Measurement of the J/ψ pair production cross-section in pp collisions at s=13 \sqrt{s}=13 TeV

The production cross-section of J/ψ pairs is measured using a data sample of pp collisions collected by the LHCb experiment at a centre-of-mass energy of $\sqrt{s}=13$ TeV, corresponding to an integrated luminosity of 279 ±11 pb$^{−1}$. The measurement is performed for J/ψ mesons with a transverse momentum of less than 10 GeV/c in the rapidity range 2.0 < y < 4.5. The production cross-section is measured to be 15.2 ± 1.0 ± 0.9 nb. The first uncertainty is statistical, and the second is systematic. The differential cross-sections as functions of several kinematic variables of the J/ψ pair are measured and compared to theoretical predictions.The production cross-section of $J/\psi$ pairs is measured using a data sample of $pp$ collisions collected by the LHCb experiment at a centre-of-mass energy of $\sqrt{s} = 13 \,{\mathrm{TeV}}$, corresponding to an integrated luminosity of $279 \pm 11 \,{\mathrm{pb^{-1}}}$. The measurement is performed for $J/\psi$ mesons with a transverse momentum of less than $10 \,{\mathrm{GeV}}/c$ in the rapidity range $2.0<y<4.5$. The production cross-section is measured to be $15.2 \pm 1.0 \pm 0.9 \,{\mathrm{nb}}$. The first uncertainty is statistical, and the second is systematic. The differential cross-sections as functions of several kinematic variables of the $J/\psi$ pair are measured and compared to theoretical predictions

Measurement of the B0s→μ+μ− Branching Fraction and Effective Lifetime and Search for B0→μ+μ− Decays

A search for the rare decays Bs0→μ+μ- and B0→μ+μ- is performed at the LHCb experiment using data collected in pp collisions corresponding to a total integrated luminosity of 4.4  fb-1. An excess of Bs0→μ+μ- decays is observed with a significance of 7.8 standard deviations, representing the first observation of this decay in a single experiment. The branching fraction is measured to be B(Bs0→μ+μ-)=(3.0±0.6-0.2+0.3)×10-9, where the first uncertainty is statistical and the second systematic. The first measurement of the Bs0→μ+μ- effective lifetime, τ(Bs0→μ+μ-)=2.04±0.44±0.05  ps, is reported. No significant excess of B0→μ+μ- decays is found, and a 95% confidence level upper limit, B(B0→μ+μ-)<3.4×10-10, is determined. All results are in agreement with the standard model expectations.A search for the rare decays $B^0_s\to\mu^+\mu^-$ and $B^0\to\mu^+\mu^-$ is performed at the LHCb experiment using data collected in $pp$ collisions corresponding to a total integrated luminosity of 4.4 fb$^{-1}$. An excess of $B^0_s\to\mu^+\mu^-$ decays is observed with a significance of 7.8 standard deviations, representing the first observation of this decay in a single experiment. The branching fraction is measured to be ${\cal B}(B^0_s\to\mu^+\mu^-)=\left(3.0\pm 0.6^{+0.3}_{-0.2}\right)\times 10^{-9}$, where the first uncertainty is statistical and the second systematic. The first measurement of the $B^0_s\to\mu^+\mu^-$ effective lifetime, $\tau(B^0_s\to\mu^+\mu^-)=2.04\pm 0.44\pm 0.05$ ps, is reported. No significant excess of $B^0\to\mu^+\mu^-$ decays is found and a 95 % confidence level upper limit, ${\cal B}(B^0\to\mu^+\mu^-)<3.4\times 10^{-10}$, is determined. All results are in agreement with the Standard Model expectations

Fisioterapia respiratória no pré e pós-operatório de cirurgia de revascularização do miocárdio Respiratory physiotherapy in the pre and postoperative myocardial revascularization surgery

As doenças cardiovasculares estão entre as principais causas de morte no mundo desenvolvido, e sua ocorrência tem aumentado de forma epidêmica nos países em desenvolvimento. Apesar das inúmeras alternativas para o tratamento da doença arterial coronariana; a cirurgia de revascularização do miocárdio é uma opção com indicações precisas de médio e longo prazo, com bons resultados. Pode proporcionar a remissão dos sintomas de angina e, também, contribui para o aumento da expectativa e melhora da qualidade de vida. Pacientes submetidos à cirurgia de revascularização do miocárdio desenvolvem, em sua maioria, disfunção pulmonar pós-operatória com redução importante dos volumes pulmonares, prejuízos na mecânica respiratória, diminuição na complacência pulmonar e aumento do trabalho respiratório. A redução dos volumes e capacidades pulmonares contribui para alterações nas trocas gasosas, resultando em hipoxemia e diminuição na capacidade de difusão. Dentro deste contexto, a Fisioterapia tem sido cada vez mais requisitada tanto no pré quanto no pós-operatório deste tipo de cirurgia. Este estudo teve como objetivo atualizar os conhecimentos em relação à atuação da Fisioterapia respiratória no pré e pós-operatório de cirurgia de revascularização do miocárdio, com ênfase na prevenção de complicações pulmonares. A Fisioterapia no período pré-operatório atua por meio de inúmeras técnicas, entre as quais, pode-se destacar: a espirometria de incentivo, exercícios de respiração profunda, tosse, treinamento muscular inspiratório, deambulação precoce e orientações fisioterapêuticas. Enquanto que no pós-operatório, tem como objetivo o tratamento das complicações pulmonares instaladas, realizado por meio de manobras fisioterapêuticas e dispositivos respiratórios não invasivos, visando melhorar a mecânica respiratória, a reexpansão pulmonar e a higiene brônquica. A Fisioterapia respiratória é parte integrante na gestão dos cuidados do paciente cardiopata, tanto no pré quanto no pós-operatório, pois contribui significativamente para um melhor prognóstico desses pacientes por meio de técnicas específicas.<br>The cardiovascular diseases are among the main death causes in the developed world. They have been increasing epidemically in the developing countries. In spite of several alternatives for the treatment of the coronary artery disease; the surgery of the myocardial revascularization is an option with proper indications of medium and long-term with good results. It provides the remission of the angina symptoms contributing to the increase of the expectation and improvement of the life quality. Most of patients undergoing myocardial revascularization surgery develop postoperative lung dysfunction with important reduction of the lung volumes, damages in the respiratory mechanism, decrease in the lung indulgence and increase of the respiratory work. The reduction of volumes and lung capacities can contribute to alterations in the gas exchanges, resulting in hypoxemia and decrease in the diffusion capacity. Taking this into account, the Physiotherapy has been requested more and more to perform in the pre as well as in the postoperative period of this surgery. This study aimed at updating the knowledge regarding the respiratory physiotherapy performance in the pre and postoperative period of the myocardial revascularization surgery enhancing the prevention of lung complications. The Physiotherapy uses several techniques in the preoperative period; such as: the incentive spirometry, exercises of deep breathing, cough, inspiratory muscle training, earlier ambulation and physiotherapeutic orientations. While in the postoperative period, the objective is the treatment after lung complications took place, performed by means of physiotherapeutic maneuvers and noninvasive respiratory devices, aiming at improving the respiratory mechanism, the lung reexpansion and the bronchial hygiene. Respiratory physiotherapy is an integral part in the care management of the patient with cardiopathy, either in the pre or in the postoperative period, since it contributes significantly to a better prognosis of these patients with the use of specific techniques

Hipermobilidade articular em pacientes com prolapso da valva mitral Hipermovilidad articular en pacientes con prolapso de la válvula mitral Joint hypermobility in patients with mitral valve prolapse

Estudos sobre hipermobilidade têm despertado grande interesse, nas últimas décadas, por estarem associados a disfunções músculo-esqueléticas, bem como a anormalidades em vários sistemas orgânicos - como, por exemplo, o prolapso da valva mitral. Neste contexto, buscou-se agrupar e atualizar os conhecimentos da relação entre a hipermobilidade articular e o prolapso da valva mitral. Segundo a literatura, estudos mostram que alterações genéticas na composição do colágeno parecem ser a principal causa desta relação.<br>Studies on hypermobility have aroused great interest in the last decades, as they are associated to musculoskeletal disorders, as well as abnormalities in several organic systems, such as the mitral valve prolapse. Therefore, in this study, data on the association between joint hypermobility and the mitral valve prolapse were investigated and reviewed. Studies in the literature have shown that genetic alterations in the collagen composition seem to be the main cause of this association

Observation of a new Ξb−\Xi_b^- resonance

International audienceFrom samples of pp collision data collected by the LHCb experiment at s=7, 8 and 13 TeV, corresponding to integrated luminosities of 1.0, 2.0 and 1.5  fb-1, respectively, a peak in both the Λb0K- and Ξb0π- invariant mass spectra is observed. In the quark model, radially and orbitally excited Ξb- resonances with quark content bds are expected. Referring to this peak as Ξb(6227)-, the mass and natural width are measured to be mΞb(6227)-=6226.9±2.0±0.3±0.2  MeV/c2 and ΓΞb(6227)-=18.1±5.4±1.8  MeV/c2, where the first uncertainty is statistical, the second is systematic, and the third, on mΞb(6227)-, is due to the knowledge of the Λb0 baryon mass. Relative production rates of the Ξb(6227)-→Λb0K- and Ξb(6227)-→Ξb0π- decays are also reported

Observation of the decay Bs0→D‾0K+K−B_s^0 \to \overline{D}^0 K^+ K^-

International audienceThe first observation of the Bs0→D¯0K+K- decay is reported, together with the most precise branching fraction measurement of the mode B0→D¯0K+K-. The results are obtained from an analysis of pp collision data corresponding to an integrated luminosity of 3.0  fb-1. The data were collected with the LHCb detector at center-of-mass energies of 7 and 8 TeV. The branching fraction of the B0→D¯0K+K- decay is measured relative to that of the decay B0→D¯0π+π- to be B(B0→D¯0K+K-)B(B0→D¯0π+π-)=(6.9±0.4±0.3)%, where the first uncertainty is statistical and the second is systematic. The measured branching fraction of the Bs0→D¯0K+K- decay mode relative to that of the corresponding B0 decay is B(Bs0→D¯0K+K-)B(B0→D¯0K+K-)=(93.0±8.9±6.9)%. Using the known branching fraction of B0→D¯0π+π-, the values of B(B0→D¯0K+K-)=(6.1±0.4±0.3±0.3)×10-5 and B(Bs0→D¯0K+K-)=(5.7±0.5±0.4±0.5)×10-5 are obtained, where the third uncertainties arise from the branching fraction of the decay modes B0→D¯0π+π- and B0→D¯0K+K-, respectively

Observation of Bs0→D‾∗0ϕB_s^0 \to \overline{D}^{*0} \phi and search for B0→D‾0ϕB^0 \to \overline{D}^0 \phi decays

International audienceThe first observation of the Bs0→D¯*0ϕ decay is reported, with a significance of more than seven standard deviations, from an analysis of pp collision data corresponding to an integrated luminosity of 3  fb-1, collected with the LHCb detector at center-of-mass energies of 7 and 8 TeV. The branching fraction is measured relative to that of the topologically similar decay B0→D¯0π+π- and is found to be B(Bs0→D¯*0ϕ)=(3.7±0.5±0.3±0.2)×10-5, where the first uncertainty is statistical, the second systematic, and the third from the branching fraction of the B0→D¯0π+π- decay. The fraction of longitudinal polarization in this decay is measured to be fL=(73±15±4)%. The most precise determination of the branching fraction for the Bs0→D¯0ϕ decay is also obtained, B(Bs0→D¯0ϕ)=(3.0±0.3±0.2±0.2)×10-5. An upper limit, B(B0→D¯0ϕ)<2.0 (2.3)×10-6 at 90% (95%) confidence level is set. A constraint on the ω-ϕ mixing angle δ is set at |δ|<5.2° (5.5°) at 90% (95%) confidence level

Observation of Bs0→Dˉ∗0ϕB_s^0 \to \bar{D}^{*0} \phi and search for B0→Dˉ0ϕB^0 \to \bar{D}^0 \phi decays

The first observation of the $B^0_s → \bar{D}^{*0}ϕ$ decay is reported, with a significance of more than seven standard deviations, from an analysis of pp collision data corresponding to an integrated luminosity of 3  fb$^{−1}$, collected with the LHCb detector at center-of-mass energies of 7 and 8 TeV. The branching fraction is measured relative to that of the topologically similar decay $B^0 → \bar{D}^0 π^+ π^−$ and is found to be $\mathcal{B}(B^0_s → \bar{D}^{*0}ϕ)=(3.7±0.5±0.3±0.2) × 10^{−5}$, where the first uncertainty is statistical, the second systematic, and the third from the branching fraction of the $B^0 → \bar{D}^0 π^+ π^−$ decay. The fraction of longitudinal polarization in this decay is measured to be $f_L = (73±15±4)\%$. The most precise determination of the branching fraction for the $B^0_s → \bar{D}^{0}ϕ$ decay is also obtained, $\mathcal{B}(B^0_s → \bar{D}^0 ϕ)=(3.0±0.3±0.2±0.2) × 10^{−5}$. An upper limit,$\mathcal{B}(B^0 → \bar{D}^0 ϕ) < 2.0 (2.3) × 10^{−6}$ at 90% (95%) confidence level is set. A constraint on the $ω−ϕ$ mixing angle $δ$ is set at $|δ| < 5.2°$ (5.5°) at 90% (95%) confidence level