Constraining the MSSM with universal gaugino masses and implication for searches at the LHC

Using a Markov chain Monte Carlo approach, we find the allowed parameter space of a MSSM model with seven free parameters. In this model universality conditions at the GUT scale are imposed on the gaugino sector. We require in particular that the relic density of dark matter saturates the value extracted from cosmological measurements assuming a standard cosmological scenario. We characterize the parameter space of the model that satisfies experimental constraints and illustrate the complementarity of the LHC searches, B-physics observables and direct dark matter searches for further probing the parameter space of the model. We also explore the different decay chains expected for the coloured particles that would be produced at LHC.Comment: 29 pages, 11 figure

The e+e- -> Z gamma gamma -> q q gamma gamma Reaction at LEP and Constraints on Anomalous Quartic Gauge Boson Couplings

The cross section of the process e^+ e^- -> Z \gamma\gamma -> qq \gamma \gamma is measured with 215 pb^-1 of data collected with the L3 detector during the final LEP run at centre-of-mass energies around 205 GeV and 207 GeV. No deviation from the Standard Model expectation is observed. The full data sample of 713 pb^-1, collected above the Z resonance, is used to constrain the coefficients of anomalous quartic gauge boson couplings to: -0.02 GeV^-2 < a_0/\Lambda^2 < 0.03 GeV^-2 and -0.07 GeV^-2 < a_c/\Lambda^2 < 0.05 GeV^-2, at 95% confidence level

Study of the e+e- -> Z gamma gamma -> q q~ gamma gamma Process at LEP

The process e^+e^- -> Z gamma gamma -> q q~ gamma gamma is studied in 0.5 fb-1 of data collected with the L3 detector at centre-of-mass energies between 130.1 GeV and 201.7 GeV. Cross sections are measured and found to be consistent with the Standard Model expectations. The study of the least energetic photon constrains the quartic gauge boson couplings to -0.008 GeV-2 < a_0/\Lambda^2 < 0.005 GeV-2 and -0.007 GeV-2 < a_c/\Lambda^2 < 0.011 GeV-2, at 95% confidence level

Study of the W+W-gamma Process and Limits on Anomalous Quartic Gauge Boson Couplings at LEP

The process e+e- -> W+ W- gamma is studied using the data collected by the L3 detector at LEP. New results, corresponding to an integrated luminosity of 427.4 pb-1 at centre-of-mass energies from 192 GeV to 207 GeV, are presented. The W+W- gamma cross sections are measured to be in agreement with Standard Model expectations. No hints of anomalous quartic gauge boson couplings are observed. Limits at 95% confidence level are derived using also the process e+e- --> nu nubar gamma gamma

Mechanisms and means of detection of biocontrol activity of Pseudozyma yeasts against plant-pathogenic fungi

Fungi belonging to Pseudozyma spp. represent a small group of yeasts that have drawn limited interest in the scientific literature. However, new research with one species of Pseudozyma, Pseudozyma flocculosa, has demonstrated the potential of this yeast as a biocontrol agent of plant-pathogenic fungi. Based on recent work, it appears that P. flocculosa, a natural inhabitant of the phyllosphere, possesses unique means of defending its ecological niche by producing unusual extracellular fatty acids that are detrimental to, among other fungi, powdery mildews, an important group of plant pathogens. Results from these studies have shown that the fatty acids naturally insert themselves into powdery mildew fungi and cause disorganization of cellular membranes and cell disintegration. Further work with insertional mutagenesis yielded mutants of P. flocculosa that represent valuable biological tools to better understand the properties of the yeast. For instance, preliminary work with mutants having lost their antagonistic properties has led to the isolation of a new metabolite with antifungal activity. Discoveries pertaining to the ecology and mode of action of P. flocculosa may lead to the study of unique metabolic or biological processes in other Pseudozyma spp. that could well release the untapped potential of these misunderstood yeasts