical shading factor, the enhancement of conversion efficiency and the saving of contact-paste, with respect to the BB design. Specifically, we have studied by means of a ray-tracing simulation tool the significant impact of the front contact grid geometry, of the encapsulation layer thickness and of the optical properties of the cell front interface on the effective optical shading. The calculated values of effective optical shading are used to determine the enhancement of the figures of merit and the paste saving with respect to the reference silver BB scheme. On the basis of our calculations the adoption of optimized MW designs may enhance the conversion efficiency up to 0.5% abs , allowing paste saving up to 50 mg per cell

A Comparative Study of MWT Architectures by Means of Numerical Simulations

AbstractIn order to improve the efficiency of c-Si and mc-Si solar cells, Metal Wrap Though (MWT) architecture is investigated. In this paper we implement TCAD numerical simulations to analyze the performance of MWT cells with a point busbar or a continuous busbar at the back side. The two topologies of MWT cells are compared in both illuminated and dark conditions, aiming at understanding and comparing the resistive and recombination losses. The impact of the separation region is also studied, highlighting the degradation effect on the Fill Factor (FF) and on the efficiency in the two structures. We observe that the separation region dimension leads to a higher degradation of efficiency in case of continuous busbar

Prenatal Exposure to BPA: The Effects on Hepatic Lipid Metabolism in Male and Female Rat Fetuses

Bisphenol A (BPA) is an organic chemical compound widely used for manufacturing plastics. BPA exposure originates principally from the diet, but it can also originate from dermal contact. In over 90% of individuals, including pregnant women, BPA is detectable in several body fluids. The effects of this exposure on the fetus are under active investigation in several research laboratories. The aim of our work was to study the impact of prenatal exposure to BPA in the liver of rat fetuses from a sex-dependent point of view. We particularly investigated the effects of prenatal BPA exposure on hepatic lipids because of their crucial role, not only for the liver, but also for the whole-body functions. Our results demonstrate that the liver of rat fetuses, in utero exposed to a very low dose of BPA (2.5 µg/kg/day), displays significant modulations with regard to proteins involved in cholesterol and fatty acid biosynthesis and trafficking. Moreover, an impact on inflammatory process has been observed. All these effects are dependent on sex, being observable only in female rat fetuses. In conclusion, this work demonstrates that maternal exposure to BPA compromises hepatic lipid metabolism in female offspring, and it also reveals the perspective impact of BPA on human health at doses currently considered safe

Biological and clinical effects of abiraterone on anti-resorptive and anabolic activity in bone microenvironment

Abiraterone acetate (ABI) is associated not only with a significant survival advantage in both chemotherapy-naive and -treated patients with metastatic castration-resistant prostate cancer (mCRPC), but also with a delay in time to development of Skeletal Related Events and in radiological skeletal progression. These bone benefits may be related to a direct effect on prostate cancer cells in bone or to a specific mechanism directed to bone microenvironment. To test this hypothesis we designed an in vitro study aimed to evaluate a potential direct effect of ABI on human primary osteoclasts/osteoblasts (OCLs/OBLs). We also assessed changes in bone turnover markers, serum carboxy-terminal collagen crosslinks (CTX) and alkaline phosphatase (ALP), in 49 mCRPC patients treated with ABI.Our results showed that non-cytotoxic doses of ABI have a statistically significant inhibitory effect on OCL differentiation and activity inducing a down-modulation of OCL marker genes TRAP, cathepsin K and metalloproteinase-9. Furthermore ABI promoted OBL differentiation and bone matrix deposition up-regulating OBL specific genes, ALP and osteocalcin. Finally, we observed a significant decrease of serum CTX values and an increase of ALP in ABI-treated patients.These findings suggest a novel biological mechanism of action of ABI consisting in a direct bone anabolic and anti-resorptive activity

Liver abscess caused by Actinomyces odontolyticus: a difficulty diagnostic - case report/ Abcesso hepático causado por Actinomyces odontolyticus: um diagnóstico de dificuldade - relato de caso

Actinomyces odontolyticus are slow-growing, facultative anaerobic, gram-positive bacilli and rarely cause liver abscesses. We present a black male, aged 47, with adynamia, jaundice, weight loss, abdominal pain and fever, which started 6 months prior, who was diagnosed with liver abscess and underwent percutaneous drainage, with delayed identification of the pathogen in culture, after three weeks with growth of A. odontolyticus. The literature shows low positivity (10%) in the culture due to its slow growth and technical difficulties; usually positive about two weeks. This is important to alert physicians of the diagnostic possibility and the difficulty of managing it until identification