80 research outputs found

    Perioperative echocardiography-guided hemodynamic therapy in high-risk patients:a practical expert approach of hemodynamically focused echocardiography

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    The number of high-risk patients undergoing surgery is growing. To maintain adequate hemodynamic functioning as well as oxygen delivery to the vital organs (DO2) amongst this patient population, a rapid assessment of cardiac functioning is essential for the anesthesiologist. Pinpointing any underlying cardiovascular pathophysiology can be decisive to guide interventions in the intraoperative setting. Various techniques are available to monitor the hemodynamic status of the patient, however due to intrinsic limitations, many of these methods may not be able to directly identify the underlying cause of cardiovascular impairment. Hemodynamic focused echocardiography, as a rapid diagnostic method, offers an excellent opportunity to examine signs of filling impairment, cardiac preload, myocardial contractility and the function of the heart valves. We thus propose a 6-step-echocardiographic approach to assess high-risk patients in order to improve and maintain perioperative DO2. The summary of all echocardiographic based findings allows a differentiated assessment of the patient's cardiovascular function and can thus help guide a (patho)physiological-orientated and individualized hemodynamic therapy

    Observation of B(s)0→J/ψppÂŻ decays and precision measurements of the B(s)0 masses

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    The first observation of the decays B 0 ( s ) → J / ψ p ÂŻ p is reported, using proton-proton collision data corresponding to an integrated luminosity of 5.2     fb − 1 , collected with the LHCb detector. These decays are suppressed due to limited available phase space, as well as due to Okubo-Zweig-Iizuka or Cabibbo suppression. The measured branching fractions are B ( B 0 → J / ψ p ÂŻ p ) = [ 4.51 ± 0.40 ( stat ) ± 0.44 ( syst ) ] × 10 − 7 , B ( B 0 s → J / ψ p ÂŻ p ) = [ 3.58 ± 0.19 ( stat ) ± 0.39 ( syst ) ] × 10 − 6 . For the B 0 s meson, the result is much higher than the expected value of O ( 10 − 9 ) . The small available phase space in these decays also allows for the most precise single measurement of both the B 0 mass as 5279.74 ± 0.30 ( stat ) ± 0.10 ( syst )     MeV and the B 0 s mass as 5366.85 ± 0.19 ( stat ) ± 0.13 ( syst )     MeV

    Observation of the decay Λ <sub>b</sub> <sup>0</sup>  → ψ(2S)pπ<sup>−</sup>

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    International audienceThe Cabibbo-suppressed decay Λb0_{b}^{0}  → ψ(2S)pπ−^{−} is observed for the first time using a data sample collected by the LHCb experiment in proton-proton collisions corresponding to 1.0, 2.0 and 1.9 fb−1^{−1} of integrated luminosity at centre-of-mass energies of 7, 8 and 13 TeV, respectively. The ψ(2S) mesons are reconstructed in the ÎŒ+^{+}Ό−^{−} final state. The branching fraction with respect to that of the Λb0_{b}^{0}  → ψ(2S)pK−^{−} decay mode is measured to b

    Search for CP violation in Λb0→pK− and Λb0→pπ− decays

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    A search for CP violation in Λb0→pK− and Λb0→pπ− decays is presented using a sample of pp collisions collected with the LHCb detector and corresponding to an integrated luminosity of 3.0fb−1. The CP -violating asymmetries are measured to be ACPpK−=−0.020±0.013±0.019 and ACPpπ−=−0.035±0.017±0.020, and their difference ACPpK−−ACPpπ−=0.014±0.022±0.010, where the first uncertainties are statistical and the second systematic. These are the most precise measurements of such asymmetries to date

    Evidence for an nc(1S)ff- resonance in B0 yc(1S)K+ decays

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    A Dalitz plot analysis of B0→ηc(1S)K+π- decays is performed using data samples of pp collisions collected with the LHCb detector at centre-of-mass energies of s=7,8 and 13TeV , corresponding to a total integrated luminosity of 4.7fb-1 . A satisfactory description of the data is obtained when including a contribution representing an exotic ηc(1S)π- resonant state. The significance of this exotic resonance is more than three standard deviations, while its mass and width are 4096±20-22+18MeV and 152±58-35+60MeV , respectively. The spin-parity assignments JP=0+ and JP=1- are both consistent with the data. In addition, the first measurement of the B0→ηc(1S)K+π- branching fraction is performed and gives B(B0→ηc(1S)K+π-)=(5.73±0.24±0.13±0.66)×10-4, where the first uncertainty is statistical, the second systematic, and the third is due to limited knowledge of external branching fractions

    Measurement of the electron reconstruction efficiency at LHCb

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    The single electron track-reconstruction efficiency is calibrated using a sample corresponding to 1.3 fb−1 of pp collision data recorded with the LHCb detector in 2017. This measurement exploits B+→ J/ψ(e+e−)K+ decays, where one of the electrons is fully reconstructed and paired with the kaon, while the other electron is reconstructed using only the information of the vertex detector. Despite this partial reconstruction, kinematic and geometric constraints allow the B meson mass to be reconstructed and the signal to be well separated from backgrounds. This in turn allows the electron reconstruction efficiency to be measured by matching the partial track segment found in the vertex detector to tracks found by LHCb's regular reconstruction algorithms. The agreement between data and simulation is evaluated, and corrections are derived for simulated electrons in bins of kinematics. These correction factors allow LHCb to measure branching fractions involving single electrons with a systematic uncertainty below 1%

    Amplitude analysis of the B0 (s)! K0K0 decays and measurement of the branching fraction of the B0! K0K0 decay

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    The B0→K∗0K‟∗0B^0 \to K^{*0} \overline{K}^{*0} and Bs0→K∗0K‟∗0B^0_s \to K^{*0} \overline{K}^{*0} decays are studied using proton-proton collision data corresponding to an integrated luminosity of 3fb−1^{-1}. An untagged and time-integrated amplitude analysis of B(s)0→(K+π−)(K−π+)B^0_{(s)} \to (K^+\pi^-)(K^-\pi^+) decays in two-body invariant mass regions of 150 MeV/c2/c^2 around the K∗0K^{*0} mass is performed. A stronger longitudinal polarisation fraction in the B0→K∗0K‟∗0{B^0 \to K^{*0} \overline{K}^{*0}} decay, fL=0.724±0.051 (stat)±0.016 (syst){f_L = 0.724 \pm 0.051 \,({\rm stat}) \pm 0.016 \,({\rm syst})}, is observed as compared to fL=0.240±0.031 (stat)±0.025 (syst){f_L = 0.240 \pm 0.031 \,({\rm stat}) \pm 0.025 \,({\rm syst})} in the Bs0→K∗0K‟∗0{B^0_s\to K^{*0} \overline{K}^{*0}} decay. The ratio of branching fractions of the two decays is measured and used to determine B(B0→K∗0K‟∗0)=(8.0±0.9 (stat)±0.4 (syst))×10−7\mathcal{B}(B^0 \to K^{*0} \overline{K}^{*0}) = (8.0 \pm 0.9 \,({\rm stat}) \pm 0.4 \,({\rm syst})) \times 10^{-7}.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2019-004.html (LHCb public pages

    Search for Lepton-Universality Violation in B^{+}→K^{+}ℓ^{+}ℓ^{-} Decays.

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    A measurement of the ratio of branching fractions of the decays B^{+}→K^{+}ÎŒ^{+}ÎŒ^{-} and B^{+}→K^{+}e^{+}e^{-} is presented. The proton-proton collision data used correspond to an integrated luminosity of 5.0  fb^{-1} recorded with the LHCb experiment at center-of-mass energies of 7, 8, and 13 TeV. For the dilepton mass-squared range 1.1<q^{2}<6.0  GeV^{2}/c^{4} the ratio of branching fractions is measured to be R_{K}=0.846_{-0.054}^{+0.060}_{-0.014}^{+0.016}, where the first uncertainty is statistical and the second systematic. This is the most precise measurement of R_{K} to date and is compatible with the standard model at the level of 2.5 standard deviations

    Amplitude analysis of B-s(0) -> K-S(0) K-+/-pi(-/+) decays

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    The first untagged decay-time-integrated amplitude analysis of Bs0→KS0K±π∓B^{0}_{s} \rightarrow K^{0}_{\textrm{S}} K^{\pm}\pi^{\mp} decays is performed using a sample corresponding to 3.0 3.0\,fb−1^{-1} of pppp collision data recorded with the LHCb detector during 2011 and 2012. The data are described with an amplitude model that contains contributions from the intermediate resonances K∗(892)0,+K^{*}(892)^{0,+}, K2∗(1430)0,+K^*_2(1430)^{0,+} and K0∗(1430)0,+K^*_0(1430)^{0,+}, and their charge conjugates. Measurements of the branching fractions of the decay modes Bs0→K∗(892)±K∓B^{0}_{s} \rightarrow K^{*}(892)^{\pm}K^{\mp} and Bs0→K∗(892)0K‟0,K‟∗(892)0K0B^{0}_{s} \rightarrow K^{*}(892)^{0}\kern 0.2em\overline{\kern -0.2em K}{}^{0}, \kern 0.2em\overline{\kern -0.2em K}{}^{*}(892)^{0}K^{0} are in agreement with, and more precise than, previous results. The decays Bs0→K0∗(1430)±K∓B^{0}_{s} \rightarrow K^*_0(1430)^{\pm} K^{\mp} and Bs0→K0∗(1430)0K‟0,K‟0∗(1430)0K0B^{0}_{s} \rightarrow K^{*}_{0}(1430)^{0}\kern 0.2em\overline{\kern -0.2em K}{}^{0}, \kern 0.2em\overline{\kern -0.2em K}{}^{*}_{0}(1430)^{0}K^{0} are observed for the first time, each with significance over 10 standard deviations.Comment: 27 pages, 14 figures. All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2018-045.htm

    Measurement of CPCP asymmetry in Bs0→Ds∓K±B_s^0 \to D_s^{\mp} K^{\pm} decays

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    We report the measurements of the CPCP-violating parameters in Bs0→Ds∓K±B_s^0 \to D_s^{\mp} K^{\pm} decays observed in pppp collisions, using a data set corresponding to an integrated luminosity of 3.0 fb−13.0\,\text{fb}^{-1} recorded with the LHCb detector. We measure Cf=0.73±0.14±0.05C_f = 0.73 \pm 0.14 \pm 0.05, AfΔΓ=0.39±0.28±0.15A^{\Delta \Gamma}_f = 0.39 \pm 0.28 \pm 0.15, Af‟ΔΓ=0.31±0.28±0.15A^{\Delta \Gamma}_{\overline{f}} = 0.31 \pm 0.28 \pm 0.15, Sf=−0.52±0.20±0.07S_f = -0.52 \pm 0.20 \pm 0.07, Sf‟=−0.49±0.20±0.07S_{\overline{f}} = -0.49 \pm 0.20 \pm 0.07, where the uncertainties are statistical and systematic, respectively. These parameters are used together with the world-average value of the Bs0B_s^0 mixing phase, −2ÎČs-2\beta_s, to obtain a measurement of the CKM angle Îł\gamma from Bs0→Ds∓K±B_s^0 \to D_s^{\mp} K^{\pm} decays, yielding \gamma = (128\,_{-22}^{+17})^\circ modulo 180∘180^\circ, where the uncertainty contains both statistical and systematic contributions. This corresponds to 3.8 σ3.8\,\sigma evidence for CPCP violation in the interference between decay and decay after mixing.We report the measurements of the CP -violating parameters in Bs0_{s}^{0}  → Ds∓_{s}^{∓} K±^{±} decays observed in pp collisions, using a data set corresponding to an integrated luminosity of 3.0 fb−1^{−1} recorded with the LHCb detector. We measure Cf_{f} = 0.73 ± 0.14 ± 0.05, AfΔΓ_{f}^{ΔΓ}  = 0.39 ± 0.28 ± 0.15, Af‟ΔΓ=0.31±0.28±0.15 {A}_{\overline{f}}^{\varDelta \varGamma }=0.31\pm 0.28\pm 0.15 , Sf_{f} = −0.52 ± 0.20 ± 0.07, Sf‟=−0.49±0.20±0.07 {S}_{\overline{f}}=-0.49\pm 0.20\pm 0.07 , where the uncertainties are statistical and systematic, respectively. These parameters are used together with the world-average value of the Bs0_{s}^{0} mixing phase, −2ÎČs_{s} , to obtain a measurement of the CKM angle Îł from Bs0_{s}^{0}  → Ds∓_{s}^{∓} K±^{±} decays, yielding γ = (128− 22+ 17_{− 22}^{+ 17} )° modulo 180°, where the uncertainty contains both statistical and systematic contributions. This corresponds to 3.8 σ evidence for CP violation in the interference between decay and decay after mixing
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