Stéphanie Cassel

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We consider current precision electroweak data, Z ′ searches and dark matter constraints and analyse their implications for an extension of the SM that includes an extra U(1) massive gauge boson and a particular hidden sector (“hidden valley”) with a confining (QCD-like) gauge group. The constraints on the Z ′ with arbitrary Z − Z ′ kinetic mixing coming(More)
A liquid chromatographic method has been developed for the analysis of polyglycerol fatty esters and fatty ethers which are non-ionic surfactants. Two methods were compared using either octadecyl silica or porous graphitic carbon. The octadecyl silica system with a hydroorganic mobile phase enables to compare the hydrophobic behavior of the compounds. The(More)
The interaction between the aphid Rhopalosiphum padi (L.) and the leafhopper Psammotettix alienus was investigated in the laboratory. The leafhoppers, when physically separated from aphid but with a common air supply, caused a reduction in aphid offspring production. One of the hypotheses to explain this result is that volatile compounds might be(More)
One of the most important solvent physical parameters for aggregation is the cohesive energy density (CED), for it gives an idea of the structured state of the solvent. Nevertheless, our studies on the behavior of catanionic amphiphiles in nonaqueous solvents demonstrated that in order to obtain objects the dielectric constant of the solvent was also a(More)
The Sommerfeld factor for arbitrary partial wave processes is derived in the non-relativistic limit. The s-wave and p-wave numerical results are presented for the case of Yukawa interactions. An approximate analytic expression is also found for the Sommerfeld factor of Yukawa interactions with arbitrary partial waves, which is exact in the Coulomb limit. It(More)
The increasing need for drug delivery systems that improve specificity and activity and at the same time reduce toxicity to ensure maximum treatment safety has led to the development of a great variety of drug vectors. Carriers based on soft matter have particularly interesting characteristics. Herein we present the current standing of the research in this(More)
We investigate the amount of fine tuning of the electroweak scale in the presence of new physics beyond the MSSM, parametrized by higher dimensional operators. We show that these significantly reduce the MSSM fine tuning to ∆ < 10 for a Higgs mass between the LEPII bound and 130 GeV, and a corresponding scale M∗ of new physics as high as 30 to 65 times the(More)
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