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1.
Phys Rev Lett ; 132(6): 065104, 2024 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-38394572

RESUMO

As fusion experiments at the National Ignition Facility (NIF) approach and exceed breakeven, energy from the burning capsule is predicted to couple to the gold walls and reheat the hohlraum. On December 5, 2022, experiment N221204 exceeded target breakeven, historically achieving 3.15 MJ of fusion energy from 2.05 MJ of laser drive; for the first time, energy from the igniting capsule reheated the hohlraum beyond the peak laser-driven radiation temperature of 313 eV to a peak of 350 eV, in less than half a nanosecond. This reheating effect has now been unambiguously observed by the two independent Dante calorimeter systems across multiple experiments, and is shown to result from reheating of the remnant tungsten-doped ablator by the exploding core, which is heated by alpha deposition.

2.
Opt Lett ; 46(20): 5288-5291, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34653174

RESUMO

A major challenge in third harmonic generation and its converse, parametric down-conversion, is how to arrange phase matching between signals at ω and 3ω while maintaining a high nonlinear overlap. In this Letter, we present a design consisting of a nanostrand of glass with two hollow channels. The fundamental and third harmonic modal fields, enhanced in the region between the channels, have high nonlinear overlap, while the phase-matching wavelength can be coarse-tuned by gas pressure and fine-tuned by axial strain and mechanical twist, which, remarkably, have opposite effects. The ability to adjust the phase-matching condition may facilitate efficient generation of entangled photon triplets.

3.
HIV Med ; 20(8): 534-541, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31149766

RESUMO

OBJECTIVES: Adiponectin levels are inversely related to cardiovascular risk and are low in diabetics and obese persons. We examined the association between adiponectin concentration and HIV-associated lipodystrophy, which remains unclear. METHODS: The Study to Understand the Natural History of HIV/AIDS in the Era of Effective Therapy (SUN) was a prospective cohort study of HIV-infected adults conducted in four US cities. Lean body and fat masses were assessed using dual-energy X-ray absorptiometry scans. Using baseline data from 2004 to 2006, we defined lipodystrophy using a sex-specific fat mass ratio and performed cross-sectional analyses of associated risks using multivariable logistic regression. RESULTS: Among 440 male participants (median age 42 years; 68% non-Hispanic white; 88% prescribed combination antiretroviral therapy; median CD4 lymphocyte count 468 cells/µL; 76% with viral load < 400 HIV-1 RNA copies/mL; 5% diabetic; median body mass index 25 kg/m2 ), median concentrations of leptin and adiponectin were 3.04 ng/L [interquartile range (IQR) 1.77-5.43 ng/L] and 8005 µg/mL (IQR 4950-11 935 µg/mL), respectively. The prevalence of lipodystrophy was 14%. Lipodystrophy was significantly associated with increasing age [prevalence ratio (PR) 1.50; 95% confidence interval (CI) 1.10-2.06, per 10 years], adiponectin < 8005 µg/mL (PR 5.02; 95% CI 2.53-9.95), ever stavudine use (PR 2.26; 95% CI 1.36-3.75), CD4 cell count > 500 cells/µL (PR 2.59; 95% CI 1.46-4.61), viral load < 400 copies/mL (PR 3.98; 95% CI 1.25-12.6), highly sensitive C-reactive protein < 1.61 mg/L (PR 1.91; 95% CI 1.11-3.28) and smoking (PR 0.42; 95% CI 0.22-0.78). CONCLUSIONS: Among men in this HIV-infected cohort, the prevalence of lipodystrophy was similar to previous estimates for persons living with HIV, and was associated with lower adiponectin levels, potentially indicating increased cardiovascular disease risk.


Assuntos
Adiponectina/sangue , Antirretrovirais/uso terapêutico , Infecções por HIV/tratamento farmacológico , Lipodistrofia/diagnóstico por imagem , Absorciometria de Fóton , Tecido Adiposo/diagnóstico por imagem , Adulto , Estudos Transversais , Infecções por HIV/complicações , Infecções por HIV/metabolismo , Humanos , Lipodistrofia/epidemiologia , Lipodistrofia/metabolismo , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos Prospectivos , Estados Unidos/epidemiologia
4.
Bull Environ Contam Toxicol ; 101(1): 99-104, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29858623

RESUMO

In order to develop models that can predict the environmental behavior and effects of chemicals, reliable experimental data are needed. However, for anionic surfactants the number of ecotoxicity studies is still limited. The present study therefore aimed to determine the aquatic ecotoxicity of three classes of anionic surfactants. To this purpose we subjected daphnids (Daphnia magna) for 48 h to alkyl carboxylates (CxCO2-), alkyl sulfonates (CxSO3-), and alkyl sulfates (CxSO4-) with different carbon chain lengths (x). However, all surfactants with x > 11 showed less than 50% immobility at water solubility. Hence, EC50 values for only few surfactants could be gathered: C9CO2- (16 mg L-1), C11CO2- (0.8 mg L-1) and C11SO4- (13.5 mg L-1). Data from these compounds showed an increase in ecotoxicity with a factor 4.5 per addition of a hydrocarbon unit to the alkyl chain, and a factor 20 when replacing the sulfate head group by a carboxylate head group. Unfortunately, we could not test carboxylates with a broader variety of chain lengths because solubility limited the range of chain length that can be tested.


Assuntos
Tensoativos/toxicidade , Testes de Toxicidade , Poluentes Químicos da Água/toxicidade , Alcanossulfonatos/toxicidade , Animais , Ânions/toxicidade , Daphnia/efeitos dos fármacos , Dose Letal Mediana , Solubilidade
5.
Allergy ; 72(8): 1232-1242, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27926989

RESUMO

BACKGROUND: Eosinophilic esophagitis (EoE) is a chronic antigen-mediated clinicopathologic disease of the esophagus characterized by an eosinophil-predominant inflammatory infiltrate. A clinical hallmark is extensive tissue remodeling including basal zone hyperplasia, fibrosis, and angiogenesis. However, the cellular mechanisms responsible for these processes are not fully defined. We hypothesized that targeting granulocyte-macrophage colony-stimulating factor (GM-CSF; an agonist cytokine linked with eosinophil survival and activation) would be protective in a preclinical model of EoE. METHODS: Eosinophilic esophagitis-like esophageal inflammation was induced in the L2-IL5OXA EoE mouse model, and GM-CSF production was assessed by mRNA and protein analyses. Granulocyte-macrophage colony-stimulating factor-receptor-alpha expression patterns were examined by flow cytometric and immunofluorescence analysis. L2-IL5OXA EoE mice were treated with anti-GM-CSF neutralizing antibody or isotype control and assessed for histopathological indices of eosinophilia, epithelial hyperplasia, and angiogenesis by immunohistochemistry and RT-PCR. RESULTS: Significantly increased levels of esophageal GM-CSF expression was detected in the L2-IL5OXA mouse EoE model during active inflammation. Granulocyte-macrophage colony-stimulating factor-receptor-alpha was predominantly expressed on esophageal eosinophils during EoE, in addition to select cells within the lamina propria. Anti-GM-CSF neutralization in L2-IL5OXA EoE mice resulted in a significant diminution of epithelial eosinophilia in addition to basal cell hyperplasia and vascular remodeling. This treatment response was independent of effects on esophageal eosinophil maturation or activation. CONCLUSION: Granulocyte-macrophage colony-stimulating factor is a potential therapeutic target to reduce esophageal eosinophilia and remodeling.


Assuntos
Esofagite Eosinofílica/metabolismo , Esofagite Eosinofílica/patologia , Mucosa Esofágica/metabolismo , Mucosa Esofágica/patologia , Fator Estimulador de Colônias de Granulócitos e Macrófagos/metabolismo , Remodelação Vascular , Animais , Anticorpos Monoclonais/farmacologia , Linhagem Celular Transformada , Fatores Quimiotáticos de Eosinófilos/imunologia , Modelos Animais de Doenças , Esofagite Eosinofílica/genética , Esofagite Eosinofílica/imunologia , Eosinófilos/imunologia , Eosinófilos/metabolismo , Eosinófilos/patologia , Mucosa Esofágica/imunologia , Feminino , Expressão Gênica , Fator Estimulador de Colônias de Granulócitos e Macrófagos/antagonistas & inibidores , Fator Estimulador de Colônias de Granulócitos e Macrófagos/genética , Humanos , Masculino , Camundongos , Remodelação Vascular/efeitos dos fármacos , Remodelação Vascular/imunologia
6.
Dig Dis Sci ; 62(8): 1913-1922, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28551709

RESUMO

BACKGROUND: The clinical assessments of patients with gastrointestinal symptoms can be time-consuming, and the symptoms captured during the consultation may be influenced by a variety of patient and non-patient factors. To facilitate standardized symptom assessment in the routine clinical setting, we developed the Structured Assessment of Gastrointestinal Symptom (SAGIS) instrument to precisely characterize symptoms in a routine clinical setting. AIMS: We aimed to validate SAGIS including its reliability, construct and discriminant validity, and utility in the clinical setting. METHODS: Development of the SAGIS consisted of initial interviews with patients referred for the diagnostic work-up of digestive symptoms and relevant complaints identified. The final instrument consisted of 22 items as well as questions on extra intestinal symptoms and was given to 1120 consecutive patients attending a gastroenterology clinic randomly split into derivation (n = 596) and validation datasets (n = 551). Discriminant validity along with test-retest reliability was assessed. The time taken to perform a clinical assessment with and without the SAGIS was recorded along with doctor satisfaction with this tool. RESULTS: Exploratory factor analysis conducted on the derivation sample suggested five symptom constructs labeled as abdominal pain/discomfort (seven items), gastroesophageal reflux disease/regurgitation symptoms (four items), nausea/vomiting (three items), diarrhea/incontinence (five items), and difficult defecation and constipation (2 items). Confirmatory factor analysis conducted on the validation sample supported the initially developed five-factor measurement model ([Formula: see text], p < 0.0001, χ 2/df = 4.6, CFI = 0.90, TLI = 0.88, RMSEA = 0.08). All symptom groups demonstrated differentiation between disease groups. The SAGIS was shown to be reliable over time and resulted in a 38% reduction of the time required for clinical assessment. CONCLUSIONS: The SAGIS instrument has excellent psychometric properties and supports the clinical assessment of and symptom-based categorization of patients with a wide spectrum of gastrointestinal symptoms.


Assuntos
Gastroenteropatias/diagnóstico , Inquéritos e Questionários/normas , Avaliação de Sintomas/métodos , Análise Fatorial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Psicometria , Reprodutibilidade dos Testes , Avaliação de Sintomas/normas
7.
Clin Exp Immunol ; 185(2): 219-27, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27163159

RESUMO

The predisposition of preterm neonates to invasive infection is, as yet, incompletely understood. Regulatory T cells (Tregs ) are potential candidates for the ontogenetic control of immune activation and tissue damage in preterm infants. It was the aim of our study to characterize lymphocyte subsets and in particular CD4(+) CD25(+) forkhead box protein 3 (FoxP3)(+) Tregs in peripheral blood of well-phenotyped preterm infants (n = 117; 23 + 0 - 36 + 6 weeks of gestational age) in the first 3 days of life in comparison to term infants and adults. We demonstrated a negative correlation of Treg frequencies and gestational age. Tregs were increased in blood samples of preterm infants compared to term infants and adults. Notably, we found an increased Treg frequency in preterm infants with clinical early-onset sepsis while cause of preterm delivery, e.g. chorioamnionitis, did not affect Treg frequencies. Our data suggest that Tregs apparently play an important role in maintaining maternal-fetal tolerance, which turns into an increased sepsis risk after preterm delivery. Functional analyses are needed in order to elucidate whether Tregs have potential as future target for diagnostics and therapeutics.


Assuntos
Doenças do Prematuro/imunologia , Recém-Nascido Prematuro/imunologia , Sepse/imunologia , Linfócitos T Reguladores/imunologia , Adulto , Âmnio/microbiologia , Corioamnionite/imunologia , Feminino , Fatores de Transcrição Forkhead/sangue , Idade Gestacional , Humanos , Tolerância Imunológica , Lactente , Recém-Nascido , Subpopulações de Linfócitos/citologia , Subpopulações de Linfócitos/imunologia , Gravidez , Sepse/microbiologia
8.
Phys Rev Lett ; 112(10): 105003, 2014 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-24679301

RESUMO

Indirect drive experiments at the National Ignition Facility are designed to achieve fusion by imploding a fuel capsule with x rays from a laser-driven hohlraum. Previous experiments have been unable to determine whether a deficit in measured ablator implosion velocity relative to simulations is due to inadequate models of the hohlraum or ablator physics. ViewFactor experiments allow for the first time a direct measure of the x-ray drive from the capsule point of view. The experiments show a 15%-25% deficit relative to simulations and thus explain nearly all of the disagreement with the velocity data. In addition, the data from this open geometry provide much greater constraints on a predictive model of laser-driven hohlraum performance than the nominal ignition target.

9.
Phys Rev E ; 110(2-2): 025201, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39295028

RESUMO

A complete quasilinear model is derived for the electrostatic acceleration-driven lower hybrid drift instability in a uniform two-species low-beta plasma in which current is perpendicular to the background magnetic field. The model consists of coupled nonlinear velocity space diffusion equations for the volume-averaged ion and electron distribution functions. Each species' diffusion coefficient depends on a time-evolving spectral density of the electric-field energy per unit volume and a time-evolving dispersion relation. The dispersion relation is expressed analytically in integral form without the use of asymptotic limits and applies to arbitrary distribution functions, so long as they can be expressed as a function of one velocity coordinate, e.g., f(v_{y}) or f(v_{⊥}). The quasilinear model conserves energy and is complete in that it fully describes the evolution of the distribution functions, including resonant and nonresonant particle-wave interactions, while accounting for distribution-function-dependent mixed-complex frequencies. The quasilinear diffusion model is solved numerically and self-consistently using a Crank-Nicolson temporal discretization and a second-order finite-volume velocity-space discretization. Numerical solutions are compared to nonlinear fourth-order accurate continuum kinetic Vlasov-Poisson simulations. Evolution of electric-field energy, growth rates, distribution functions, and diffusion coefficients are shown to be in agreement with Vlasov simulations. The quasilinear model is shown to predict anomalous transport terms, like resistivity and heating, to within a factor of order unity. Discrepancies between the quasilinear model and Vlasov simulations are assessed and attributed primarily to lack of damping in the quasilinear description and to the use of unperturbed-orbit susceptibilities in the linear theory dispersion relation. The results illuminate the predictive accuracy of the quasilinear model, place approximate bounds on its validity, and provide much needed vetting of quasilinear theory's ability to predict the nonlinear state of a microturbulent plasma.

10.
Phys Rev Lett ; 110(8): 081801, 2013 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-23473129

RESUMO

Results are presented from a search for the pair production of third-generation scalar and vector leptoquarks, as well as for top squarks in R-parity-violating supersymmetric models. In either scenario, the new, heavy particle decays into a τ lepton and a b quark. The search is based on a data sample of pp collisions at sqrt[s] = 7 TeV, which is collected by the CMS detector at the LHC and corresponds to an integrated luminosity of 4.8 fb(-1). The number of observed events is found to be in agreement with the standard model prediction, and exclusion limits on mass parameters are obtained at the 95% confidence level. Vector leptoquarks with masses below 760 GeV are excluded and, if the branching fraction of the scalar leptoquark decay to a τ lepton and a b quark is assumed to be unity, third-generation scalar leptoquarks with masses below 525 GeV are ruled out. Top squarks with masses below 453 GeV are excluded for a typical benchmark scenario, and limits on the coupling between the top squark, τ lepton, and b quark, λ(333)(') are obtained. These results are the most stringent for these scenarios to date.


Assuntos
Interações de Partículas Elementares , Partículas Elementares , Modelos Teóricos , Física Nuclear/métodos
11.
Phys Rev Lett ; 110(8): 081802, 2013 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-23473130

RESUMO

The polarizations of the Υ(1S), Υ(2S), and Υ(3S) mesons are measured in proton-proton collisions at sqrt[s] = 7 TeV, using a data sample of Υ(nS) → µ +µ- decays collected by the CMS experiment, corresponding to an integrated luminosity of 4.9 fb(-1). The dimuon decay angular distributions are analyzed in three different polarization frames. The polarization parameters λ[symbol see text], λ(φ), and λ([symbol see text]φ), as well as the frame-invariant quantity λ, are presented as a function of the Υ(nS) transverse momentum between 10 and 50 GeV, in the rapidity ranges |y|<0.6 and 0.6<|y|<1.2. No evidence of large transverse or longitudinal polarizations is seen in the explored kinematic region.


Assuntos
Interações de Partículas Elementares , Mésons , Modelos Teóricos , Física Nuclear/métodos , Prótons
12.
Phys Rev Lett ; 111(8): 081802, 2013 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-24010428

RESUMO

An inclusive search is presented for new heavy particle pairs produced in √s=7 TeV proton-proton collisions at the LHC using 4.7±0.1 fb(-1) of integrated luminosity. The selected events are analyzed in the 2D razor space of M(R), an event-by-event indicator of the heavy particle mass scale, and R, a dimensionless variable related to the missing transverse energy. The third-generation sector is probed using the event heavy-flavor content. The search is sensitive to generic supersymmetry models with minimal assumptions about the superpartner decay chains. No excess is observed in the number of events beyond that predicted by the standard model. Exclusion limits are derived in the CMSSM framework as well as for simplified models. Within the CMSSM parameter space considered, gluino masses up to 800 GeV and squark masses up to 1.35 TeV are excluded at 95% confidence level depending on the model parameters. The direct production of pairs of top or bottom squarks is excluded for masses as high as 400 GeV.

13.
Phys Rev Lett ; 110(2): 022003, 2013 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-23383893

RESUMO

Evidence is presented for the associated production of a single top quark and W boson in pp collisions at sqrt[s]=7 TeV with the CMS experiment at the LHC. The analyzed data correspond to an integrated luminosity of 4.9 fb(-1). The measurement is performed using events with two leptons and a jet originated from a b quark. A multivariate analysis based on kinematic properties is utilized to separate the tt background from the signal. The observed signal has a significance of 4.0σ and corresponds to a cross section of 16(-4)(+5) pb, in agreement with the standard model expectation of 15.6±0.4(-1.2)(+1.0) pb.

14.
Phys Rev Lett ; 110(4): 042301, 2013 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-25166155

RESUMO

First measurements of the azimuthal anisotropy of neutral pions produced in Pb-Pb collisions at a center-of-mass energy of sqrt[s(NN)] = 2.76 TeV are presented. The amplitudes of the second Fourier component (v(2)) of the π(0) azimuthal distributions are extracted using an event-plane technique. The values of v(2) are studied as a function of the neutral pion transverse momentum (p(T)) for different classes of collision centrality in the kinematic range 1.6

15.
Clin Ther ; 45(1): 4-16, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36581528

RESUMO

PURPOSE: Premature infants, after anti-vascular endothelial growth factor injections for retinopathy of prematurity, have persistent peripheral avascular retina (PAR). PAR is ablated with laser; however, physiologic growth of the retinal vasculature in the long term has not been measured. The purposes of this study were to measure retinal vessel growth after treatment with intravitreal bevacizumab (IVB) for retinopathy of prematurity, using serial fluorescein angiography (FA), until age 3 years, and to assess the timing for providing laser ablation in PAR. METHODS: Data from an observational, longitudinal clinical study were collected. Angiographic images of eyes treated with IVB were included; imaging data from laser photocoagulation were excluded. All eyes underwent initial examination under general anesthesia with FA and photographic imaging. The retinal vessel length was measured from the temporal margin of the optic disc passing through the foveal center, and the lengths at subsequent FA were compared. To compare the changes in retinal vessel length over time in individual eyes, a paired-sample t test was performed. FINDINGS: FA images from 70 eyes (35 infants) treated with IVB were available. A total of 150 FA images were available for review; data from 125 images of good quality were used for analysis. The mean postmenstrual ages (PMAs) at first, second, third, and fourth FA were 66.2, 100.9, 135.1, and 180.7 weeks, respectively. The mean retinal vessel length was 14.177 mm at first FA and 13.199 mm at fourth FA (PMA range, 42...234 weeks). Retinal vascular lengths of individual eyes compared over time showed no statistically significant growth from the first FA to age 3 years. The changes in retinal vessel length from first to second FA were -0.117 ± 0.79 mm (p = 0.42; n = 30); from first to third FA, +0.060 ± 0.85 mm (p = 0.79; n = 15); and first to fourth FA, -0.404 ± 1.32 mm (p = 0.45; n = 7). IMPLICATIONS: Beyond 65 weeks' PMA, no meaningful retinal vascular growth occurred after IVB up to age 3 years, guiding the timing for physicians if laser photocoagulation is being considered. Future studies are needed to address retinal growth changes in the growing eyes of infants.


Assuntos
Inibidores da Angiogênese , Retinopatia da Prematuridade , Recém-Nascido , Lactente , Humanos , Pré-Escolar , Bevacizumab , Inibidores da Angiogênese/uso terapêutico , Retinopatia da Prematuridade/diagnóstico , Retinopatia da Prematuridade/tratamento farmacológico , Injeções Intravítreas , Estudos Retrospectivos , Recém-Nascido Prematuro
16.
Phys Rev Lett ; 108(11): 111801, 2012 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-22540461

RESUMO

A search for signatures of extra spatial dimensions in the diphoton invariant-mass spectrum has been performed with the CMS detector at the LHC. No excess of events above the standard model expectation is observed using a data sample collected in proton-proton collisions at √s=7 TeV corresponding to an integrated luminosity of 2.2 fb(-1). In the context of the large-extra-dimensions model, lower limits are set on the effective Planck scale in the range of 2.3-3.8 TeV at the 95% confidence level. These limits are the most restrictive bounds on virtual-graviton exchange to date. The most restrictive lower limits to date are also set on the mass of the first graviton excitation in the Randall-Sundrum model in the range of 0.86-1.84 TeV, for values of the associated coupling parameter between 0.01 and 0.10.

17.
Phys Rev Lett ; 108(11): 111804, 2012 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-22540464

RESUMO

A search for a Higgs boson in the four-lepton decay channel H→ZZ, with each Z boson decaying to an electron or muon pair, is reported. The search covers Higgs boson mass hypotheses in the range of 110100 GeV (with 13 below 160 GeV), while 67.1±6.0 (9.5±1.3) events are expected from background. The four-lepton mass distribution is consistent with the expectation of standard model background production of ZZ pairs. Upper limits at 95% confidence level exclude the standard model Higgs boson in the ranges of 134-158 GeV, 180-305 GeV, and 340-465 GeV. Small excesses of events are observed around masses of 119, 126, and 320 GeV, making the observed limits weaker than expected in the absence of a signal.

18.
Phys Rev Lett ; 109(12): 121801, 2012 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-23005937

RESUMO

The dimuon invariant mass spectrum is searched in the range between 5.5 and 14 GeV for a light pseudoscalar Higgs boson a, predicted in a number of new physics models, including the next-to-minimal supersymmetric standard model. The data sample used in the search corresponds to an integrated luminosity of 1.3 fb(-1) collected in pp collisions at √s = 7 TeV with the CMS detector at the LHC. No excess is observed above the background predictions and upper limits are set on the cross section times branching fraction σ × B(pp→a→µ(+)µ(-)) in the range of 1.5-7.5 pb. These results improve on existing bounds on the abb coupling for m(a) < m(Υ(1S)) and are the first significant limits for m(a) > m(Υ(3S)). Constraints on the supersymmetric parameter space are presented in the context of the next-to-minimal model.

19.
Phys Rev Lett ; 109(7): 071803, 2012 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-23006358

RESUMO

A search for new physics is performed in events with two same-sign isolated leptons, hadronic jets, and missing transverse energy in the final state. The analysis is based on a data sample corresponding to an integrated luminosity of 4.98 fb(-1) produced in pp collisions at a center-of-mass energy of 7 TeV collected by the CMS experiment at the LHC. This constitutes a factor of 140 increase in integrated luminosity over previously published results. The observed yields agree with the standard model predictions and thus no evidence for new physics is found. The observations are used to set upper limits on possible new physics contributions and to constrain supersymmetric models. To facilitate the interpretation of the data in a broader range of new physics scenarios, information on the event selection, detector response, and efficiencies is provided.

20.
Phys Rev Lett ; 108(25): 252002, 2012 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-23004588

RESUMO

The observation of a new b baryon via its strong decay into Ξ(b)(-) π(+) (plus charge conjugates) is reported. The measurement uses a data sample of pp collisions at sqrt[s] = 7 TeV collected by the CMS experiment at the LHC, corresponding to an integrated luminosity of 5.3 fb(-1). The known Ξ(b)(-) baryon is reconstructed via the decay chain Ξ(b)(-) → J/ψΞ(-) → µ(+) µ(-) Λ(0) π(-), with Λ(0) → pπ(-). A peak is observed in the distribution of the difference between the mass of the Ξ(b)(-) π(+) system and the sum of the masses of the Ξ(b)(-) and π(+), with a significance exceeding 5 standard deviations. The mass difference of the peak is 14.84 ± 0.74(stat) ± 0.28(syst) MeV. The new state most likely corresponds to the J(P) = 3/2(+) companion of the Ξ(b).

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