67 research outputs found

    A study of CP violation in B-+/- -> DK +/- and B-+/- -> D pi(+/-) decays with D -> (KSK +/-)-K-0 pi(-/+) final states

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    A first study of CP violation in the decay modes B±→[KS0K±π∓]Dh±B^\pm\to [K^0_{\rm S} K^\pm \pi^\mp]_D h^\pm and B±→[KS0K∓π±]Dh±B^\pm\to [K^0_{\rm S} K^\mp \pi^\pm]_D h^\pm, where hh labels a KK or π\pi meson and DD labels a D0D^0 or D‟0\overline{D}^0 meson, is performed. The analysis uses the LHCb data set collected in pppp collisions, corresponding to an integrated luminosity of 3 fb−1^{-1}. The analysis is sensitive to the CP-violating CKM phase Îł\gamma 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 Îł\gamma using other decay modes

    Studies of beauty baryon decays to D0ph− and Λ+ch− final states

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    Measurement of Upsilon production in collisions at root s=2.76 TeV

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    The production of ΄(1S)\Upsilon(1S), ΄(2S)\Upsilon(2S) and ΄(3S)\Upsilon(3S) mesons decaying into the dimuon final state is studied with the LHCb detector using a data sample corresponding to an integrated luminosity of 3.3 pb−1pb^{-1} collected in proton-proton collisions at a centre-of-mass energy of s=2.76\sqrt{s}=2.76 TeV. The differential production cross-sections times dimuon branching fractions are measured as functions of the ΄\Upsilon transverse momentum and rapidity, over the ranges $p_{\rm T} Upsilon(1S) X) x B(Upsilon(1S) -> mu+mu-) = 1.111 +/- 0.043 +/- 0.044 nb, sigma(pp -> Upsilon(2S) X) x B(Upsilon(2S) -> mu+mu-) = 0.264 +/- 0.023 +/- 0.011 nb, sigma(pp -> Upsilon(3S) X) x B(Upsilon(3S) -> mu+mu-) = 0.159 +/- 0.020 +/- 0.007 nb, where the first uncertainty is statistical and the second systematic

    Study of forward Z + jet production in pp collisions at √s=7 TeV

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    A measurement of the Z(→Ό+Ό−)Z(\rightarrow\mu^+\mu^-)+jet production cross-section in pppp collisions at a centre-of-mass energy s=7\sqrt{s} = 7 TeV is presented. The analysis is based on an integrated luminosity of 1.0 fb−11.0\,\text{fb}^{-1} recorded by the LHCb experiment. Results are shown with two jet transverse momentum thresholds, 10 and 20 GeV, for both the overall cross-section within the fiducial volume, and for six differential cross-section measurements. The fiducial volume requires that both the jet and the muons from the Z boson decay are produced in the forward direction (2.0<η<4.52.0<\eta<4.5). The results show good agreement with theoretical predictions at the second-order expansion in the coupling of the strong interaction.A measurement of the Z(→Ό+Ό−)Z(\rightarrow\mu^+\mu^-)+jet production cross-section in pppp collisions at a centre-of-mass energy s=7\sqrt{s} = 7 TeV is presented. The analysis is based on an integrated luminosity of 1.0 fb−11.0\,\text{fb}^{-1} recorded by the LHCb experiment. Results are shown with two jet transverse momentum thresholds, 10 and 20 GeV, for both the overall cross-section within the fiducial volume, and for six differential cross-section measurements. The fiducial volume requires that both the jet and the muons from the Z boson decay are produced in the forward direction (2.0<η<4.52.0<\eta<4.5). The results show good agreement with theoretical predictions at the second-order expansion in the coupling of the strong interaction

    Etude des sections efficaces et des asymétries di-leptoniques à LEP2. Contraintes sur la physique au-delà du ModÚle Standard.

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    I describe in this HDR the scientific works that I have done since my PhD, defended in 1994. The first part of these works was devoted to the development of detectors within the BaBar experiment. The second part, more extensively described here, was the study of the di-leptonic events produced in the ALEPH experiment at LEP2. In the BaBar experiment, I initially contributed to the feasibility study of a Cerenkov counter dedicated to the identification of charged particles. I had then the responsibility of the construction of a wire chamber for the monitoring of the gain, installed in the gas distribution system of the BaBar drift chamber. These activities included design and simulation of instruments as well as analysis of tests data. Then, I participated to the LEP2 data analysis by measuring cross-sections and forward-backward asymmetries of the di-leptonic processes. I made the interpretation of these measurements under various scenarios of new physics beyond the Standard Model, such as four fermions contact interactions, extra-dimensions and production of sneutrinos with R-parity violation. Moreover, I participated to the combination of the di-leptonic results from the four LEP experiments. Those years between construction of detectors and data analysis in the field of electroweak physics make me join today the thematic of neutrinos. The research plan that I present here focuses on this thematic, especially on my future involvement in the Laguna-LBNO project. Finally, I describe also here my various scientific outreach activities, especially toward the scholars, because, in addition to my research and teaching, this is a non-negligible part of my activity in the past decade.Sont décrits dans cette HDR, les travaux scientifiques que j'ai réalisés depuis ma thÚse, soutenue en 1994. La premiÚre partie de ces travaux fut consacrée à la construction et au développement de détecteurs au sein de l'expérience BaBar. La seconde partie, plus longuement développée ici, fut l'étude des processus di-leptoniques e+e- ->l+l- au sein de l'expérience ALEPH à LEP2. Dans l'expérience BaBar, j'ai tout d'abord contribué à l'étude de faisabilité d'un compteur Cerenkov à seuil dédié à l'identification des particules chargées. J'ai ensuite eu la responsabilité de la construction d'une chambre à fils de contrÎle du gain installée dans le systÚme de gaz de la chambre à dérive de BaBar. Ces activités incluaient un travail de conception et de simulation de détecteurs ainsi qu'un travail d'analyse de données de tests. J'ai ensuite participé à l'analyse des données de LEP2 par la mesure des sections efficaces et des asymétries avant-arriÚre des processus di-leptoniques. J'ai effectué l'interprétation de ces mesures dans le cadre de différents scénarios de nouvelle physique au-delà du ModÚle Standard, tels que les interactions de contact à quatre fermions, les dimensions supplémentaires ou la production de sneutrinos avec violation de R-parité. J'ai de plus participé à la combinaison des résultats di-leptoniques des quatre expériences LEP. Ces années passées entre construction de détecteurs et analyse de données dans le domaine de la physique électrofaible m'incitent à rejoindre aujourd'hui la thématique des neutrinos. Le projet de recherche que je présente est centré sur cette thématique, notamment sur mon implication future dans le projet Laguna-LBNO. Enfin, je décris aussi dans ce mémoire mes différentes activités de diffusion scientifique, notamment auprÚs du public scolaire, car, en plus de mon travail de recherche et d'enseignement, c'est un aspect important de mon activité de ces dix derniÚres années

    El siglo de Oro en escena

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    Del teatro de SĂĄnchez de Badajoz (siglo xvi) al de Bances Candamo (finales del xvii), de las mĂșltiples riquezas de la comedia lopesca a las excelencias del teatro calderoniano, de la prosa cervantina a la de un Mateo AlemĂĄn, del Pinciano al maestro Correas, y «trecientas cosas mĂĄs»: los artĂ­culos reunidos en este libro componen un extenso panorama de los mĂĄs recientes resultados de la investigaciĂłn internacional sobre toda la literatura española del Siglo de Oro, ofrecidos al profesor Marc Vitse por sus mĂĄs destacados discĂ­pulos, amigos y admiradores.À Marc,Odett

    Oral anticoagulant safety in family practice: prognostic accuracy of Bleeding Risk Scores (from the CACAO study)

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    International audienceAbstract Background To assess bleeding risk of patients treated by oral anticoagulants, several scores have been constructed to assist physicians in the evaluation of the benefit risk. Most of these scores lack a strong enough level of evidence for use in family practice. Objective To assess the predictive prognostic accuracy of 13 scores designed to assess the risk of major or clinically relevant non-major (CRNM) bleeding events in a French ambulatory cohort receiving Vitamin-K antagonists (VKA) or direct oral anticoagulants (DOACs) in a family practice setting. Methods CACAO (Comparison of Accidents and their Circumstances with Oral Anticoagulants) was a multicentre prospective cohort of ambulatory patients prescribed oral anticoagulants. We selected patients from the cohort who had received an oral anticoagulant because of non-valvular atrial fibrillation (NVAF) and/or venous thromboembolism (VTE) to be followed during one year by their GP. The following scores were calculated: mOBRI, Shireman, Kuijer, HEMORR2HAGES, ATRIA, HAS-BLED, RIETE, VTE-BLEED, ACCP score, Rutherford, ABH-Score, GARFIEL-AF, and Outcomes Registry for Better InformedTreatment of Atrial Fibrillation (ORBIT). Prognostic accuracy was assessed by using receiver operating characteristic curves and c-statistics. Results During 1 year, 3,082 patients were followed. All of the scores demonstrated only poor to moderate ability to predict major bleeding or CRNM in NVAF patients on DOACs (c-statistic: 0.41–0.66 and 0.45–0.58), respectively. The results were only slightly better for patients prescribed VKA (0.47–0.66 and 0.5–0.55, respectively) in this indication. The results were also unsatisfactory in patients treated for VTE. Conclusion None of the scores demonstrated satisfactory discriminatory ability when used in family practice. Clinical Trial Registration ClinicalTrials.gov NCT0237677

    Patients treated with vitamin K oral anticoagulants in family practice: a new approach to bleeding risk assessment. An ancillary study by the CACAO prospective general practice cohort

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    International audienceAbstract Background The ability of bleeding risk scores to predict major bleeding (MB) or clinically relevant nonmajor bleeding (CRNMB) remains a topic of contention, particularly in nonselected patients in family practice. In addition, the capacity to predict bleeding risk using simple variables has yet to be established. Objectives The main objective was to confirm that severe anemia was the most predictive factor for the estimation of bleeding risk in patients treated with vitamin K antagonists (VKAs). Secondary objectives were to test the capacity of different bleeding scores to detect high-risk patients. Subsequently, the impact of functional decline on bleeding incidence was explored. Methods The CACAO study was a multicenter prospective cohort study of patients who, due to nonvalvular atrial fibrillation (NVAF) and/or venous thromboembolism (VTE), had been prescribed an oral anticoagulant by their general practitioner (GP) as a prophylactic measure. Patient characteristics were collected at the time of inclusion by GPs, who then monitored them in accordance with standard practice for one year. MB and CRNMB were the main outcomes for one year. By applying this approach, a total of 13 scores were analyzed. Results Aaemia was found to be strongly associated with MB (HR: 2.77, 95% CI: 1.2–6.36), with a particularly pronounced association observed in cases of severe anemia (HR: 12.9, 95% CI: 2.76–60.35). Twelve out of 27 MB cases were not identified by at least half of the scores. By contrast, functional decline was identified as a novel factor associated with MB (HR: 2.45, 95% CI: 1.13–5.31). Conclusions Preexisting anemia is a major prognostic factor associated with the occurrence of bleeding. It seems relevant to suggest that functional decline should be considered by GPs when assessing bleeding risk

    Measurement of the Bc+B_c^+ meson lifetime using Bc+→J/ψΌ+ΜΌXB_c^+ \to J/\psi\mu^+ \nu_{\mu} X decays

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    The lifetime of the Bc+B_c^+ meson is measured using semileptonic decays having a J/ψJ/\psi meson and a muon in the final state. The data, corresponding to an integrated luminosity of 2 fb−12\mathrm{~fb^{-1}}, are collected by the LHCb detector in pppp collisions at a centre-of-mass energy of 8 TeV8\,\mathrm{TeV}. The measured lifetime is τ=509±8±12 fs,\tau = 509 \pm 8 \pm 12 \mathrm{~fs}, where the first uncertainty is statistical and the second is systematic.The lifetime of the Bc+B_c^+ meson is measured using semileptonic decays having a J ⁣/â€‰âŁÏˆJ\!/\!\psi meson and a muon in the final state. The data, corresponding to an integrated luminosity of 2 fb−12\mathrm{~fb^{-1}}, are collected by the LHCb detector in pppp collisions at a centre-of-mass energy of 8 TeV8\,\mathrm{TeV}. The measured lifetime is τ=509±8±12 fs,\tau = 509 \pm 8 \pm 12 \mathrm{~fs}, where the first uncertainty is statistical and the second is systematic.The lifetime of the B c + meson is measured using semileptonic decays having a J / ψ meson and a muon in the final state. The data, corresponding to an integrated luminosity of 2 fb - 1 , are collected by the LHCb detector in p p collisions at a centre-of-mass energy of 8 TeV. The measured lifetime is τ = 509 ± 8 ± 12 fs , where the first uncertainty is statistical and the second is systematic

    Deep Underground Neutrino Experiment (DUNE), Far Detector Technical Design Report, Volume I Introduction to DUNE

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    International audienceThe preponderance of matter over antimatter in the early universe, the dynamics of the supernovae that produced the heavy elements necessary for life, and whether protons eventually decay—these mysteries at the forefront of particle physics and astrophysics are key to understanding the early evolution of our universe, its current state, and its eventual fate. The Deep Underground Neutrino Experiment (DUNE) is an international world-class experiment dedicated to addressing these questions as it searches for leptonic charge-parity symmetry violation, stands ready to capture supernova neutrino bursts, and seeks to observe nucleon decay as a signature of a grand unified theory underlying the standard model. The DUNE far detector technical design report (TDR) describes the DUNE physics program and the technical designs of the single- and dual-phase DUNE liquid argon TPC far detector modules. This TDR is intended to justify the technical choices for the far detector that flow down from the high-level physics goals through requirements at all levels of the Project. Volume I contains an executive summary that introduces the DUNE science program, the far detector and the strategy for its modular designs, and the organization and management of the Project. The remainder of Volume I provides more detail on the science program that drives the choice of detector technologies and on the technologies themselves. It also introduces the designs for the DUNE near detector and the DUNE computing model, for which DUNE is planning design reports. Volume II of this TDR describes DUNE's physics program in detail. Volume III describes the technical coordination required for the far detector design, construction, installation, and integration, and its organizational structure. Volume IV describes the single-phase far detector technology. A planned Volume V will describe the dual-phase technology
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