74 research outputs found

    COMPARATIVE ANALYSIS ОF DIFFERENT PLANTS UTILIZING COLD ENERGY OF LIQUID NATURAL GAS

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    This article deals with comparative analysis of the energy plants, utilizing cold energy of liquid natural gas. Comparative analysis require development of certain criteria which must take into account generated energy, degree of liquid natural gas cold energy utilization etc. Analysis shows that one of the most effective ways to utilize cold energy is thermal compression

    Search for the doubly heavy baryon Ξbc+\it{\Xi}_{bc}^{+} decaying to J/ψΞc+J/\it{\psi} \it{\Xi}_{c}^{+}

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    A first search for the Ξbc+J/ψΞc+\it{\Xi}_{bc}^{+}\to J/\it{\psi}\it{\Xi}_{c}^{+} decay is performed by the LHCb experiment with a data sample of proton-proton collisions, corresponding to an integrated luminosity of 9fb19\,\mathrm{fb}^{-1} recorded at centre-of-mass energies of 7, 8, and 13TeV13\mathrm{\,Te\kern -0.1em V}. Two peaking structures are seen with a local (global) significance of 4.3(2.8)4.3\,(2.8) and 4.1(2.4)4.1\,(2.4) standard deviations at masses of 6571MeV ⁣/c26571\,\mathrm{Me\kern -0.1em V\!/}c^2 and 6694MeV ⁣/c26694\,\mathrm{Me\kern -0.1em V\!/}c^2, respectively. Upper limits are set on the Ξbc+\it{\Xi}_{bc}^{+} baryon production cross-section times the branching fraction relative to that of the Bc+J/ψDs+B_{c}^{+}\to J/\it{\psi} D_{s}^{+} decay at centre-of-mass energies of 8 and 13TeV13\mathrm{\,Te\kern -0.1em V}, in the Ξbc+\it{\Xi}_{bc}^{+} and in the Bc+B_{c}^{+} rapidity and transverse-momentum ranges from 2.0 to 4.5 and 0 to 20GeV ⁣/c20\,\mathrm{Ge\kern -0.1em V\!/}c, respectively. Upper limits are presented as a function of the Ξbc+\it{\Xi}_{bc}^{+} mass and lifetime.Comment: All figures and tables, along with machine-readable versions and any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-005.html (LHCb public pages

    Measurement of CP asymmetries and branching fraction ratios of B− decays to two charm mesons

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    The CPCP asymmetries of seven BB^- decays to two charm mesons are measured using data corresponding to an integrated luminosity of 9fb19\text{fb}^{-1} of proton-proton collisions collected by the LHCb experiment. Decays involving a D0D^{*0} or DsD^{*-}_s meson are analysed by reconstructing only the D0D^0 or DsD^-_s decay products. This paper presents the first measurement of ACP(BDsD0)\mathcal{A}^{CP}(B^- \rightarrow D^{*-}_s D^0) and ACP(BDsD0)\mathcal{A}^{CP}(B^- \rightarrow D^{-}_s D^{*0}), and the most precise measurement of the other five CPCP asymmetries. There is no evidence of CPCP violation in any of the analysed decays. Additionally, two ratios between branching fractions of selected decays are measured.The CP asymmetries of seven B^{−} decays to two charm mesons are measured using data corresponding to an integrated luminosity of 9 fb1^{−1} of proton-proton collisions collected by the LHCb experiment. Decays involving a D0^{*0} or Ds {D}_s^{\ast -} meson are analysed by reconstructing only the D0^{0} or Ds {D}_s^{-} decay products. This paper presents the first measurement of ACP \mathcal{A} ^{CP}(B^{−}Ds {D}_s^{\ast -} D0^{0}) and ACP \mathcal{A} ^{CP}(B^{−}Ds {D}_s^{-} D0^{∗0}), and the most precise measurement of the other five CP asymmetries. There is no evidence of CP violation in any of the analysed decays. Additionally, two ratios between branching fractions of selected decays are measured.[graphic not available: see fulltext]The CPCP asymmetries of seven BB^- decays to two charm mesons are measured using data corresponding to an integrated luminosity of 9 fb19\text{ fb}^{-1} of proton-proton collisions collected by the LHCb experiment. Decays involving a D0D^{*0} or DsD^{*-}_s meson are analysed by reconstructing only the D0D^0 or DsD^-_s decay products. This paper presents the first measurement of ACP(BDsD0)\mathcal{A}^{CP}(B^- \rightarrow D^{*-}_s D^0) and ACP(BDsD0)\mathcal{A}^{CP}(B^- \rightarrow D^{-}_s D^{*0}), and the most precise measurement of the other five CPCP asymmetries. There is no evidence of CPCP violation in any of the analysed decays. Additionally, two ratios between branching fractions of selected decays are measured

    Helium identification with LHCb

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    The identification of helium nuclei at LHCb is achieved using a method based on measurements of ionisation losses in the silicon sensors and timing measurements in the Outer Tracker drift tubes. The background from photon conversions is reduced using the RICH detectors and an isolation requirement. The method is developed using pp collision data at √(s) = 13 TeV recorded by the LHCb experiment in the years 2016 to 2018, corresponding to an integrated luminosity of 5.5 fb-1. A total of around 105 helium and antihelium candidates are identified with negligible background contamination. The helium identification efficiency is estimated to be approximately 50% with a corresponding background rejection rate of up to O(10^12). These results demonstrate the feasibility of a rich programme of measurements of QCD and astrophysics interest involving light nuclei

    Curvature-bias corrections using a pseudomass method

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    Momentum measurements for very high momentum charged particles, such as muons from electroweak vector boson decays, are particularly susceptible to charge-dependent curvature biases that arise from misalignments of tracking detectors. Low momentum charged particles used in alignment procedures have limited sensitivity to coherent displacements of such detectors, and therefore are unable to fully constrain these misalignments to the precision necessary for studies of electroweak physics. Additional approaches are therefore required to understand and correct for these effects. In this paper the curvature biases present at the LHCb detector are studied using the pseudomass method in proton-proton collision data recorded at centre of mass energy √(s)=13 TeV during 2016, 2017 and 2018. The biases are determined using Z→μ + μ - decays in intervals defined by the data-taking period, magnet polarity and muon direction. Correcting for these biases, which are typically at the 10-4 GeV-1 level, improves the Z→μ + μ - mass resolution by roughly 18% and eliminates several pathological trends in the kinematic-dependence of the mean dimuon invariant mass

    Study of the lineshape of the chi(c1) (3872) state

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    A study of the lineshape of the chi(c1) (3872) state is made using a data sample corresponding to an integrated luminosity of 3 fb(-1) collected in pp collisions at center-of-mass energies of 7 and 8 TeV with the LHCb detector. Candidate chi(c1)(3872) and psi(2S) mesons from b-hadron decays are selected in the J/psi pi(+)pi(-) decay mode. Describing the lineshape with a Breit-Wigner function, the mass splitting between the chi(c1 )(3872) and psi(2S) states, Delta m, and the width of the chi(c1 )(3872) state, Gamma(Bw), are determined to be (Delta m=185.598 +/- 0.067 +/- 0.068 Mev,)(Gamma BW=1.39 +/- 0.24 +/- 0.10 Mev,) where the first uncertainty is statistical and the second systematic. Using a Flatte-inspired model, the mode and full width at half maximum of the lineshape are determined to be (mode=3871.69+0.00+0.05 MeV.)(FWHM=0.22-0.04+0.13+0.07+0.11-0.06-0.13 MeV, ) An investigation of the analytic structure of the Flatte amplitude reveals a pole structure, which is compatible with a quasibound D-0(D) over bar*(0) state but a quasivirtual state is still allowed at the level of 2 standard deviations

    Measurement of the CKM angle γγ in B±DK±B^\pm\to D K^\pm and B±Dπ±B^\pm \to D π^\pm decays with DKS0h+hD \to K_\mathrm S^0 h^+ h^-

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    A measurement of CPCP-violating observables is performed using the decays B±DK±B^\pm\to D K^\pm and B±Dπ±B^\pm\to D \pi^\pm, where the DD meson is reconstructed in one of the self-conjugate three-body final states KSπ+πK_{\mathrm S}\pi^+\pi^- and KSK+KK_{\mathrm S}K^+K^- (commonly denoted KSh+hK_{\mathrm S} h^+h^-). The decays are analysed in bins of the DD-decay phase space, leading to a measurement that is independent of the modelling of the DD-decay amplitude. The observables are interpreted in terms of the CKM angle γ\gamma. Using a data sample corresponding to an integrated luminosity of 9fb19\,\text{fb}^{-1} collected in proton-proton collisions at centre-of-mass energies of 77, 88, and 13TeV13\,\text{TeV} with the LHCb experiment, γ\gamma is measured to be (68.75.1+5.2)\left(68.7^{+5.2}_{-5.1}\right)^\circ. The hadronic parameters rBDKr_B^{DK}, rBDπr_B^{D\pi}, δBDK\delta_B^{DK}, and δBDπ\delta_B^{D\pi}, which are the ratios and strong-phase differences of the suppressed and favoured B±B^\pm decays, are also reported

    The Vortex Aircooler System for Cutting Materials in Aerospace Industry

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    In aerospace industry there is a situation, when it is not possible to use liquid cooling of cutting zone, because we have special material or special construction. How often in that case used air fluent, but it has some problems with life cycle tools, quality and cutting time. For solving these problems was use the vortex effect, it was open less than one hundred years ago. The unit for making vortex effect is could vortex tube. It was done the design the vortex tube of air cooler system for cutting using some researching [1-5]. Some experimental dates gave verification. The construction was made by metal materials and now is using on JSC «Salut», Samara.
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