50 research outputs found

    Measurement of CP observables in B± → D(⁎)K± and B± → D(⁎)π± decays

    Get PDF
    Measurements of CP observables in B ± →D (⁎) K ± and B ± →D (⁎) π ± decays are presented, where D (⁎) indicates a neutral D or D ⁎ meson that is an admixture of D (⁎)0 and DÂŻ (⁎)0 states. Decays of the D ⁎ meson to the Dπ 0 and DÎł final states are partially reconstructed without inclusion of the neutral pion or photon, resulting in distinctive shapes in the B candidate invariant mass distribution. Decays of the D meson are fully reconstructed in the K ± π ∓ , K + K − and π + π − final states. The analysis uses a sample of charged B mesons produced in pp collisions collected by the LHCb experiment, corresponding to an integrated luminosity of 2.0, 1.0 and 2.0 fb −1 taken at centre-of-mass energies of s=7, 8 and 13 TeV, respectively. The study of B ± →D ⁎ K ± and B ± →D ⁎ π ± decays using a partial reconstruction method is the first of its kind, while the measurement of B ± →DK ± and B ± →Dπ ± decays is an update of previous LHCb measurements. The B ± →DK ± results are the most precise to date

    First observation of forward Z→bbˉZ \rightarrow b \bar{b} production in pppp collisions at s=8\sqrt{s}=8 TeV

    Get PDF
    The decay Z→bb¯ is reconstructed in pp collision data, corresponding to 2 fb −1 of integrated luminosity, collected by the LHCb experiment at a centre-of-mass energy of s=8 TeV. The product of the Z production cross-section and the Z→bb¯ branching fraction is measured for candidates in the fiducial region defined by two particle-level b -quark jets with pseudorapidities in the range 2.220 GeV and dijet invariant mass in the range 4520GeVanddijetinvariantmassintherange GeV and dijet invariant mass in the range 45 < m_{jj} < 165GeV.Fromasignalyieldof GeV. From a signal yield of 5462 \pm 763 Z \rightarrow b \bar{b}events,wheretheuncertaintyisstatistical,aproductioncross−sectiontimesbranchingfractionof events, where the uncertainty is statistical, a production cross-section times branching fraction of 332 \pm 46 \pm 59pbisobtained,wherethefirstuncertaintyisstatisticalandthesecondsystematic.Themeasuredsignificanceofthesignalyieldis6.0standarddeviations.Thismeasurementrepresentsthefirstobservationofthe pb is obtained, where the first uncertainty is statistical and the second systematic. The measured significance of the signal yield is 6.0 standard deviations. This measurement represents the first observation of the Z \rightarrow b \bar{b}productionintheforwardregionof production in the forward region of pp$ collisions

    Pigmented villonodular synovitis of the hip. A case report and review of the literature

    No full text
    A 73-year-old patient, whose hip was completely destroyed by pigmented villonodular synovitis, was successfully treated by a total prosthetic replacement of this articulation. The etiopathogenesis of the illness is uncertain. Its' localization in the hip is, fortunately, a rare occurrence. It can be responsible for frequently extensive articular destruction which is even more dramatic when it affects young patients, whose average age is 35. Only early diagnosis permits conservative surgical treatment: total synovectomy associated with curettage of the foyers of osteolysis and their filling with bone grafts. If the destructive lesions are too extensive, an arthrodesis or replacement arthroplasty are proposed. © 1991 Acta Medica Belgica.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

    The LHCb Online system in 2020: trigger-free read-out with (almost exclusively) off-the-shelf hardware

    No full text
    International audienceThe LHCb experiment at CERN has decided to optimise its physics reach by removing the first level hardware trigger for 2020 and beyond. In addition to requiring fully redesigned front-end electronics this design creates interesting challenges for the data-acquisition and the rest of the online computing system. Such a system can only be realized within realistic cost using as much off-the-shelf hardware as possible. Relevant technologies evolve very quickly and thus the system design is architecture-centred and tries to avoid to depend too much on specific technologies. In this paper we describe the design, the motivations for various choices and the current favoured options for the implementation, and the status of the R&D. We will cover the back-end readout, which contains the only custom-made component, the event-building, the event-filter infrastructure, and storage
    corecore