1,520 research outputs found
On classicalization in nonlinear sigma models
No full textAbstractWe consider the phenomenon of classicalization in nonlinear sigma models with both positive and negative target space curvature and with any number of derivatives. We find that the theories with only two derivatives exhibit a weak form of classicalization, and that the quantitative results depend on the sign of the curvature. Nonlinear sigma models with higher derivatives show a strong form of the phenomenon which is independent of the sign of curvature. We argue that weak classicalization may actually be equivalent to asymptotic safety, whereas strong classicalization seems to be a genuinely different phenomenon. We also discuss possible ambiguities in the definition of the classical limit
Measurement of the Xi(-)(b) and Omega(-)(b) baryon lifetimes
No full textUsing a data sample of pp collisions corresponding to an integrated luminosity of 3 fb−1, the Ξ−b and Ω−b baryons are reconstructed in the Ξ−b → J/ψΞ− and Ω−b → J/ψΩ− decay modes and their lifetimes measured to be
τ(Ξ−b) = 1.55+0.10−0.09 (stat) ± 0.03 (syst) ps,
τ(Ω−b) = 1.54+0.26−0.21 (stat) ± 0.05 (syst) ps.
These are the most precise determinations to date. Both measurements are in good agreement with previous experimental results and with theoretical predictions
Search for Lepton Number Violation at the LHCb. An Update for Majorana Neutrino Search with Like-Sign Di-Muons: Decay
No full textLepton number is conserved in the Standard Model, therefore, any evidence for its violation would indicate the existence of New Physics models. This paper presents selected searches of rare decays performed by the LHCb experiment. An update for the studies dedicated to on-shell Majorana neutrinos coupling to muons in the decay channel is also presented
Reconstitucion de foresta riberena en el municipio de Campo Tenente - PR - BR.
No full textTema 3.: Manejo, protección y conservación de bosques naturales. Resumo
Scale-dependent Planck mass and Higgs VEV from holography and functional renormalization
No full textAbstractWe compute the scale-dependence of the Planck mass and of the vacuum expectation value of the Higgs field using two very different renormalization group methods: a “holographic” procedure based on Einsteinʼs equations in five dimensions with matter confined to a 3-brane, and a “functional” procedure in four dimensions based on a Wilsonian momentum cutoff. Both calculations lead to very similar results, suggesting that the coupled theory approaches a non-trivial fixed point in the ultraviolet
Search for baryon and lepton number violation in heavy baryon decays and the background studies for exotic searches
No full textThe thesis describes searches for baryon and lepton number violation in decays. The study is performed in the \mbox{LHC\textit{b}} experiment using data sample corresponding to an integrated luminosity of of proton-proton collisions at the centre-of-mass energy of TeV TeV, collected in 2011 (2012), respectively. No statistically significant signal of the decays in question has been found. As a result, the upper limits have been set: and at the confidence level. The second part of the thesis presents the background studies for exotic searches. The measurement of and production cross-sections with hadron inclusive final states has been performed with data collected by the \mbox{LHC\textit{b}} experiment in 2010 in proton-proton collisions at the centre-of-mass energy of TeV. The author of this thesis has prepared the interface to the Next-To-Leading-Order POWHEG simulation framework into the \lhcb software chain. All the kinematic characteristics of the hadron production in proton-proton collisions have been studied. The resulting angular and momentum correlations indicate a possible contribution from other mechanisms of LHCb production than the , mainly the
Estoque de carbono e fluxo de gases de efeito estufa em florestas de pinus e mata nativa.
No full textResumo
Production measurements at LHCb
No full textThe detector, with its excellent momentum resolution and flexible trigger strategy, is ideally suited for measuring heavy quark and quarkonia production properties. In addition, the new system of forward shower counters installed upstream and downstream has begun to be used, therefore the experiment is being suited to measure central exclusive production. The measurements of inclusive and differential cross-sections of the production of resonance and pairs, as well bottom quarks and boson, based on Run 2 datasets are summarized. Finally, results on the prompt production of open charm hadrons and the exclusive production of charmonium are discussed
Efeito dos resíduos de pinus e da adubação sobre os fluxos de gases de efeito estufa do solo.
No full textA manutenção de resíduos florestais da colheita contribui com a ciclagem de nutrientes. A retirada destes resíduos exige a reposição de nutrientes pela fertilização. Essas práticas têm efeito direto na sustentabilidade dos sítios florestais e podem afetar também a capacidade das florestas em contribuir com a mitigação da emissão de gases de efeito estufa (GEE). O objetivo desse estudo foi mensurar o impacto do manejo dos resíduos da colheita sobre os fluxos de GEE e umidade do solo e o crescimento das plantas. Em junho de 2019 foi implantado experimento combinando: resíduo e fertilizante (R+F); resíduo sem fertilizante (R-F); sem resíduo e com fertilizante (sR+F) e sem resíduo e sem fertilizante (sR-F), na implantação da nova floresta de Pinus taeda. Cada parcela tem 70 plantas espaçadas de 2 m x 3 m. A adubação foi dividida em duas parcelas iguais aplicadas em 04/12/2019 e 04/03/2020, com 25 kg ha-1, 60 kg ha-1 e 60 kg ha-1 de N, P2O5 e K2O. Para monitorar o fluxo dos GEE, em cada parcela foram instalados na superfície do solo três bases para a coleta de amostras de ar. Para as análises da concentração de dióxido de carbono (CO2), metano (CH4) e óxido nitroso (N2O) utilizou-se o analisador automático Picarro G2508. A umidade do solo foi determinada em amostras coletadas com trado calador, na camada de 0-5cm. Tanto na presença como na ausência do resíduo, a adubação promoveu aumento da emissão de N2O (165% e 300%) e CH4 (45% e 200%), respectivamente. O aumento foi maior na ausência de resíduos da colheita, possivelmente por que o solo fica mais exposto, levando a uma maior temperatura do solo (+1 ᵒC) e desencadeando maior atividade microbiana. Os fluxos de CO2 não mostraram uma tendência definida. A ausência dos resíduos também refletiu na umidade do solo, que foi 2% menor nos tratamentos sem resíduos. A taxa de crescimento do pinus, aos seis meses, não evidenciou diferenças marcantes entre os tratamentos, apenas mostrou uma tendência de maior crescimento no tratamento sR+F. Considerando os resultados até o momento, a presença de resíduos contribuiu com a mitigação da emissão de GEE, maior disponibilidade de água no sistema, sem efeitos diretos no crescimento das planta
A study of CP violation in B±→DK±B±→DK± and B±→Dπ±B±→Dπ± decays with D→KS0K±π∓ final states
No full textA first study of CP violation in the decay modes B± → [K0S K ±π∓]Dh± and B± → [K0S K ∓π±]Dh±, where h labels a K or π meson and D labels a D0 or D0 meson, is performed. The analysis uses the LHCb data set collected in pp collisions, corresponding to an integrated luminosity of 3 fb−1. The analysis is sensitive to the CP-violating CKM phase γ through seven observables: one charge asymmetry in each of the four modes and three ratios of the charge-integrated yields. The results are consistent with measurements of γ using other decay modes
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