103 research outputs found

    Inelastic Dark Matter at the LHC

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    We perform a model-independent study of inelastic dark matter at the LHC, concentrating on the parameter space with the mass splitting between the excited and ground states of dark matter above a few hundred MeV, where the direct detection experiments are unlikely to explore. The generic signatures of inelastic dark matter at the LHC are displaced pions together with a monojet plus missing energy, and can be tested at the 7 TeV LHC.Comment: 4 pages, 6 figure

    Searches with Mono-Leptons

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    We explore the implications of the mono-lepton plus missing transverse energy signature at the LHC, and point out its significance on understanding how dark matter interacts with quarks, where the signature arises from dark matter pair production together with a leptonically decaying W boson radiated from the initial state quarks. We derive limits using the existing W' searches at the LHC, and find an interesting interference between the contributions from dark matter couplings to up-type and down-type quarks. Mono-leptons can actually furnish the strongest current bound on dark matter interactions for axial vector (spin-dependent) interactions and iso-spin violating couplings. Should a signal of dark matter production be observed, this process can also help disentangle the dark matter couplings to up- and down-type quarks.Comment: four pages; six figures; the LHC 8 TeV results have been updated; final version in PL

    Particle Physics Implications for CoGeNT, DAMA, and Fermi

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    Recent results from the CoGeNT collaboration (as well as the annual modulation reported by DAMA/LIBRA) point toward dark matter with a light (5-10 GeV) mass and a relatively large elastic scattering cross section with nucleons (\sigma ~ 10^{-40} cm^2). In order to possess this cross section, the dark matter must communicate with the Standard Model through mediating particles with small masses and/or large couplings. In this Letter, we explore with a model independent approach the particle physics scenarios that could potentially accommodate these signals. We also discuss how such models could produce the gamma rays from the Galactic Center observed in the data of the Fermi Gamma Ray Space Telescope. We find multiple particle physics scenarios in which each of these signals can be accounted for, and in which the dark matter can be produced thermally in the early Universe with an abundance equal to the measured cosmological density.Comment: 4 pages, 2 figure

    Gamma Ray Line Constraints on Effective Theories of Dark Matter

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    A monochromatic gamma ray line results when dark matter particles in the galactic halo annihilate to produce a two body final state which includes a photon. Such a signal is very distinctive from astrophysical backgrounds, and thus represents an incisive probe of theories of dark matter. We compare the recent null results of searches for gamma ray lines in the galactic center and other regions of the sky with the predictions of effective theories describing the interactions of dark matter particles with the Standard Model. We find that the null results of these searches provide constraints on the nature of dark matter interactions with ordinary matter which are complementary to constraints from other observables, and stronger than collider constraints in some cases.Comment: 20 pages, 9 figure

    Search for dark matter produced in association with a hadronically decaying vector boson in pp collisions at sqrt (s) = 13 TeV with the ATLAS detector

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    A search is presented for dark matter produced in association with a hadronically decaying W or Z boson using 3.2 fb−1 of pp collisions at View the MathML sources=13 TeV recorded by the ATLAS detector at the Large Hadron Collider. Events with a hadronic jet compatible with a W or Z boson and with large missing transverse momentum are analysed. The data are consistent with the Standard Model predictions and are interpreted in terms of both an effective field theory and a simplified model containing dark matter

    Conception rate in Holstein cows treated with GnRH or hCG on the fifth day post artificial insemination during summer Taxa de concepção de vacas Holandesas tratadas com GnRH ou hCG no quinto dia após a inseminação artificial no verão

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    Lactating Holstein cows (n=158), at 213±112 days in milking and averaging 26±9kg of milk per day, were randomly assigned to one of three treatment groups: control (CG, n=52, saline), GnRH (GG, n=55, 100g gonadorelin), and hCG (HG, n=51, 2500IU) given five days after artificial insemination (AI). Rectal temperature was taken at the moment of AI and blood samples were collected five, seven, and 12 days after AI. Pregnancy was determined between 42 and 49 days after AI. Concentration of progesterone (P4) in serum (ng/ml, mean±SE) for CG, GG, and HG were, respectively, 2.7±0.4, 2.5±0.4, and 3.2±0.5 on day 5; 4.8±0.4, 4.2±0.4, and 5.7±0.5 on day 7; and 5.2±0.4, 6.9±0.4, and 8.5±0.5 on day 12 after AI. P4 concentration had proportional increase in serum between days 5 and 7 after AI (CG: 178%, GG: 168%, and HG: 178%), suggesting that the treatments did not induce a luteotropic effect on the existing corpus luteum (CL). Concentrations of P4 increased between days 7 and 12 in cows treated with GnRH and hCG (GG: 164%, and HG: 149%, PVacas da raça Holandesas em lactação (n=158) aos 213±112 dias de lactação e produção de 26±9kg leite/dia, foram aleatoriamente distribuídas em três grupos: controle (GC, n=52, salina); GnRH (GG, n=55, 100mcg de gonadorelina); e hCG (GH, n=51, 2500UI de hCG) aplicado no dia 5 após a inseminação artificial (IA). A temperatura retal foi verificada no momento da IA, e as amostras de sangue coletadas nos dias 5, 7 e 12 após a IA. A concepção foi determinada entre os dias 42 e 49 após IA. As concentrações séricas de progesterona (P4 - ng/ml, média±EPM) para GC, GG, e GH foram, respectivamente: no dia 5: 2,7±0,4, 2,5±0,4 e 3,2±0,4; no dia 7: 4,8±0,4, 4,2±0,4 e 5,7±0,5; e no dia 12 após a IA: 5,2±0,4, 6,9±0,4 e 8,5±0,5. O aumento proporcional na concentração sérica de P4 entre os dias 5 e 7 após IA (GC: 178%, GG: 168%, e GH: 178%) sugere que os tratamentos não induziram efeito luteotrópico no corpo lúteo (CL) existente. O aumento na P4 sérica entre os dias 7 e 12 nos animais tratados com GnRH ou hCG (GG: 164% e GH: 149%, P<0,01) em relação aos animais controle (GC: 18%, P=0,31), sugere a indução de novo CL. Os tratamentos com GnRH ou hCG aumentaram as taxas de concepção nas vacas com temperatura retal abaixo de 39,7°C (GC: 10,1%, n=26; GG: 36,8%, n=27 e GH: 32,8%, n=21), mas não em vacas com temperatura retal acima de 39,7°C (15,2% n=26; 17,8%, n=28 e 24,4%, n=30). Os resultados sugerem que a alta temperatura corporal pode mascarar os efeitos positivos do tratamento com GnRH ou hCG no dia 5 após a IA, na concepção

    Labor psychosocial risk factors, social support and Burnout syndrome in family doctors of three public health institutions, Guadalajara (México) [Factores de riesgo psicosocial laborales, apoyo social y síndrome de Burnout en médicos de familia de tres instituciones públicas de salud de Guadalajara (México)]

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    Objectives: To analyze negative labor psychosocial risks and social support, as incidents of Burnout syndrome in family doctors working in three public health institutions in Guadalajara, Mexico. Material and methods: The study was descriptive, analytical and comparative. The population consisted of family physicians based on the three institutions named as Institution 1, 2, and 3. We used three assessment tools: the Guide to Identify Psychosocial Factors of the Mexican Social Security Institute, the Diaz Veiga Modified Inventory of Social Resources and the rating scale of Maslach Burnout Inventory (MBI). Results: In general, we found adequate or good social support at the three institutions. The prevalences for the negative psychosocial factors were higher for the institution 3 (33.64 %), while for the Burnout syndrome, the institution showed a higher percentages (43.5 %). There were some significant associations between study variables. Conclusion: The need to reorganize certain working conditions, specifically those focused on work tasks, are essential for the prevention and reduction of the presence of Burnout Syndrome

    Labor psychosocial risk factors, social support and Burnout syndrome in family doctors of three public health institutions, Guadalajara (México) [Factores de riesgo psicosocial laborales, apoyo social y síndrome de Burnout en médicos de familia de tres instituciones públicas de salud de Guadalajara (México)]

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    Objectives: To analyze negative labor psychosocial risks and social support, as incidents of Burnout syndrome in family doctors working in three public health institutions in Guadalajara, Mexico. Material and methods: The study was descriptive, analytical and comparative. The population consisted of family physicians based on the three institutions named as Institution 1, 2, and 3. We used three assessment tools: the Guide to Identify Psychosocial Factors of the Mexican Social Security Institute, the Diaz Veiga Modified Inventory of Social Resources and the rating scale of Maslach Burnout Inventory (MBI). Results: In general, we found adequate or good social support at the three institutions. The prevalences for the negative psychosocial factors were higher for the institution 3 (33.64 %), while for the Burnout syndrome, the institution showed a higher percentages (43.5 %). There were some significant associations between study variables. Conclusion: The need to reorganize certain working conditions, specifically those focused on work tasks, are essential for the prevention and reduction of the presence of Burnout Syndrome
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