Comparison of Nonmesonic Hypernuclear Decay Rates Computed in Laboratory and Center-of-Mass Coordinates

In this work we compute the one-nucleon-induced nonmesonic hypernuclear decay rates of He-5(Lambda), C-12(Lambda) and C-13(Lambda) using a formalism based on the independent particle shell model in terms of laboratory coordinates. To ascertain the correctness and precision of the method, these results are compared with those obtained using a formalism in terms of center-of-mass coordinates, which has been previously reported in the literature. The formalism in terms of laboratory coordinates will be useful in the shell-model approach to two-nucleon-induced transitions.

Combination of t(t)over-bar cross section measurements and constraints on the mass of the top quark and its decays into charged Higgs bosons

We combine measurements of the top quark pair production cross section in p (p) over bar collisions in the l + jets, ll, and tau l final states ( where l is an electron or muon) at a center of mass energy of root s = 1.96 TeV in 1 fb(-1) of data collected with the D0 detector. For a top quark mass of 170 GeV/c(2), we obtain sigma(t (t) over bar) = 8.18(-0.87)(+0.98) pb in agreement with the theoretical prediction. Based on predictions from higher order quantum chromodynamics, we extract a mass for the top quark from the combined t (t) over bar cross section, consistent with the world average of the top quark mass. In addition, the ratios of t (t) over bar cross sections in different final states are used to set upper limits on the branching fractions B(t -> H(+)b -> tau(+) vb) and B(t -> H(+)b -> c (s) over barb) as a function of the charged Higgs boson mass.

Precise Measurement of the Top Quark Mass in the Dilepton Channel at D0

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Study of the mass and spin-parity of the Higgs boson candidate via its decays to Z boson pairs

A study is presented of the mass and spin-parity of the new boson recently observed at the LHC at a mass near 125 GeV. An integrated luminosity of 17.3 fb-1, collected by the CMS experiment in proton-proton collisions at center-of-mass energies of 7 and 8 TeV, is used. The measured mass in the ZZ channel, where both Z bosons decay to e or μ pairs, is 126.2±0.6(stat) ±0.2(syst) GeV. The angular distributions of the lepton pairs in this channel are sensitive to the spin-parity of the boson. Under the assumption of spin 0, the present data are consistent with the pure scalar hypothesis, while disfavoring the pure pseudoscalar hypothesis. © 2013 CERN. Published by the American Physical Society under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.

Studies of jet mass in dijet and W/Z + jet events

Invariant mass spectra for jets reconstructed using the anti-k T and CambridgeAachen algorithms are studied for different jet grooming techniques in data corresponding to an integrated luminosity of 5 fb-1, recorded with the CMS detector in proton-proton collisions at the LHC at a center-of-mass energy of 7 TeV. Leading-order QCD predictions for inclusive dijet and W/Z+jet production combined with parton-shower Monte Carlo models are found to agree overall with the data, and the agreement improves with the implementation of jet grooming methods used to distinguish merged jets of large transverse momentum from softer QCD gluon radiation. © 2013 CERN for the benefit of the CMS collaboration.

Determination of the top-quark pole mass and strong coupling constant from the t(t)over-bar production cross section in pp collisions at root s=7 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Dynamics of inter-modality re-weighting during human postural control

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

First Autochthonous Case of Canine Visceral Leishmaniasis in the Center of Rio Grande do Sul State, Brazil

Background: Leishmaniasis is one of the most important vector-borne diseases of humans. This parasitic disease can be caused by many species of Leishmania. In humans, different species of the parasite are associated with different forms of the disease, cutaneous and visceral. Among domesticated animals, dogs are the most important species in the epidemiology of this disease. Leishmania chagasi, an important zoonosis, is well established as the agent of visceral leishmaniasis in Brazil. The disease is endemic in north, northeast, midwest and southeast, and is transmitted to mammals by hematophagous insects such as the Lutzomyia longipalpis. In 2008, our research group has diagnosed a case of canine leishmaniasis in the municipality of Uruguaiana and subsequently there were several cases in the city and the neighbor municipality of Sao Borja. Most Brazilian states are endemic for leishmaniasis, with the exception of Rio Grande do Sul. In southern Brazil, the reports of humans and dogs infected by Leishmania spp. are the source of endemic area in the country. Therefore, the aim of this study is register the first clinical case of canine visceral leishmaniasis in the municipality of Santa Maria, RS.Case: In october 2010, a veterinary clinic of Santa Maria received a canine, female, Doberman, with two years of age. The animal had severe skin lesions on the head and limbs, pale mucous membranes, and enlarged lymph nodes. According to the owner, the animal showed progressive weight loss and anorexia for more than five days. During the clinical examination the blood was collected for hemogram and cytology of lymph nodes was performed by puncture aspiration with a fine needle. In the erythrogram, it was observed a decrease in the total number of erythrocytes (2.8 x 10(6)/mu L), hematocrit (21%), hemoglobin (6.8 g/dL) and platelets (98 x 10(3)/mu L). In the leucogram, any alteration was observed. The cytology of lymph nodes showed amastigotes forms, suggestive of the Leishmania spp. Based on this finding; we performed the blood collection for PCR, to confirm parasitism and to determine the species of Leishmania. At the molecular test was used PCR-specific for L. chagasi, and the result was positive.Discussion: This is the first autochthonous clinical case in the central region of the RS, non-endemic area for leishmaniasis. In serological studies of visceral leishmaniasis it was diagnosed in five asymptomatic dogs in the municipalities of Santa Maria, Julio de Castilhos and Itaara, however not confirmed by molecular analysis. In the municipalities of Cruz Alta and Uruguaiana cases of L. chagasi have been reported in dogs which previously resided in Leishmania sp. endemic areas. The municipality of Sao Borja had the first record of L. longipalpis in the RS during the leishmaniasis outbreak in 2008-2009. In the central region of the RS vector has not been found, but because in this first autochthonous case dog in Santa Maria believe that the parasite is present and/or doing other insect transmission of leishmaniasis. Clinical signs associated with hematologic and coagulation disorders observed in the canine are commonly described in symptomatic dogs in endemic regions. This case of autochthonous leishmaniasis reinforces the idea of the vector presence in Santa Maria, center of the RS. We believe that canine leishmaniasis is an emerging disease in the southern region of Brazil.

The center of the incisive papilla for the selection of complete denture maxillary anterior teeth in 4 racial groups

Objectives: To evaluate the use of the center of the incisive papilla as a guide for the selection of the proper width of maxillary dentures in 4 racial groups. Method and Materials: One hundred sixty stone casts were obtained from impressions of the maxillary arch of white, black, mixed, and Asian subjects. The occlusal surfaces of the casts were photocopied and the images placed on a digitizer. The most anterior and posterior points of the papilla and cusp tips of the canines were digitized. Dentofacial Planner Plus software was used to calculate the distance from a line passing through the cusp tips of the canines to the center of the papilla, defined as the midpoint of the anterior and posterior points of the papilla. The selection error (in millimeters) due to the clinical application of the method of the incisive papilla was calculated and analyzed. Results: In all studied racial groups, there was no coincidence between the center of the incisive papilla and the canine line. The utilization of the center of the papilla would lead to the selection of wider artificial teeth. In 24.9% of the white, 19.3% of the mixed, 32.9% of the black, and 15.5% of the Asian populations, errors greater than 4 mm would be present with the utilization of the papilla. Conclusion: The method of the center of the incisive papilla is not accurate, but may aid in initial artificial teeth selection for the racial groups studied. (Quintessence Int 2008;39:841-845)

Search for production of single top quarks via tcg and tug flavor-changing-neutral-current couplings

We search for the production of single top quarks via flavor-changing-neutral-current couplings of a gluon to the top quark and a charm (c) or up (u) quark. We analyze 230 pb(-1) of lepton+jets data from p (p) over tilde collisions at a center of mass energy of 1.96 TeV collected by the D0 detector at the Fermilab Tevatron Collider. We observe no significant deviation from standard model predictions, and hence set upper limits on the anomalous coupling parameters kappa(c)(g)/Lambda and kappa(u)(g)/Lambda, where kappa(g) define the strength of tcg and tug couplings, and Lambda defines the scale of new physics. The limits at 95% C.L. are kappa(c)(g)/Lambda < 0.15 TeV-1 and kappa(u)(g)/Lambda < 0.037 TeV-1.

Relic abundance of mass-varying cold dark matter particles

In models of coupled dark energy and dark matter the mass of the dark matter particle depends on the cosmological evolution of the dark energy field. In this Letter we exemplify in a simple model the effects of this mass variation on the relic abundance of cold dark matter. (c) 2005 Elsevier B.V. All rights reserved.

Measurement of the t(t)over-bar production cross section in p(p)over-bar collisions at root s=1.96 TeV using kinematic characteristics of lepton plus jets events

We present a measurement of the top quark pair (t (t) over bar) production cross section (sigma(t (t) over bar)) in pp collisions at a center-of-mass energy of 1.96 TeV using 230 pb(-1) of data collected by the DO detector at the Fermilab Tevatron Collider. We select events with one charged lepton (electron or muon), large missing transverse energy, and at least four jets, and extract the t (t) over bar content of the sample based on the kinematic characteristics of the events. For a top quark mass of 175 GeV, we measure sigma(t (t) over bar) 6.7(-1.3)(+1.4)(stat)(-1.1)(+1.6)(syst) +/- 0.4(lumi) pb, in good agreement with the standard model prediction. (c) 2005 Elsevier B.V. All rights reserved.

Search for pair production of second generation scalar leptoquarks in p(p)over-bar collisions at root s-=1.96 TeV

We report on a search for the pair production of second generation scalar leptoquarks (LQ(2)) in p (p) over bar collisions at the center-of-mass energy, root s = 1.96 TeV, using data corresponding to an integrated luminosity of 294 19 pb(-1) recorded with the DO detector. No evidence for a leptoquark signal in the LQ(2)LQ(2) -> mu q mu q channel has been observed, and upper bounds on the product of cross section times branching fraction were set. This yields lower mass limits of m(LQ2) > 247 GeV/c(2) for beta = B(LQ(2) -> mu q) = 1 and m(LQ2) > 182 GeV/c(2) for beta = 1/2. Combining these limits with previous DO results, the lower limits on the mass of a second generation scalar leptoquark are m(LQ2) > 251 GeV/c(2) and m(LQ2) > 204 GeV/c(2) for beta = I and beta = 1/2, respectively. (c) 2006 Elsevier B.V. All rights reserved.

Measurement of the t(t)over-bar production cross section in p(p)over-bar collisions at root s=1.96 TeV using secondary vertex b tagging

We report a new measurement of the t (t) over bar production cross section in p (beta) over bar collisions at a center-of-mass energy of 1.96 TeV using events with one charged lepton (electron or muon), missing transverse energy, and jets. Using 425 pb(-1) of data collected using the D0 detector at the Fermilab Tevatron Collider, and enhancing the t (t) over bar content of the sample by tagging b jets with a secondary vertex tagging algorithm, the t (t) over bar production cross section is measured to be sigma(p (t) over bar -> t (t) over bar +X)=6.6 +/- 0.9(stat+syst) +/- 0.4(lum) pb. This cross section is the most precise D0 measurement to date for t (t) over bar production and is in good agreement with standard model expectations.

Measurement of the WW production cross section in p(p)over-bar collisions at root(s)over-bar=1.96 TeV

We present a measurement of the W boson pair-production cross section in p(p) over bar collisions at a center-of-mass energy of root s=1.96 TeV. The data, collected with the Run II D0 detector at Fermilab, correspond to an integrated luminosity of 224-252 pb(-1) depending on the final state (ee, e mu, or mu mu). We observe 25 candidates with a background expectation of 8.1 +/- 0.6(stat)+/- 0.6(syst)+/- 0.5(lum) events. The probability for an upward fluctuation of the background to produce the observed signal is 2.3x10(-7), equivalent to 5.2 standard deviations. The measurement yields a cross section of 13.8(-3.8)(+4.3)(stat)(-0.9)(+1.2)(syst)+/- 0.9(lum) pb, in agreement with predictions from the standard model.