24 research outputs found

    Assessment of Prognostic Factors for Reconstruction of the Upper Third of the Ureter with A Tubularized Pelvis Flap

    Full text link
    Ureteral plastic with a tubularized pelvic flap is a rare option of ureteral reconstruction. We present the assessment of the factors that are important for predicting the success of this operation.The aim. The purpose of the study was to assess the factors that are important in predicting the success of reconstruction of the upper third of the ureter with a tubularized pelvis flap.Material and methods. The study included 73 patients who were divided into 2 groups. The first group had extended strictures of the upper third of the ureter (n=14 / 19.2 %), and the second group had pathology of the ureteropelvic junction associated with ureterovascular conflict (n=59 / 80.8 %).Results. The length of the pelvic flap varied from 2.5 to 10.0 cm and reached an average of 3.9 cm. Early postoperative complications (Clavien-Dindo gradation <3) were observed in 14 (9.2 %) patients out of 73, and dominated in the first group. The total number of positive long-term results (good + satisfactory) was 97.3 %. Two poor results were reported only in patients of the first group with prolonged recurrent strictures. A significant factor in the prognosis of complications was the secondary nature of the operation (p <0.004). The factors of the long-term results prognosis were the performance of dismembered tubularized flap pyeloplasty due to the extended strictures of the upper third of the ureter, and the duration of the operation more than 120 minutes (p <0.009 and p <0.026).Conclusion. Surgical correction of the upper third of the ureter by a tubularized pelvis flap is a highly effective and safe method of reconstruction of the upper urinary tract. The main negative factors in the prognosis of this operation results are the secondary nature of the operation, the performance of the dismembered tubularized flap pyeloplasty because of the extended strictures of the upper third of the ureter, and the duration of the operation more than 120 minute

    Expression of Interest for a Phase-II LHCb Upgrade: Opportunities in flavour physics, and beyond, in the HL-LHC era

    No full text
    https://cds.cern.ch/record/224431

    Expression of Interest for a Phase-II LHCb Upgrade: Opportunities in flavour physics, and beyond, in the HL-LHC era

    No full text
    A Phase-II Upgrade is proposed for the LHCb experiment in order to take full advantage of the flavour-physics opportunities at the HL-LHC, and other topics that can be studied with a forward spectrometer. This Upgrade, which will be installed in Long Shutdown 4 of the LHC (2030), will build on the strengths of the current experiment and the Phase-I Upgrade, but will consist of re-designed sub-systems that can operate at a luminosity of 2×1034cm−2s−1, ten times that of the Phase-I Upgrade detector. New and improved detector components will increase the intrinsic performance of the experiment in certain key areas. In particular the installation of a tungsten sampling electromagnetic calorimeter will widen LHCb's capabilities for decays involving π0 and η mesons, electrons, and photons from loop-level penguin processes. The physics motivation is presented, and the prospects for operating the LHCb Interaction Point at high luminosity are assessed. The challenges for the detector are described and possible solutions are discussed. Finally, the key R\&D areas are summarised, together with a set of initial modifications suitable for implementation during Long Shutdown 3 (2024--2026)

    Search for the rare hadronic decay Bs0ppˉB_s^0\to p \bar{p}

    No full text
    A search for the rare hadronic decay Bs0→pp¯ is performed using proton-proton collision data recorded by the LHCb experiment at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 6  fb-1. No evidence of the decay is found and an upper limit on its branching fraction is set at B(Bs0→pp¯)&lt;4.4(5.1)×10-9 at 90% (95%) confidence level; this is currently the world’s best upper limit. The decay mode B0→pp¯ is measured with very large significance, confirming the first observation by the LHCb experiment in 2017. The branching fraction is determined to be B(B0→pp¯)=(1.27±0.15±0.05±0.04)×10-8, where the first uncertainty is statistical, the second is systematic and the third is due to the external branching fraction of the normalization channel B0→K+π-. The combination of the two LHCb measurements of the B0→pp¯ branching fraction yields B(B0→pp¯)=(1.27±0.13±0.05±0.03)×10-8.A search for the rare hadronic decay Bs0ppˉB_s^0\to p \bar{p} is performed using proton-proton collision data recorded by the LHCb experiment at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 6 fb1^{-1}. No evidence of the decay is found and an upper limit on its branching fraction is set at B(Bs0ppˉ)<4.4 (5.1)×109{\cal B}(B_s^0\to p \bar{p}) < 4.4~(5.1) \times 10^{-9} at 90% (95%) confidence level; this is currently the world's best upper limit. The decay mode B0ppˉB^0\to p \bar{p} is measured with very large significance, confirming the first observation by the LHCb experiment in 2017. The branching fraction is determined to be B(B0ppˉ)=(1.27±0.15±0.05±0.04)×108{\cal B}(B^0\to p \bar{p}) = \rm (1.27 \pm 0.15 \pm 0.05 \pm 0.04) \times 10^{-8}, where the first uncertainty is statistical, the second is systematic and the third is due to the external branching fraction of the normalization channel B0K+πB^0\to K^+\pi^-. The combination of the two LHCb measurements of the B0ppˉB^0\to p \bar{p} branching fraction yields B(B0ppˉ)=(1.27±0.13±0.05±0.03)×108{\cal B}(B^0\to p \bar{p}) = \rm (1.27 \pm 0.13 \pm 0.05 \pm 0.03) \times 10^{-8}

    Observation of sizeable ω\omega contribution to χc1(3872)π+πJ/ψ\chi_{c1}(3872) \to \pi^+\pi^- J/\psi decays

    No full text
    Resonant structures in the dipion mass spectrum from χc1(3872)π+πJ/ψ\chi_{c1}(3872)\to\pi^+\pi^- J/\psi decays, produced via B+K+χc1(3872)B^+\to K^+\chi_{c1}(3872) decays, are analyzed using proton-proton collision data collected by the LHCb experiment, corresponding to an integrated luminosity of 9 fb1^{-1}. A sizeable contribution from the isospin conserving χc1(3872)ωJ/ψ\chi_{c1}(3872)\to\omega J/\psi decay is established for the first time, (21.4±2.3±2.0)%(21.4\pm2.3\pm2.0)\%, with a significance of more than 7.1σ7.1\sigma. The amplitude of isospin violating decay, χc1(3872)ρ0J/ψ\chi_{c1}(3872)\to\rho^0 J/\psi, relative to isospin conserving decay, χc1(3872)ωJ/ψ\chi_{c1}(3872)\to\omega J/\psi, is properly determined, and it is a factor of six larger than expected for a pure charmonium state.Resonant structures in the dipion mass spectrum from χc1(3872)→π+π-J/ψ decays, produced via B+→K+χc1(3872) decays, are analyzed using proton-proton collision data collected by the LHCb experiment, corresponding to an integrated luminosity of 9  fb-1. A sizeable contribution from the isospin conserving χc1(3872)→ωJ/ψ decay is established for the first time, (21.4±2.3±2.0)%, with a significance of more than 7.1σ. The amplitude of isospin violating decay, χc1(3872)→ρ0J/ψ, relative to isospin conserving decay, χc1(3872)→ωJ/ψ, is properly determined, and it is a factor of 6 larger than expected for a pure charmonium state.Resonant structures in the dipion mass spectrum from χc1(3872)π+πJ/ψ\chi_{c1}(3872)\to\pi^+\pi^- J/\psi decays, produced via B+K+χc1(3872)B^+\to K^+\chi_{c1}(3872) decays, are analyzed using proton-proton collision data collected by the LHCb experiment, corresponding to an integrated luminosity of 9 fb1fb^{-1}. A sizeable contribution from the isospin conserving χc1(3872)ωJ/ψ\chi_{c1}(3872)\to\omega J/\psi decay is established for the first time, (21.4±2.3±2.0)%(21.4\pm2.3\pm2.0)\%, with a significance of more than 7.1σ7.1\sigma. The amplitude of isospin violating decay, χc1(3872)ρ0J/ψ\chi_{c1}(3872)\to\rho^0 J/\psi, relative to isospin conserving decay, χc1(3872)ωJ/ψ\chi_{c1}(3872)\to\omega J/\psi, is properly determined, and it is a factor of six larger than expected for a pure charmonium state

    Measurement of CP asymmetries in D(s)+ηπ+ {D}_{(s)}^{+}\to \eta {\pi}^{+} and D(s)+ηπ+ {D}_{(s)}^{+}\to {\eta}^{\prime }{\pi}^{+} decays

    No full text
    Searches for CP violation in the decays D(s)+ηπ+ {D}_{(s)}^{+}\to \eta {\pi}^{+} and D(s)+ηπ+ {D}_{(s)}^{+}\to {\eta}^{\prime }{\pi}^{+} are performed using pp collision data corresponding to 6 fb1^{−1} of integrated luminosity collected by the LHCb experiment. The calibration channels D(s)+ϕπ+ {D}_{(s)}^{+}\to \phi {\pi}^{+} are used to remove production and detection asymmetries. The resulting CP-violating asymmetries areACP=(D+ηπ+)=(0.34±0.66±0.16±0.05)%,ACP=(Ds+ηπ+)=(0.32±0.51±0.12)%,ACP=(D+ηπ+)=(0.49±0.18±0.06±0.05)%,ACP=(Ds+ηπ+)=(0.01±0.12±0.08)%, {\displaystyle \begin{array}{l}{\mathcal{A}}^{CP}=\left({D}^{+}\to \eta {\pi}^{+}\right)=\left(0.34\pm 0.66\pm 0.16\pm 0.05\right)\%,\\ {}{\mathcal{A}}^{CP}=\left({D}_s^{+}\to \eta {\pi}^{+}\right)=\left(0.32\pm 0.51\pm 0.12\right)\%,\\ {}\begin{array}{l}{\mathcal{A}}^{CP}=\left({D}^{+}\to {\eta}^{\prime }{\pi}^{+}\right)=\left(0.49\pm 0.18\pm 0.06\pm 0.05\right)\%,\\ {}{\mathcal{A}}^{CP}=\left({D}_s^{+}\to {\eta}^{\prime }{\pi}^{+}\right)=\left(0.01\pm 0.12\pm 0.08\right)\%,\end{array}\end{array}} where the first uncertainty is statistical, the second is systematic and the third, relevant for the D+^{+} channels, is due to the uncertainty on ACP=(D+ϕπ+) {\mathcal{A}}^{CP}=\left({D}^{+}\to \phi {\pi}^{+}\right) . These measurements, currently the most precise for three of the four channels considered, are consistent with the absence of CP violation. A combination of these results with previous LHCb measurements is presented.[graphic not available: see fulltext]Searches for CPCP violation in the decays D(s)+ηπ+D^+_{(s)}\rightarrow \eta \pi^+ and D(s)+ηπ+D^+_{(s)}\rightarrow \eta^{\prime} \pi^+ are performed using pppp collision data corresponding to 6 fb1^{-1} of integrated luminosity collected by the LHCb experiment. The calibration channels D(s)+ϕπ+D^+_{(s)}\rightarrow \phi \pi^+ are used to remove production and detection asymmetries. The resulting CPCP-violating asymmetries are ACP(D+ηπ+)=(0.34±0.66±0.16±0.05)%A^{CP}(D^+ \rightarrow \eta \pi^+) = (0.34 \pm 0.66 \pm 0.16 \pm 0.05)\%, ACP(Ds+ηπ+)=(0.32±0.51±0.12)%A^{CP}(D^+_s \rightarrow \eta \pi^+) = (0.32 \pm 0.51 \pm 0.12)\%, ACP(D+ηπ+)=(0.49±0.18±0.06±0.05)%A^{CP}(D^+ \rightarrow \eta^{\prime} \pi^+) = (0.49 \pm 0.18 \pm 0.06 \pm 0.05)\%, ACP(Ds+ηπ+)=(0.01±0.12±0.08)%A^{CP}(D^+_s \rightarrow \eta^{\prime} \pi^+) = (0.01 \pm 0.12 \pm 0.08)\%, where the first uncertainty is statistical, the second is systematic and the third, relevant for the D+D^+ channels, is due to the uncertainty on ACP(D+ϕπ+)A^{CP}(D^+ \to \phi \pi^+). These measurements, currently the most precise for three of the four channels considered, are consistent with the absence of CPCP violation. A combination of these results with previous LHCb measurements is presented

    Nuclear modification factor of neutral pions in the forward and backward regions in ppPb collisions

    No full text
    The nuclear modification factor of neutral pions is measured in proton-lead collisions collected at a center-of-mass energy per nucleon of 8.168.16 TeV with the LHCb detector. The π0\pi^0 production cross section is measured differentially in transverse momentum (pTp_{T}) for 1.5π0 production cross section is measured differentially in transverse momentum (pT) for 1.5<pT<10.0  GeV and in center-of-mass pseudorapidity (ηc.m.) regions 2.5<ηc.m.<3.5 (forward) and -4.0<ηc.m.<-3.0 (backward) defined relative to the proton beam direction. The forward measurement shows a sizable suppression of π0 production, while the backward measurement shows the first evidence of π0 enhancement in proton-lead collisions at the LHC. Together, these measurements provide precise constraints on models of nuclear structure and particle production in high-energy nuclear collisions.The nuclear modification factor of neutral pions is measured in proton-lead collisions collected at a center-of-mass energy per nucleon of 8.16~{\rm TeV}withtheLHCbdetector.The with the LHCb detector. The \pi^0productioncrosssectionismeasureddifferentiallyintransversemomentum( production cross section is measured differentially in transverse momentum (p_{\rm T})for) for 1.5<p_{\rm T}<10.0~{\rm GeV}andincenterofmasspseudorapidity( and in center-of-mass pseudorapidity (\eta_{\rm c.m.})regions) regions 2.5<\eta_{\rm c.m.}<3.5(forward)and (forward) and -4.0<\eta_{\rm c.m.}<-3.0(backward)definedrelativetotheprotonbeamdirection.Theforwardmeasurementshowsasizablesuppressionof (backward) defined relative to the proton beam direction. The forward measurement shows a sizable suppression of \pi^0production,whilethebackwardmeasurementshowsthefirstevidenceof production, while the backward measurement shows the first evidence of \pi^0$ enhancement in proton-lead collisions at the LHC. Together, these measurements provide precise constraints on models of nuclear structure and particle production in high-energy nuclear collisions

    Amplitude analysis of the Λc+pKπ+\Lambda^+_c\to pK^-\pi^+ decay and Λc+\Lambda^+_c baryon polarization measurement in semileptonic beauty hadron decays

    No full text
    An amplitude analysis of Λc+pKπ+\Lambda^+_c \to pK^-\pi^+ decays together with a measurement of the Λc+\Lambda^+_c polarization vector in semileptonic beauty hadron decays is presented. A sample of 400000400\,000 candidates is selected from proton-proton collisions recorded by the LHCb detector at a center-of-mass energy of 13 TeV. An amplitude model is developed and the resonance fractions as well as two- and three-body decay parameters are reported. The mass and width of the Λ(2000)\Lambda(2000) state are also determined. A significant Λc+\Lambda^+_c polarization is found. A large sensitivity of the Λc+pKπ+\Lambda^+_c \to pK^-\pi^+ decay to the polarization is seen, making the amplitude model suitable for Λc+\Lambda^+_c polarization measurements in other systems.An amplitude analysis of Λc+→pK-π+ decays together with a measurement of the Λc+ polarization vector in semiōleptonic beauty hadron decays is presented. A sample of 400 000 candidates is selected from proton-proton collisions recorded by the LHCb detector at a center-of-mass energy of 13 TeV. An amplitude model is developed and the resonance fractions as well as two- and three-body decay parameters are reported. The mass and width of the Λ(2000) state are also determined. A significant Λc+ polarization is found. A large sensitivity of the Λc+→pK-π+ decay to the polarization is seen, making the amplitude model suitable for Λc+ polarization measurements in other systems.An amplitude analysis of Λc+pKπ+\Lambda^+_c \to pK^-\pi^+ decays together with a measurement of the Λc+\Lambda^+_c polarization vector in semileptonic beauty hadron decays is presented. A sample of 400000400\,000 candidates is selected from proton-proton collisions recorded by the LHCb detector at a center-of-mass energy of 13 TeV. An amplitude model is developed and the resonance fractions as well as two- and three-body decay parameters are reported. The mass and width of the Λ(2000)\Lambda(2000) state are also determined. A significant Λc+\Lambda^+_c polarization is found. A large sensitivity of the Λc+pKπ+\Lambda^+_c \to pK^-\pi^+ decay to the polarization is seen, making the amplitude model suitable for Λc+\Lambda^+_c polarization measurements in other systems

    Measurement of the W boson mass

    No full text
    International audienceThe W boson mass is measured using proton-proton collision data at s \sqrt{s} = 13 TeV corresponding to an integrated luminosity of 1.7 fb1^{−1} recorded during 2016 by the LHCb experiment. With a simultaneous fit of the muon q/pT_{T} distribution of a sample of W → μν decays and the ϕ^{*} distribution of a sample of Z → μμ decays the W boson mass is determined to bemw=80354±23stat±10exp±17theory±9PDFMeV, {m}_w=80354\pm {23}_{\mathrm{stat}}\pm {10}_{\mathrm{exp}}\pm {17}_{\mathrm{theory}}\pm {9}_{\mathrm{PDF}}\mathrm{MeV}, where uncertainties correspond to contributions from statistical, experimental systematic, theoretical and parton distribution function sources. This is an average of results based on three recent global parton distribution function sets. The measurement agrees well with the prediction of the global electroweak fit and with previous measurements.[graphic not available: see fulltext

    Evidence of a J/ψΛJ/\psi\Lambda structure and observation of excited Ξ\Xi^- states in the ΞbJ/ψΛK\Xi^-_b \to J/\psi\Lambda K^- decay

    No full text
    First evidence of a structure in the J/ψΛJ/\psi{\Lambda} invariant mass distribution is obtained from an amplitude analysis of ΞbJ/ψΛK\Xi_b^-{\rightarrow}J/\psi{\Lambda}K^- decays. The observed structure is consistent with being due to a charmonium pentaquark with strangeness with a significance of 3.1σ3.1\sigma including systematic uncertainties and look-elsewhere effect. Its mass and width are determined to be 4458.8±2.91.1+4.74458.8\pm2.9^{+4.7}_{-1.1} MeV and 17.3±6.55.7+8.017.3\pm6.5^{+8.0}_{-5.7} MeV, respectively, where the quoted uncertainties are statistical and systematic. The structure is also consistent with being due to two resonances. In addition, the narrow excited Ξ\Xi^- states, Ξ(1690)\Xi(1690)^- and Ξ(1820)\Xi(1820)^-, are seen for the first time in a Ξb\Xi^-_b decay, and their masses and widths are measured with improved precision. The analysis is performed using pppp collision data corresponding to a total integrated luminosity of 9 fb1^{-1}, collected with the LHCb experiment at centre-of-mass energies of 7, 8 and 13 TeV
    corecore