148 research outputs found
Neutrino masses and mixings in the baryon triality constrained minimal supersymmetric standard model
We discuss how the experimental neutrino oscillation data can be realized in
the framework of the baryon triality () constrained supersymmetric
Standard Model (cSSM). We show how to obtain phenomenologically viable
solutions, which are compatible with the recent WMAP observations. We present
results for the hierarchical, inverted and degenerate cases which illustrate
the possible size and structure of the lepton number violating couplings. We
work with a new, as yet unpublished version of SOFTSUSY, where we implemented
full one--loop neutrino masses. Finally, we shortly discuss some
phenomenological implications at the LHC.Comment: 25 pages, 17 figure
Multi-Parton Interactions at the LHC
We review the recent progress in the theoretical description and experimental
observation of multiple parton interactions. Subjects covered include
experimental measurements of minimum bias interactions and of the underlying
event, models of soft physics implemented in Monte Carlo generators,
developments in the theoretical description of multiple parton interactions and
phenomenological studies of double parton scattering. This article stems from
contributions presented at the Helmholtz Alliance workshop on "Multi-Parton
Interactions at the LHC", DESY Hamburg, 13-15 September 2010.Comment: 68 page
Linear Collider Test of a Neutrinoless Double Beta Decay Mechanism in left-right Symmetric Theories
There are various diagrams leading to neutrinoless double beta decay in
left-right symmetric theories based on the gauge group SU(2)_L x SU(2)_R. All
can in principle be tested at a linear collider running in electron-electron
mode. We argue that the so-called lambda-diagram is the most promising one.
Taking the current limit on this diagram from double beta decay experiments, we
evaluate the relevant cross section e e to W_L W_R, where W_L is the Standard
Model W-boson and W_R the one from SU(2)_R. It is observable if the life-time
of double beta decay and the mass of the W_R are close to current limits. Beam
polarization effects and the high-energy behaviour of the cross section are
also analyzed.Comment: 17 pages, 6 figures. v2: minor changes, references added, to be
published in EPJ
Same-sign W pair production as a probe of double parton scattering at the LHC
We study the production of same-sign W boson pairs at the LHC in double
parton interactions. Compared with simple factorised double parton
distributions (dPDFs), we show that the recently developed dPDFs, GS09, lead to
non-trivial kinematic correlations between the W bosons. A numerical study of
the prospects for observing this process using same-sign dilepton signatures,
including same-sign WWjj, di-boson and heavy flavour backgrounds, at 14 TeV
centre-of-mass energy is then performed. It is shown that a small excess of
same-sign dilepton events from double parton scattering over a background
dominated by single scattering WZ(gamma*) production could be observed at the
LHC.Comment: 14 pages, 8 figures. Added references, slight changes in the text
Antiplasmodial and cytotoxic activities of flavonoids and arylbenzofuran derivatives from Morus mesozygia
Morus mesozygia Stapf (Moraceae) is a plant found in many regions and used in treating many diseases including malaria and fever. Fractionation of the methanolic extract of its stem bark, using various chromatographic methods has led to the isolation and identification of 3 flavonoids: artocarpesin, artochamin C and kushenol E. And 4 arylbenzofuran derivatives: moracin M, moracin C, moracin L and mulberofuran F. The methanolic extract and the seven isolated compounds were tested for antiplasmodial activity against the chloroquine-resistant FcB1 Plasmodium falciparum strain and cytotoxicity on MCF-7 human breast cancer cells. Relating to the antiplasmodial activity, it was found that all compounds were active against the FcB1 strain of Plasmodium with artocarpesin, koushenol E and mulberrofuran F showing particular potency (with the median inhibitory concentrations IC50 = 2.5-2.6 μg/ml). Cytotoxicity tests performed on MCF-7 cells revealed all the IC50 varying from <1.0 to 5.0 ± 0.6 μg/mL. A structure – activity relationship is discussed
School Absenteeism As an Adjunct Surveillance Indicator: Experience during the Second Wave of the 2009 H1N1 Pandemic in Quebec, Canada
A school absenteeism surveillance system was implemented in the province of Quebec, Canada during the second wave of the 2009 H1N1 pandemic. This paper compares this surveillance approach with other available indicators.All (3432) elementary and high schools from Quebec were included. Each school was required to report through a web-based system any day where the proportion of students absent for influenza-like illness (ILI) exceeded 10% of current school enrolment.Between October 18 and December 12 2009, 35.6% of all schools met the 10% absenteeism threshold. This proportion was greater in elementary compared to high schools (40% vs 19%) and in smaller compared to larger schools (44% vs 22%). The maximum absenteeism rate was reached the first day of reporting or within the next two days in 55% and 31% of schools respectively. The first reports and subsequent peak in school absenteeism provincially preceded the peak in paediatric hospitalization by two and one weeks, respectively. Trends in school surveillance otherwise mirrored other indicators.During a pandemic, school outbreak surveillance based on a 10% threshold appears insufficient to trigger timely intervention within a given affected school. However, school surveillance appears well-correlated and slightly anticipatory compared to other population indicators. As such, school absenteeism warrants further evaluation as an adjunct surveillance indicator whose overall utility will depend upon specified objectives, and other existing capacity for monitoring and response
- …