104 research outputs found
Supersymmetric Higgs singlet effects on FCNC observables
Higgs singlet superfields, usually present in extensions of the Minimal
Supersymmetric Standard Model (MSSM) which address the -problem, such as
the Next-to-Minimal Supersymmetric Standard Model (NMSSM) and the Minimal
Nonminimal Supersymmetric Standard Model (mnSSM), can have significant
contributions to -meson flavour-changing neutral current observables for
large values of \tan\beta \gsim 50. Illustrative results are presented
including effects on the and on the rare decay . In
particular, we find that in the NMSSM, the branching ratio for
can be enhanced or even suppressed with respect to the
Standard Model prediction by more than one order of magnitude.Comment: 3 pages, 4 figures, submitted to SUSY08 proceeding
Supersymmetric Higgs Singlet Effects on B-Meson FCNC Observables at Large tan(beta)
Higgs singlet superfields are usually present in most extensions of the
Minimal Supersymmetric Standard Model (MSSM) that address the mu-problem, such
as the Next-to-Minimal Supersymmetric Standard Model (NMSSM) and the Minimal
Nonminimal Supersymmetric Standard Model (MNSSM). Employing a gauge- and
flavour-covariant effective Lagrangian formalism, we show how the singlet Higgs
bosons of such theories can have significant contributions to B-meson
flavour-changing neutral current (FCNC) observables for large values of
at the 1-loop level. Illustrative results
are presented including effects on the B_s and B_d mass differences and on the
rare decay . In particular, we find that depending on the
actual value of the lightest singlet pseudoscalar mass in the NMSSM, the
branching ratio for can be enhanced or even suppressed with
respect to the Standard Model prediction by more than one order of magnitude.Comment: 28 pages, 8 figures, LaTeX. Minor updates. Version to be published in
PR
Measuring Anomalous Couplings in H->WW* Decays at the International Linear Collider
Measurement of the Higgs coupling to W-bosons is an important test of our
understanding of the electroweak symmetry breaking mechanism. We study the
sensitivity of the International Linear Collider (ILC) to the presence of
anomalous HW+W- couplings using ZH -> nu nu WW* -> nu nu 4j events. Using an
effective Lagrangian approach, we calculate the differential decay rates of the
Higgs boson including the effects of new dimension-5 operators. We present a
Monte Carlo simulation of events at the ILC, using a full detector simulation
based on geant4 and a real event reconstruction chain. Expected constraints on
the anomalous couplings are given.Comment: 18 pages, 7 figures, 1 tabl
in the NMSSM at large tan beta
We investigate the effects of the radiatively-generated tan beta-enhanced
Higgs-singlet Yukawa couplings on the decay in the
NMSSM, where is the lightest CP-odd scalar. This radiative coupling is
found to dominate in the case of a highly singlet Higgs pseudoscalar. The
branching ratio for the production of such a particle is shown to be within a
few orders of magnitude of current experimental constraints across a
significant region of parameter space. This represents a potentially observable
signal for experiments at present B-factories.Comment: 9 pages, LaTeX, 2 figures. Second result set for tan(beta)=10
included, clarifying remarks added, references updated. Version to be
published in Physics Letters
Higgs boson pair production through gauge boson fusion at linear colliders within the general 2HDM
Inclusive Higgs boson pair production through the mechanism of gauge boson
fusion e^{+} e^{-} -> V* V* -> h h + X (V=W,Z) in the general Two-Higgs-Doublet
Model (2HDM), with h=h^0,H^0,A^0,H^{\pm}, is analyzed at order \alpha^4_{ew} in
the linear colliders ILC and CLIC. This kind of processes is highly sensitive
to the trilinear Higgs (3H) boson self-interactions and hence can be a true
keystone in the reconstruction of the Higgs potential. For example, in the ILC
at 1 TeV, the most favorable scenarios yield cross-sections up to roughly 1 pb,
thus entailing 10^5 events per 100 fb^{-1} of integrated luminosity, whilst
remaining fully consistent with the perturbativity and unitarity bounds on the
3H couplings, the electroweak precision data and the constraints from
BR(b->s\gamma). Comparing with other competing mechanisms, we conclude that the
Higgs boson-pair events could be the dominant signature for Higgs-boson
production in the TeV-class linear colliders for a wide region of the 2HDM
parameter space, with no counterpart in the Minimal Supersymmetric Standard
Model. Owing to the extremely clean environment of these colliders, inclusive
2H events should allow a comfortable tagging and might therefore open
privileged new vistas into the structure of the Higgs potential.Comment: LaTeX, 17 pages, 5 figures, 3 Tables. Extended discussion, Fig.4
corrected. Accepted in Phys. Lett.
Supplementing High-Density SNP Microarrays for Additional Coverage of Disease-Related Genes: Addiction as a Paradigm
Commercial SNP microarrays now provide comprehensive and affordable coverage of the human genome. However, some diseases have biologically relevant genomic regions that may require additional coverage. Addiction, for example, is thought to be influenced by complex interactions among many relevant genes and pathways. We have assembled a list of 486 biologically relevant genes nominated by a panel of experts on addiction. We then added 424 genes that showed evidence of association with addiction phenotypes through mouse QTL mappings and gene co-expression analysis. We demonstrate that there are a substantial number of SNPs in these genes that are not well represented by commercial SNP platforms. We address this problem by introducing a publicly available SNP database for addiction. The database is annotated using numeric prioritization scores indicating the extent of biological relevance. The scores incorporate a number of factors such as SNP/gene functional properties (including synonymy and promoter regions), data from mouse systems genetics and measures of human/mouse evolutionary conservation. We then used HapMap genotyping data to determine if a SNP is tagged by a commercial microarray through linkage disequilibrium. This combination of biological prioritization scores and LD tagging annotation will enable addiction researchers to supplement commercial SNP microarrays to ensure comprehensive coverage of biologically relevant regions
Association of the OPRM1 Variant rs1799971 (A118G) with Non-Specific Liability to Substance Dependence in a Collaborative de novo Meta-Analysis of European-Ancestry Cohorts
Peer reviewe
Imaging biomarker roadmap for cancer studies.
Imaging biomarkers (IBs) are integral to the routine management of patients with cancer. IBs used daily in oncology include clinical TNM stage, objective response and left ventricular ejection fraction. Other CT, MRI, PET and ultrasonography biomarkers are used extensively in cancer research and drug development. New IBs need to be established either as useful tools for testing research hypotheses in clinical trials and research studies, or as clinical decision-making tools for use in healthcare, by crossing 'translational gaps' through validation and qualification. Important differences exist between IBs and biospecimen-derived biomarkers and, therefore, the development of IBs requires a tailored 'roadmap'. Recognizing this need, Cancer Research UK (CRUK) and the European Organisation for Research and Treatment of Cancer (EORTC) assembled experts to review, debate and summarize the challenges of IB validation and qualification. This consensus group has produced 14 key recommendations for accelerating the clinical translation of IBs, which highlight the role of parallel (rather than sequential) tracks of technical (assay) validation, biological/clinical validation and assessment of cost-effectiveness; the need for IB standardization and accreditation systems; the need to continually revisit IB precision; an alternative framework for biological/clinical validation of IBs; and the essential requirements for multicentre studies to qualify IBs for clinical use.Development of this roadmap received support from Cancer Research UK and the Engineering and Physical Sciences Research Council (grant references A/15267, A/16463, A/16464, A/16465, A/16466 and A/18097), the EORTC Cancer Research Fund, and the Innovative Medicines Initiative Joint Undertaking (grant agreement number 115151), resources of which are composed of financial contribution from the European Union's Seventh Framework Programme (FP7/2007-2013) and European Federation of Pharmaceutical Industries and Associations (EFPIA) companies' in kind contribution
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