Lower limit on the neutralino mass in the general MSSM

We discuss constraints on SUSY models with non-unified gaugino masses and R_P conservation. We derive a lower bound on the neutralino mass combining the direct limits from LEP, the indirect limits from gmuon, bsgamma, Bsmumu and the relic density constraint from WMAP. The lightest neutralino (mneutralino=6GeV) is found in models with a light pseudoscalar with MA<200GeV and a large value for $tan\beta$. Models with heavy pseudoscalars lead to mneutralino>18(29)GeV for $\tan\beta=50(10)$. We show that even a very conservative bound from the muon anomalous magnetic moment can increase the lower bound on the neutralino mass in models with mu<0 and/or large values of $\tan\beta$. We then examine the potential of the Tevatron and the direct detection experiments to probe the SUSY models with the lightest neutralinos allowed in the context of light pseudoscalars with high $\tan\beta$. We also examine the potential of an e+e- collider of 500GeV to produce SUSY particles in all models with neutralinos lighter than the W. In contrast to the mSUGRA models, observation of at least one sparticle is not always guaranteed.Comment: 37 pages, LateX, 16 figures, paper with higher resolution figures available at http://wwwlapp.in2p3.fr/~boudjema/papers/bound-lsp/bound-lsp.htm

Probing SUSY CP Violation in Two-Body Stop Decays at the LHC

We study CP asymmetries in two-body decays of top squarks into neutralinos and sleptons at the LHC. These asymmetries are used to probe the CP phases possibly present in the stop and neutralino sector of the Minimal Supersymmetric Standard Model. Taking into account bounds from experimental electric dipole moment searches, we identify areas in the mSUGRA parameter space where CP asymmetries can be sizeable and discuss the feasibility of their observation at the LHC. As a result, potentially detectable CP asymmetries in stop decays at the LHC are found, motivating further detailed experimental studies for probing SUSY CP phases.Comment: 38 pages, 13 figures, error in Yukawa coupling corrected, revised benchmark scenario and figures, JHEP versio

Classical and molecular cytogenetic analysis in head and neck squamous cell carcinomas

Head and neck carcinomas represent the sixth most frequent type of cancer in the world, and 90% are derived from squamous cells (HNSCC). In this study of 15 HNSCC cases, extensive aneuploidy was detected by G banding in most tumors. The most frequently observed numerical changes involved gain of a chromosome 22, and loss of chromosomes Y, 10, 17, and 19. The most frequent structural alteration was del(22)(q13.1). As compared to G-banding, fluorescence in situ hybridization (FISH) proved to be an effective technique for detecting aneuploidy. Interphase FISH with a chromosome 17 centromere probe disclosed a high frequency of monosomy for chromosome 17, in contrast with G-banding, by which clonal monosomy 17 was detected in only three of the tumors. Painting probes for chromosomes 5 and 16 were used to evaluate a selected series of HNSCC in which G-banding analysis had shown marker chromosomes. FISH analysis failed to confirm the origin of the marker chromosomes, but four out of five cases showed a significant loss of chromosomes 5. This difference between FISH and G-banding results may reflect the smaller number of metaphase analyzed as well as the criteria adopted for sorting these metaphases. Therefore results obtained solely by G-banding analysis should be considered with caution. Our data confirmed the involvement of chromosome 17 in head and neck squamous cell carcinomas