Search for heavy resonances decaying to two Higgs bosons in final states containing four b quarks

A search is presented for narrow heavy resonances X decaying into pairs of Higgs bosons (H) in proton-proton collisions collected by the CMS experiment at the LHC at root s = 8 TeV. The data correspond to an integrated luminosity of 19.7 fb(-1). The search considers HH resonances with masses between 1 and 3 TeV, having final states of two b quark pairs. Each Higgs boson is produced with large momentum, and the hadronization products of the pair of b quarks can usually be reconstructed as single large jets. The background from multijet and t (t) over bar events is significantly reduced by applying requirements related to the flavor of the jet, its mass, and its substructure. The signal would be identified as a peak on top of the dijet invariant mass spectrum of the remaining background events. No evidence is observed for such a signal. Upper limits obtained at 95 confidence level for the product of the production cross section and branching fraction sigma(gg -> X) B(X -> HH -> b (b) over barb (b) over bar) range from 10 to 1.5 fb for the mass of X from 1.15 to 2.0 TeV, significantly extending previous searches. For a warped extra dimension theory with amass scale Lambda(R) = 1 TeV, the data exclude radion scalar masses between 1.15 and 1.55 TeV

Measurement of the top quark mass using charged particles in pp collisions at root s=8 TeV

Peer reviewe

Economía dinámica : modelos caóticos

Fil: Berruti, Andrés Alejandro. Universidad Nacional de Cuyo. Facultad de Ciencias Económica

Geographic Aspects of Poverty and Health in Tanzania: Does Living in a Poor Area Matter?

Previous studies have consistently found that that there is an inverse relationship between household level poverty and health status, and that poor people tend to live in poor communities. However, what is not well understood is whether and how the average economic status at the community level plays a role in the household poverty–health relationship. This study investigates the concentration of poverty at the\ud community level in Tanzania and its association with the availability and quality of primary health care services, the utilization of primary health care services, and health outcomes among both poor and nonpoor households. The analysis uses an innovative approach of linking household-level data from 1996 Tanzania Demographic and Health Survey with facility information from the 1996 Tanzania Service\ud Availability Survey. A principle component method is used to rank households separately by urban/rural status according to the reported levels of assets ownership and living conditions, and then classifies communities into three socioeconomic groups based on the proportion of households belonging the poorest wealth tercile. On average, both poor and non-poor households living in low poverty concentration areas were found to have better health outcomes and service utilization rates than their counterparts living in high poverty concentration clusters. Consistent with the finding is that high poverty concentration areas were farther way from facilities offering primary health care than were low poverty concentration areas. Moreover, the facilities closest to the high poverty concentration areas had fewer\ud doctors, medical equipment, and drugs. Among poor communities in rural areas, the ten communities with the best women’s body mass index (BMI) measures were found to have access to facilities with a greater availability of equipment and drugs than the ten communities with the worst BMI measures. Although this study does not directly measure quality, the characteristics that differentiate high poverty\ud concentration clusters from low poverty concentration clusters point to quality as more important than physical access among the study population.\u

Maternal and child health and family planning service utilization in Guatemala: implications for service integration

Does the utilization of modern maternal and child health (MCH) services influence subsequent contraceptive use? The answer to this question holds important implications for proposals which advocate MCH and family planning service integration. This study uses data from the 1995/6 Guatemalan Demographic Health Survey and its 1997 Providers Census to test the influence of MCH service utilization on individual contraceptive use decisions. We use a full-information maximum likelihood regression model to control for unobserved heterogeneity. This model produces estimates of the MCH effect, independent of individual women's underlying receptiveness to MCH and contraceptive messages. The results of the analysis indicate that the intensity of MCH service use is indeed positively associated with subsequent contraceptive use among Guatemalan women, even after controlling for observed and unobserved individual- , household- , and community-level factors. Importantly, this finding holds even after controlling for the unobserved factors that 'predispose' some women to use both types of services. Simulations reveal that, for these Guatemalan women, key determinants such as age and primary schooling work indirectly through MCH service use to increase contraceptive utilization.Contraceptives MCH Guatemala Family planning