Impact of semi-annihilations on dark matter phenomenology - an example of Z_N symmetric scalar dark matter

We study the impact of semi-annihilations x_i x_j x_k X, where x_i is any dark matter and X is any standard model particle, on dark matter phenomenology. We formulate minimal scalar dark matter models with an extra doublet and a complex singlet that predict non-trivial dark matter phenomenology with semi-annihilation processes for different discrete Abelian symmetries Z_N, N>2. We implement two such example models with Z_3 and Z_4 symmetry in micrOMEGAs and work out their phenomenology. We show that both semi-annihilations and annihilations involving only particles from two different dark matter sectors significantly modify the dark matter relic abundance in this type of models. We also study the possibility of dark matter direct detection in XENON100 in those models.Comment: 17 pages, 4 figure

Status and prospects of the nMSSM after LHC Run-1

The new minimal supersymmetric standard model (nMSSM), a variant of the general next to minimal supersymmetric standard model (NMSSM) without $Z_3$ symmetry, features a naturally light singlino with a mass below 75 GeV. In light of the new constraints from LHC Run-1 on the Higgs couplings, sparticles searches and flavour observables, we define the parameter space of the model which is compatible with both collider and dark matter (DM) properties. Among the regions compatible with these constraints, implemented through NMSSMTools, SModelS and MadAnalysis 5, only one with a singlino lightest supersymmetric particle (LSP) with a mass around 5 GeV can explain all the DM abundance of the universe, while heavier mixed singlinos can only form one of the DM components. Typical collider signatures for each region of the parameter space are investigated. In particular, the decay of the 125 GeV Higgs into light scalars and/or pseudoscalars and the decay of the heavy Higgs into charginos and neutralinos, provide distinctive signatures of the model. Moreover, the sfermion decays usually proceed through heavier neutralinos rather than directly into the LSP, as the couplings to the singlino are suppressed. We also show that direct detection searches are complementary to collider ones, and that a future ton-scale detector could completely probe the region of parameter space with a LSP mass around 65 GeV.Comment: 33 pages, 9 figures. Version accepted for publication in JHE

Higgs Phenomenology of Minimal Universal Extra Dimensions

The minimal model of Universal Extra Dimensions (MUED) is briefly reviewed. We explain how the cross-sections for Higgs production via gluon fusion and decay into two photons are modified, relative the the Standard Model (SM) values, by KK particles running in loops, leading to an enhancement of the gg to h to two photons and gg to h to W+W- cross-sections. ATLAS and CMS searches for the SM Higgs in these channels are reinterpreted in the context of MUED and used to place new limits on the MUED parameter space. Only a small region of between 1 and 3 GeV around mh = 125 GeV for 500 GeV < 1/R < 1600 GeV remains open at the 95 % confidence level.Comment: Presented at the 2011 Hadron Collider Physics symposium (HCP-2011), Paris, France, November 14-18 2011, 3 pages, 4 figure

Uncertainties in the Prediction of the Relic Density of Supersymmetric Dark Matter

We investigate how well the relic density of dark matter can be predicted in mSUGRA. We determine the parameters to which the relic density is most sensitive and quantify the collider accuracy needed to match the accuracy of WMAP and PLANCK.Comment: 4 pages, 1 figure, presented at LCWS, Paris, April 200

Comparison of SUSY spectrum calculations and impact on the relic density constraints from WMAP

We compare results of four public supersymmetric (SUSY) spectrum codes, Isajet, Softsusy, Spheno and Suspect to estimate the present-day uncertainty in the calculation of the relic density of dark matter in mSUGRA models. We find that even for mass differences of about 1% the spread in the obtained relic densities can be 10%. In difficult regions of the parameter space, such as large tan(beta) or large m_0, discrepancies in the relic density are much larger. We also find important differences in the stau co-annihilation region. We show the impact of these uncertainties on the bounds from WMAP for several scenarios, concentrating on the regions of parameter space most relevant for collider phenomenology. We also discuss the case of non-zero A_0 and the stop co-annihilation region. Moreover, we present a web application for the online comparison of the spectrum codes.Comment: 26 pages, 6 figures, 10 tables; version to appear in PR

Bibliographie générale sur les Îles-de-la-Madeleine

Un aspect secondaire mais important de la recherche poursuivie aux îles-de-la-Madeleine a été l'inventaire bibliographique. Cette tâche ne fut pas sans poser de nombreux problèmes. En effet, les répertoires bibliographiques que nous avons l'habitude de consulter mentionnent rarement les Iles-de-la-Madeleine. Comme on pourra le constater, ce n'est certainement pas faute de publications. Plusieurs de celles-ci furent souvent découvertes par hasard. Nous sommes cependant redevables à trois auteurs, qui se sont d'ailleurs inspirés les uns des autres; il s'agit de: Noël Falaise, Louis-Edmond Hamelin et Léonise Harvey. Ces trois ouvrages constituent un point de départ mais ne fournissent aucun renseignement sur les publications récentes, non plus que sur la plupart des rapports de recherche non publies. Il ne serait donc pas surprenant qu'un certain nombre de références aient été oubliées. Cette bibliographie ne perd pas de son intérêt pour autant, parce que le chercheur intéressé par n'importe quel sujet pourra y trouver rapidement les travaux qui ont pu être faits dans sa discipline. Pour faciliter la consultation, la bibliographie est divisée en six sections, distinguant les publications des rapports. Voici le plan utilisé:I. GÉNÉRALII. BIO-PHYSIQUEa) livres et articles de revues b) rapports III. ÉCONOMIQUEa) livres et articles de revues b) rapports IV. SOCIO-CULTURELa) livres et articles de revues b) rapports V. FILMSVI. JOURNAU

Indirect search for dark matter with micrOMEGAs2.4

We present a new module of micrOMEGAs devoted to the computation of indirect signals from dark matter annihilation in any new model with a stable weakly interacting particle. The code provides the mass spectrum, cross-sections, relic density and exotic fluxes of gamma rays, positrons and antiprotons. The propagation of charged particles in the Galactic halo is handled with a new module that allows to easily modify the propagation parameters.Comment: 24 pages, 6 figures, typos corrected, acknowledgements modifie

Key Beliefs for Targeted Interventions to Increase Physical Activity in Children: Analyzing Data from an Extended Version of the Theory of Planned Behaviour

Given the high prevalence of overweight and low levels of physical activity among children, a better understanding of physical activity behaviour is an important step in intervention planning. This study, based on the theory of planned behaviour, was conducted among 313 fifth graders and their parents. Children completed a computer-based questionnaire to evaluate theoretical constructs and behaviour. Additional information was obtained from parents by means of a questionnaire. Correlates of children's physical activity were intention and self-identity. Determinants of intention were self-efficacy, self-identity, and attitude. Parental variables were mediated through cognitions. Among girls, practicing sedentary activities was an additional negative determinant of intention. Key beliefs of boys and girls were related to time management and difficulties associated with physical activity. For girls, social identification as an active girl was another important belief related to positive intention. This study provides theory-based information for the development of more effective interventions aimed at promoting physical activity among children

On the jumps of degrees below an recursively enumerable degree

We consider the set of jumps below a Turing degree, given by JB(a) = {x(1) : x <= a}, with a focus on the problem: Which recursively enumerable (r.e.) degrees a are uniquely determined by JB(a)? Initially, this is motivated as a strategy to solve the rigidity problem for the partial order R of r.e. degrees. Namely, we show that if every high(2) r.e. degree a is determined by JB(a), then R cannot have a nontrivial automorphism. We then defeat the strategy-at least in the form presented-by constructing pairs a(0), a(1) of distinct r.e. degrees such that JB(a(0)) = JB(a(1)) within any possible jump class {x : x' = c}. We give some extensions of the construction and suggest ways to salvage the attack on rigidity