1,942 research outputs found

    {\Large{\bf Higgs or Neutral Vector Boson Production with a WW Pair in {\LARGE γγ\gamma \gamma} Collisions}}

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    Exploiting the fact that WW pair production in high-energy γγ\gamma \gamma collisions is very large, we use this process to trigger Higgs, ZZ or photon radiation. We find that there are sizeable rising cross-sections for triple bosons production. At energies about 1TeV1TeV the new mechanism for Higgs production becomes very competitive with the dominant Higgs production processes in e+ee^+e^- and eγe \gamma reactions. The effect of different polarized photon spectra obtained through back-scattered laser light on the electron beam of a linear collider is investigated . We give a special attention to the search of the intermediate mass Higgs in WWHWWH production and discuss how to effectively suppress the backgrounds.Comment: ENSLAPP-A-430/93, 14 pages, plus 6 figures available through mail or fax upon reques

    Invisible Decays of the Supersymmetric Higgs and Dark Matter

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    We discuss effects of the light sparticles on decays of the lightest Higgs in a supersymmetric model with nonuniversal gaugino masses at the high scale, focusing on the `invisible' decays into neutralinos. These can impact significanlty the discovery possibilities of the lightest Higgs at the LHC. We show that due to these decays, there exist regions of the M2μM_2-\mu space where the B.R. (hγγ)(h \to \gamma \gamma) becomes dangerously low even after imposing the LEP constraints on the sparticle masses, implying a possible preclusion of its discovery in the γγ\gamma \gamma channel. We find that there exist regions in the parameter space with acceptable relic density and where the ratio B.R.(hγγ)SUSYB.R.(hγγ)SM{B.R. (h \to \gamma \gamma)_{SUSY} \over B.R. (h \to \gamma \gamma)_{SM}} falls below 0.6, implying loss of signal in the γγ\gamma \gamma channel. These regions correspond to χ~1+,χ~20\tilde \chi_1^+, \tilde \chi_2^0 masses which should be accessible already at the Tevatron. Further we find that considerations of relic density put lower limit on the U(1) gaugino mass parameter M1M_1 independently of μ,tanβ\mu, \tan \beta and m0m_0.Comment: 17 pages, 11 figures, Talk presented at Appi2002, Accelerator and Particle Physics Institute, Appi, Iwate, Japan, February 13--16 200

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

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    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

    Higgs Phenomenology of Minimal Universal Extra Dimensions

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    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

    Extracting constraints from direct detection searches of supersymmetric dark matter in the light of null results from the LHC in the squark sector

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    The comparison of the results of direct detection of Dark Matter, obtained with various target nuclei, requires model-dependent, or even arbitrary, assumptions. Indeed, to draw conclusions either the spin-dependent (SD) or the spin-independent (SI) interaction has to be neglected. In the light of the null results from supersymmetry searches at the LHC, the squark sector is pushed to high masses. We show that for a squark sector at the TeV scale, the framework used to extract contraints from direct detection searches can be redefined as the number of free parameters is reduced. Moreover, the correlation observed between SI and SD proton cross sections constitutes a key issue for the development of the next generation of Dark Matter detectors.Comment: Figure 3 has been updated. Conclusions unchange

    Association between physical activity motives and type of physical activity in children

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    Abstract: Objectives: Motives for participating in a specific type of physical activity (PA) may differ across PA type in youth. We studied the relationship between PA motives and type of PA engaged in by youth. Design: Cross-sectional analysis using data from the Monitoring Activities of Teenagers to Comprehend their Habits (MATCH) study. Method: 802 students age 10-11 years from 17 primary schools in New-Brunswick, Canada completed a questionnaire that collected data on type of PA participated in (individual, group-based, organized, non-organized), PA motives (enjoyment, social affiliation, competence, fitness/health, appearance) and attainment of PA guidelines (60 minutes of moderate-to-vigorous PA per day). The associations between PA motives and PA type and between PA motives and attainment of PA recommendations were assessed in multilevel logistic regression models. Results: Endorsing enjoyment motives was associated with participation in organized PA (Odds Ratio, 95% Confidence Interval: 1.54, 1.24-1.91). Competence motives were associated with participation in group-based PA (1.27, 1.11-1.46) and achievement of PA recommendations (1.95, 1.37-2.78). Conclusion: Targeting enjoyment and competence motives may be associated with increased participation in organized and group-based PA as well as with an increased likelihood of meeting PA guidelines in youth

    Cognitive behavioral therapy for insomnia in older adults

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    Insomnia is associated with significant morbidity and is often a persistent problem, particularly in older adults. It is important to attend to this complaint and not assume that it will remit spontaneously. In many cases, unfortunately, insomnia remains unrecognized and untreated, often because it is presumed that insomnia is an inevitable consequence of aging. Although the sleep structure naturally changes with advancing age, these changes are not necessarily associated with complaints of poor sleep, distress, or daytime consequences, while chronic insomnia clearly is. There is increasing evidence that cognitive behavioral therapy (CBT) is effective for the management of chronic insomnia in the elderly and that it is of significant benefit for insomnia comorbid with medical and psychological conditions, also more prevalent in older age. The aim of this article is to familiarize clinicians working with older adults with the different components of CBT for insomnia and how to adapt the treatment to this population. A clinical case and session-by-session implementation of CBT for insomnia are described to illustrate information and guidelines provided in this article

    Spousal support and relationship happiness in adults with type 2 diabetes and their spouses

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    Objectives The purpose of this study was to examine the association between the perceptions of spousal support self-efficacy in terms of dietary self-care and relationship happiness. Methods Forty-six couples, in which only one spouse has type 2 diabetes, completed questionnaires on perceptions of spousal support self-efficacy and relationship happiness. Results Using an actor-partner interdependence model, we found that when persons with type 2 diabetes were more confident in their spouse’s ability to provide them with support regarding their dietary self-care, they reported more relationship happiness. We also found that when their spouse without diabetes was more confident in their own abilities to provide such support to their partner, they reported more relationship happiness. However, the person with diabetes’ confidence in their spouse’s support abilities and the spouse’s confidence in their own support abilities were not associated with the other partner’s relationship happiness. Conclusions This study offers a unique dyadic perspective on the determinants of happiness for couples in which one spouse has type 2 diabetes. The perceived quality of spousal support appears to be associated with relationship happiness in committed couples managing diabetes, regardless of the actual support received or provided

    Effects of water volume rates on spray deposition and control of tarnished plant bug [Hemiptera : Miridae] in strawberry crops

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    Des expériences ont été effectuées pour vérifier l'effet de trois volumes d'application de bouillie sur la couverture de fraisiers ( Fragaria ananassa: cultivars Kent et Chambly) et sur l'efficacité d'un insecticide contre la punaise terne ( Lygus lineolaris). Les expériences ont été réalisées à un taux constant de matière active pour des volumes de bouillie de 500 et 1500 L ha-1. La couverture des plants a été mesurée à l'aide d'un traceur fluorescent pour des volumes d'application de 500, 1000 et 1500 L ha-1 sur des échantillons pris au sol et sur différentes parties des plants. Les populations de punaise terne ont été évaluées 24 heures avant et après les traitements avec du malathion (4,5 kg m.a. ha-1) en utilisant 0, 500 et 1500 L ha-1. Les données normalisées pour un taux constant de matière active ont montré qu'une augmentation du volume de bouillie de 500 à 1500 L ha-1 n'avait généralement pas d'effet sur les quantités de traceur retrouvées. À quelques occasions, une augmentation du volume d'application a entraîné une baisse des quantités de traceur retrouvées, par exemple sur les feuilles du bas et du sommet du feuillage (Kent) et des sépales (Kent). Le contrôle des populations de punaise terne était acceptable sur le plan commercial à 500 et à 1500 L ha-1.Field experiments were performed on the effect of three volumes of application on spray deposition and insecticidal efficacy against the tarnished plant bug (Lygus lineolaris) in two strawberry (Fragaria ananassa) cultivars, Kent and Chambly. The rate of application of malathion was kept constant at 4.5 kg a.i. ha-1 for volumes of application of 500 and 1500 L ha-1. Plant coverage was measured using a fluorescent tracer applied at volumes of application of 500, 1000 and 1500 L ha-1. The tracer was recovered from samples taken from different plant locations and on the ground. Tarnished plant bug populations were evaluated 24 hours before and after insecticidal treatment. When coverage data were normalized for a fixed active ingredient rate, an increase in the volume of application from 500 to 1500 L ha-1 frequently had no effect on the amount of tracer recovered at the various locations. On some occasions, an increase in volume of application resulted in a decrease in the amount of tracer recovered, i.e. leaves at the top and bottom of the canopy (Kent), sepals (Kent). Tarnished plant bug population control was commercially acceptable at 500 and 1500 L ha-1
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