16 research outputs found

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

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    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

    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

    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

    Modern Methods of Diagnostics and Treatment of Neurodegenerative Diseases and Depression

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    This paper discusses the promising areas of research into machine learning applications for the prevention and correction of neurodegenerative and depressive disorders. These two groups of disorders are among the leading causes of decline in the quality of life in the world when estimated using disability-adjusted years. Despite decades of research, the development of new approaches for the assessment (especially pre-clinical) and correction of neurodegenerative diseases and depressive disorders remains among the priority areas of research in neurophysiology, psychology, genetics, and interdisciplinary medicine. Contemporary machine learning technologies and medical data infrastructure create new research opportunities. However, reaching a consensus on the application of new machine learning methods and their integration with the existing standards of care and assessment is still a challenge to overcome before the innovations could be widely introduced to clinics. The research on the development of clinical predictions and classification algorithms contributes towards creating a unified approach to the use of growing clinical data. This unified approach should integrate the requirements of medical professionals, researchers, and governmental regulators. In the current paper, the current state of research into neurodegenerative and depressive disorders is presented

    Modern Methods of Diagnostics and Treatment of Neurodegenerative Diseases and Depression

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    This paper discusses the promising areas of research into machine learning applications for the prevention and correction of neurodegenerative and depressive disorders. These two groups of disorders are among the leading causes of decline in the quality of life in the world when estimated using disability-adjusted years. Despite decades of research, the development of new approaches for the assessment (especially pre-clinical) and correction of neurodegenerative diseases and depressive disorders remains among the priority areas of research in neurophysiology, psychology, genetics, and interdisciplinary medicine. Contemporary machine learning technologies and medical data infrastructure create new research opportunities. However, reaching a consensus on the application of new machine learning methods and their integration with the existing standards of care and assessment is still a challenge to overcome before the innovations could be widely introduced to clinics. The research on the development of clinical predictions and classification algorithms contributes towards creating a unified approach to the use of growing clinical data. This unified approach should integrate the requirements of medical professionals, researchers, and governmental regulators. In the current paper, the current state of research into neurodegenerative and depressive disorders is presented

    Studies of beauty baryon decays to D0ph−D^0 ph^- and Λc+h−\Lambda_c^+ h^- final states

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    Decays of beauty baryons to the D0ph−D^0 p h^- and Λc+h−\Lambda_c^+ h^- final states (where hh indicates a pion or a kaon) are studied using a data sample of pppp collisions, corresponding to an integrated luminosity of 1.0 fb−1^{-1}, collected by the LHCb detector. The Cabibbo-suppressed decays Λb0→D0pK−\Lambda_b^0\to D^0 p K^- and Λb0→Λc+K−\Lambda_b^0\to \Lambda_c^+ K^- are observed and their branching fractions are measured with respect to the decays Λb0→D0pπ−\Lambda_b^0\to D^0 p \pi^- and Λb0→Λc+π−\Lambda_b^0\to \Lambda_c^+ \pi^-. In addition, the first observation is reported of the decay of the neutral beauty-strange baryon Ξb0\Xi_b^0 to the D0pK−D^0 p K^- final state, and a measurement of the Ξb0\Xi_b^0 mass is performed. Evidence of the Ξb0→Λc+K−\Xi_b^0\to \Lambda_c^+ K^- decay is also reported.Decays of beauty baryons to the D0ph− and Λc+h− final states (where h indicates a pion or a kaon) are studied using a data sample of pp collisions, corresponding to an integrated luminosity of 1.0  fb−1, collected by the LHCb detector. The Cabibbo-suppressed decays Λb0→D0pK− and Λb0→Λc+K− are observed, and their branching fractions are measured with respect to the decays Λb0→D0pπ− and Λb0→Λc+π−. In addition, the first observation is reported of the decay of the neutral beauty-strange baryon Ξb0 to the D0pK− final state, and a measurement of the Ξb0 mass is performed. Evidence of the Ξb0→Λc+K− decay is also reported.Decays of beauty baryons to the D0ph−D^0 p h^- and Λc+h−\Lambda_c^+ h^- final states (where hh indicates a pion or a kaon) are studied using a data sample of pppp collisions, corresponding to an integrated luminosity of 1.0 fb−1^{-1}, collected by the LHCb detector. The Cabibbo-suppressed decays Λb0→D0pK−\Lambda_b^0\to D^0 p K^- and Λb0→Λc+K−\Lambda_b^0\to \Lambda_c^+ K^- are observed and their branching fractions are measured with respect to the decays Λb0→D0pπ−\Lambda_b^0\to D^0 p \pi^- and Λb0→Λc+π−\Lambda_b^0\to \Lambda_c^+ \pi^-. In addition, the first observation is reported of the decay of the neutral beauty-strange baryon Ξb0\Xi_b^0 to the D0pK−D^0 p K^- final state, and a measurement of the Ξb0\Xi_b^0 mass is performed. Evidence of the Ξb0→Λc+K−\Xi_b^0\to \Lambda_c^+ K^- decay is also reported

    Observation of associated production of a ZZ boson with a DD meson in the forward region

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    A search for associated production of a ZZ boson with an open charm meson is presented using a data sample, corresponding to an integrated luminosity of 1.0fb−11.0\mathrm{fb}^{-1} of proton--proton collisions at a centre-of-mass energy of 7 TeV, collected by the LHCb experiment. Seven candidate events for associated production of a ZZ boson with a D0D^0 meson and four candidate events for a ZZ boson with a D+D^+ meson are observed with a combined significance of 5.1 standard deviations. The production cross-sections in the forward region are measured to be σZ→Ό+ÎŒâˆ’â€‰âŁ,D0=2.50±1.12±0.22pb\sigma_{Z\rightarrow\mu^+\mu^-\!,D^0} = 2.50\pm1.12\pm0.22pb σZ→Ό+ÎŒâˆ’â€‰âŁ,D+=0.44±0.23±0.03pb,\sigma_{Z\rightarrow\mu^+\mu^-\!,D^+} = 0.44\pm0.23\pm0.03pb, where the first uncertainty is statistical and the second systematic

    Updated measurements of exclusive J/ψJ/\psi and ψ(2S)\psi(2S) production cross-sections in pppp collisions at s=7\sqrt{s}=7 TeV

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    The differential cross-section as a function of rapidity has been measured for the exclusive production of J/ψJ/\psi and ψ(2S)\psi(2S) mesons in proton-proton collisions at s=7\sqrt{s}=7 TeV, using data collected by the LHCb experiment, corresponding to an integrated luminosity of 930 pb−1^{-1}. The cross-sections times branching fractions to two muons having pseudorapidities between 2.0 and 4.5 are measured to be σpp→J/ψ→Ό+Ό−(2.0<ηΌ±<4.5)=291±7±19 pb,σpp→ψ(2S)→Ό+Ό−(2.0<ηΌ±<4.5)=6.5±0.9±0.4 pb,\begin{array}{rl} \sigma_{pp\rightarrow J/\psi\rightarrow{\mu^+}{\mu^-}}(2.0<\eta_{\mu^\pm }<4.5)=&291\pm 7\pm19 {\rm \ pb},\\ \sigma_{pp\rightarrow\psi(2S)\rightarrow{\mu^+}{\mu^-}}(2.0<\eta_{\mu^\pm}<4.5)=&6.5\pm 0.9\pm 0.4 {\rm \ pb},\end{array} where the first uncertainty is statistical and the second is systematic. The measurements agree with next-to-leading order QCD predictions as well as with models that include saturation effects.The differential cross-section as a function of rapidity has been measured for the exclusive production of J/ψJ/\psi and ψ(2S)\psi(2S) mesons in proton-proton collisions at s=7\sqrt{s}=7 TeV, using data collected by the LHCb experiment, corresponding to an integrated luminosity of 930 pb−1^{-1}. The cross-sections times branching fractions to two muons having pseudorapidities between 2.0 and 4.5 are measured to be σpp→J/ψ→Ό+Ό−(2.0<ηΌ±<4.5)=291±7±19 pb,σpp→ψ(2S)→Ό+Ό−(2.0<ηΌ±<4.5)=6.5±0.9±0.4 pb,\begin{array}{rl} \sigma_{pp\rightarrow J/\psi\rightarrow{\mu^+}{\mu^-}}(2.0<\eta_{\mu^\pm }<4.5)=&291\pm 7\pm19 {\rm \ pb},\\ \sigma_{pp\rightarrow\psi(2S)\rightarrow{\mu^+}{\mu^-}}(2.0<\eta_{\mu^\pm}<4.5)=&6.5\pm 0.9\pm 0.4 {\rm \ pb},\end{array} where the first uncertainty is statistical and the second is systematic. The measurements agree with next-to-leading order QCD predictions as well as with models that include saturation effects.The differential cross-section as a function of rapidity has been measured for the exclusive production of J/ψJ/\psi and ψ(2S)\psi(2S) mesons in proton-proton collisions at s=7\sqrt{s}=7 TeV, using data collected by the LHCb experiment, corresponding to an integrated luminosity of 930 pb−1^{-1}. The cross-sections times branching fractions to two muons having pseudorapidities between 2.0 and 4.5 are measured to be σpp→J/ψ→Ό+Ό−(2.0<ηΌ±<4.5)=291±7±19 pb,σpp→ψ(2S)→Ό+Ό−(2.0<ηΌ±<4.5)=6.5±0.9±0.4 pb,\begin{array}{rl} \sigma_{pp\rightarrow J/\psi\rightarrow{\mu^+}{\mu^-}}(2.0<\eta_{\mu^\pm }<4.5)=&291\pm 7\pm19 {\rm \ pb},\\ \sigma_{pp\rightarrow\psi(2S)\rightarrow{\mu^+}{\mu^-}}(2.0<\eta_{\mu^\pm}<4.5)=&6.5\pm 0.9\pm 0.4 {\rm \ pb},\end{array} where the first uncertainty is statistical and the second is systematic. The measurements agree with next-to-leading order QCD predictions as well as with models that include saturation effects

    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
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