Detection of Charged MSSM Higgs Bosons at CERN LEP-II and NLC

We study the possibility of detecting the charged Higgs bosons predicted in the Minimal Supersymmetric Standard Model $(H^\pm)$, with the reactions $e^{+}e^{-}\to \tau^-\bar \nu_{\tau}H^+, \tau^+\nu_\tau H^-$, using the helicity formalism. We analyze the region of parameter space $(m_{A^0}-\tan\beta)$ where $H^\pm$ could be detected in the limit when $\tan\beta$ is large. The numerical computation is done for the energie which is expected to be available at LEP-II ($\sqrt{s}=200$ GeV) and for a possible Next Linear $e^{+}e^{-}$ Collider ($\sqrt{s}=500$ GeV).Comment: Latex file and 5 figure

Multivariate Bayesian semiparametric models for authentication of food and beverages

Food and beverage authentication is the process by which foods or beverages are verified as complying with its label description, for example, verifying if the denomination of origin of an olive oil bottle is correct or if the variety of a certain bottle of wine matches its label description. The common way to deal with an authentication process is to measure a number of attributes on samples of food and then use these as input for a classification problem. Our motivation stems from data consisting of measurements of nine chemical compounds denominated Anthocyanins, obtained from samples of Chilean red wines of grape varieties Cabernet Sauvignon, Merlot and Carm\'{e}n\`{e}re. We consider a model-based approach to authentication through a semiparametric multivariate hierarchical linear mixed model for the mean responses, and covariance matrices that are specific to the classification categories. Specifically, we propose a model of the ANOVA-DDP type, which takes advantage of the fact that the available covariates are discrete in nature. The results suggest that the model performs well compared to other parametric alternatives. This is also corroborated by application to simulated data.Comment: Published in at http://dx.doi.org/10.1214/11-AOAS492 the Annals of Applied Statistics (http://www.imstat.org/aoas/) by the Institute of Mathematical Statistics (http://www.imstat.org

Threshold voltage and space charge in organic transistors

We investigate rubrene single-crystal field-effect transistors, whose stability and reproducibility are sufficient to measure systematically the shift in threshold voltage as a function of channel length and source-drain voltage. The shift is due to space-charge transferred from the contacts, and can be modeled quantitatively without free fitting parameters, using Poisson's equation, and by assuming that the density of states in rubrene is that of a conventional inorganic semiconductor. Our results demonstrate the consistency, at the quantitative level, of a variety of recent experiments on rubrene crystals, and show how the use of FET measurements can enable the determination of microscopic parameters (e.g., the effective mass of charge carriers).Comment: 4 pages, 4 figure