10 research outputs found

    Study of the production of Λb0\Lambda_b^0 and B‟0\overline{B}^0 hadrons in pppp collisions and first measurement of the Λb0→J/ψpK−\Lambda_b^0\rightarrow J/\psi pK^- branching fraction

    Get PDF
    The product of the Λb0\Lambda_b^0 (B‟0\overline{B}^0) differential production cross-section and the branching fraction of the decay Λb0→J/ψpK−\Lambda_b^0\rightarrow J/\psi pK^- (B‟0→J/ψK‟∗(892)0\overline{B}^0\rightarrow J/\psi\overline{K}^*(892)^0) is measured as a function of the beauty hadron transverse momentum, pTp_{\rm T}, and rapidity, yy. The kinematic region of the measurements is pT<20 GeV/cp_{\rm T}<20~{\rm GeV}/c and 2.0<y<4.52.0<y<4.5. The measurements use a data sample corresponding to an integrated luminosity of 3 fb−13~{\rm fb}^{-1} collected by the LHCb detector in pppp collisions at centre-of-mass energies s=7 TeV\sqrt{s}=7~{\rm TeV} in 2011 and s=8 TeV\sqrt{s}=8~{\rm TeV} in 2012. Based on previous LHCb results of the fragmentation fraction ratio, fΛB0/fdf_{\Lambda_B^0}/f_d, the branching fraction of the decay Λb0→J/ψpK−\Lambda_b^0\rightarrow J/\psi pK^- is measured to be \begin{equation*} \mathcal{B}(\Lambda_b^0\rightarrow J/\psi pK^-)= (3.17\pm0.04\pm0.07\pm0.34^{+0.45}_{-0.28})\times10^{-4}, \end{equation*} where the first uncertainty is statistical, the second is systematic, the third is due to the uncertainty on the branching fraction of the decay B‟0→J/ψK‟∗(892)0\overline{B}^0\rightarrow J/\psi\overline{K}^*(892)^0, and the fourth is due to the knowledge of fΛb0/fdf_{\Lambda_b^0}/f_d. The sum of the asymmetries in the production and decay between Λb0\Lambda_b^0 and Λ‟b0\overline{\Lambda}_b^0 is also measured as a function of pTp_{\rm T} and yy. The previously published branching fraction of Λb0→J/ψpπ−\Lambda_b^0\rightarrow J/\psi p\pi^-, relative to that of Λb0→J/ψpK−\Lambda_b^0\rightarrow J/\psi pK^-, is updated. The branching fractions of Λb0→Pc+(→J/ψp)K−\Lambda_b^0\rightarrow P_c^+(\rightarrow J/\psi p)K^- are determined.Comment: 29 pages, 19figures. All figures and tables, along with any supplementary material and additional information, are available at https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-032.htm

    Measurements of long-range near-side angular correlations in sNN=5\sqrt{s_{\text{NN}}}=5TeV proton-lead collisions in the forward region

    Get PDF
    Two-particle angular correlations are studied in proton-lead collisions at a nucleon-nucleon centre-of-mass energy of sNN=5\sqrt{s_{\text{NN}}}=5TeV, collected with the LHCb detector at the LHC. The analysis is based on data recorded in two beam configurations, in which either the direction of the proton or that of the lead ion is analysed. The correlations are measured in the laboratory system as a function of relative pseudorapidity, Δη\Delta\eta, and relative azimuthal angle, Δϕ\Delta\phi, for events in different classes of event activity and for different bins of particle transverse momentum. In high-activity events a long-range correlation on the near side, Δϕ≈0\Delta\phi \approx 0, is observed in the pseudorapidity range 2.0<η<4.92.0<\eta<4.9. This measurement of long-range correlations on the near side in proton-lead collisions extends previous observations into the forward region up to η=4.9\eta=4.9. The correlation increases with growing event activity and is found to be more pronounced in the direction of the lead beam. However, the correlation in the direction of the lead and proton beams are found to be compatible when comparing events with similar absolute activity in the direction analysed.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-040.htm

    Evidence for the strangeness-changing weak decay Ξb−→Λb0π−\Xi_b^-\to\Lambda_b^0\pi^-

    Get PDF
    Using a pppp collision data sample corresponding to an integrated luminosity of 3.0~fb−1^{-1}, collected by the LHCb detector, we present the first search for the strangeness-changing weak decay Ξb−→Λb0π−\Xi_b^-\to\Lambda_b^0\pi^-. No bb hadron decay of this type has been seen before. A signal for this decay, corresponding to a significance of 3.2 standard deviations, is reported. The relative rate is measured to be fΞb−fΛb0B(Ξb−→Λb0π−)=(5.7±1.8−0.9+0.8)×10−4{{f_{\Xi_b^-}}\over{f_{\Lambda_b^0}}}{\cal{B}}(\Xi_b^-\to\Lambda_b^0\pi^-) = (5.7\pm1.8^{+0.8}_{-0.9})\times10^{-4}, where fΞb−f_{\Xi_b^-} and fΛb0f_{\Lambda_b^0} are the b→Ξb−b\to\Xi_b^- and b→Λb0b\to\Lambda_b^0 fragmentation fractions, and B(Ξb−→Λb0π−){\cal{B}}(\Xi_b^-\to\Lambda_b^0\pi^-) is the branching fraction. Assuming fΞb−/fΛb0f_{\Xi_b^-}/f_{\Lambda_b^0} is bounded between 0.1 and 0.3, the branching fraction B(Ξb−→Λb0π−){\cal{B}}(\Xi_b^-\to\Lambda_b^0\pi^-) would lie in the range from (0.57±0.21)%(0.57\pm0.21)\% to (0.19±0.07)%(0.19\pm0.07)\%.Comment: 7 pages, 2 figures, All figures and tables, along with any supplementary material and additional information, are available at https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-047.htm

    Model-independent measurement of mixing parameters in D0^{0} → KS0_{S}^{0} π+^{+}π−^{−} decays

    Get PDF
    The first model-independent measurement of the charm mixing parameters in the decay D0→KSπ+π−D^0 \to K_S \pi^+ \pi^- is reported, using a sample of pppp collision data recorded by the LHCb experiment, corresponding to an integrated luminosity of 1.0 fb−1^{-1} at a centre-of-mass energy of 7 TeV. The measured values are \begin{eqnarray*} x &=& (-0.86 \pm 0.53 \pm 0.17) \times 10^{-2}, \\ y &=& (+0.03 \pm 0.46 \pm 0.13) \times 10^{-2}, \end{eqnarray*} where the first uncertainties are statistical and include small contributions due to the external input for the strong phase measured by the CLEO collaboration, and the second uncertainties are systematic.Comment: 25 pages, 3 figures. Sign error in x fixed as of v2. All figures and tables, along with any supplementary material and additional information, are available at https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-042.htm

    A precise measurement of the B0B^0 meson oscillation frequency

    Get PDF
    The oscillation frequency, Δmd\Delta m_d, of B0B^0 mesons is measured using semileptonic decays with a D−D^- or D∗−D^{*-} meson in the final state, in a data sample of pppp collisions collected by the LHCb detector corresponding to an integrated luminosity of 3.0\mbox{fb}^{-1}. A combination of the two decay modes gives Δmd=(505.0±2.1±1.0) ns−1\Delta m_d = (505.0 \pm 2.1 \pm 1.0) \rm \,ns^{-1}, where the first uncertainty is statistical and the second is systematic. This is the most precise single measurement of this parameter. It is compatible with the current world average and has similar precision.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-031.htm

    Dissociative recombination and excitation of H2O+ and HDO+

    Get PDF
    Dissociative recombination and excitation of H2O+ and HDO+ in the vibrational ground state have been studied at the heavy-ion storage ring ASTRID. Absolute cross sections have been measured in the energy range from similar to 0.1 meV to similar to 50 eV. The total cross sections for dissociative recombination are essentially the same for the two molecular ions. Complete branching ratios for all possible product channels in dissociative recombination at E = 0 have been determined. Three-particle breakup accounts for similar to 60% of the recombination events. With HDO+,recombination into OD + H is twice as probable as recombination into OH+D. An isotope effect is also evident in the cross sections for dissociative excitation of HDO+, where H+ production is more likely than D+ production. [S1050-2947(99)01910-1]

    Rekruttering til kirkelige stillinger. En undersÞkelse blant studenter pÄ studier som kvalifiserer til jobb som prest, kateket, diakon eller kirkemusiker

    Get PDF
    Rekruttering til alle kirkelige stillinger (prest, diakon, kirkemusiker, kateket og andre undervisningsstillinger er i dag en stor utfordring i Den norske kirke (Dnk). Prognoser viser at det er for fÄ som utdanner seg til kirkelig tjeneste i forhold til behovene. Det er satt i gang flere tiltak med tanke pÄ rekruttering til Dnk, men det er gjort lite forskning pÄ feltet

    Observation of Λb0→ψ(2S)pK− \Lambda_b^0 \to \psi(2S)pK^- and Λb0→J/ψπ+π−pK− \Lambda_b^0 \to J/\psi \pi^+ \pi^- pK^- decays and a measurement of the Λb0\Lambda_b^0 baryon mass

    Get PDF
    20 pages, 4 figures. All figures and tables, along with any supplementary material and additional information, are available at https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-060.htmlInternational audienceThe decays Λb0→ψ(2S)pK− \Lambda_b^0 \to \psi(2S)pK^- and Λb0→J/ψπ+π−pK− \Lambda_b^0 \to J/\psi \pi^+ \pi^- pK^- are observed in a data sample corresponding to an integrated luminosity of 3fb−1^{-1}, collected in proton-proton collisions at 7 and 8TeV centre-of-mass energies by the LHCb detector. The ψ(2S)\psi(2S) mesons are reconstructed through the decay modes ψ(2S)→Ό+Ό−\psi(2S)\to\mu^+\mu^- and ψ(2S)→J/ψπ+π−\psi(2S)\to J/\psi\pi^+\pi^-. The branching fractions relative to that of Λb0→J/ψpK− \Lambda_b^0 \to J/\psi pK^- are measured to be \begin{eqnarray*} \frac{\mathcal{B}(\Lambda_b^0 \to \psi(2S) pK^-)} {\mathcal{B}(\Lambda_b^0 \to J/\psi pK^-)} & = & (20.70\pm 0.76\pm 0.46\pm 0.37)\times10^{-2} \,, \frac{\mathcal{B}(\Lambda_b^0 \to J/\psi \pi^+ \pi^- pK^-)} {\mathcal{B}(\Lambda_b^0 \to J/\psi pK^-)} & = & (20.86\pm 0.96\pm 1.34)\times10^{-2} \,, \end{eqnarray*} where the first uncertainties are statistical, the second are systematic and the third is related to the knowledge of J/ψJ/\psi and ψ(2S)\psi(2S) branching fractions. The mass of the Λb0\Lambda_b^0 baryon is measured to be M(Λb0)=5619.65±0.17±0.17MeV/c2, M(\Lambda_b^0) = 5619.65 \pm 0.17 \pm 0.17\mathrm{MeV}/c^2, where the uncertainties are statistical and systematic

    High standard detached house

    Get PDF
    The bachelor’s thesis is handeling project documentation of high standard detached house. House is two-storey high. It is suited for four to six-member family. Detached house is rectangular shaped with two fitting rectangulars and it is roofed by flat roof. The roof above garage and kitchen with dining room is designed like terrace. It is open from second floor

    Wohnsituation Alleinerziehender Materialien zu einem Forschungsfeld des Experimentellen Wohnungs- und Staedtebaus 'Wohnsituation Alleinerziehender und alleinstehender Schwangerer in Notlage'

    Get PDF
    UuStB Koeln(38)-930106270 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman
    corecore