Hasil untuk "Economics as a science"

M. Friedman, John Muth, R. Lucas et al.

LHCb collaboration, R. Aaij, A. S. W. Abdelmotteleb et al.

A study on the Bose-Einstein correlations for triplets of same-sign pions is presented. The analysis is performed using proton-proton collisions at a centre-of-mass energy of $\sqrt{s}$ = 7 TeV, recorded by the LHCb experiment, corresponding to an integrated luminosity of 1.0 fb$^{-1}$. For the first time, the results are interpreted in the core-halo model. The parameters of the model are determined in regions of charged-particle multiplicity. This measurement provides insight into the nature of hadronisation in terms of coherence, showing a coherent emission of pions.

LHCb collaboration, R. Aaij, A. S. W. Abdelmotteleb et al.

The observation of a wide peaking structure in the $B_{c}^{+} γ$ mass spectrum is reported using proton-proton collision data collected by the LHCb detector at center-of-mass energies of $7$, $8$, and $13~\text{TeV}$, corresponding to a total integrated luminosity of $9~\text{fb}^{-1}$. The statistical significance over the background-only hypothesis exceeds seven standard deviations. The width of the observed structure is larger than the expectation from a single-peak hypothesis, and is well described by an effective minimal model consisting of two narrow peaks located at $6704.8 \pm 5.5 \pm 2.8 \pm 0.3~\mathrm{Me\kern -0.1em V\!/}c^2$ and $6752.4 \pm 9.5 \pm 3.1 \pm 0.3~\mathrm{Me\kern -0.1em V\!/}c^2$. The uncertainty terms are statistical, systematic, and associated to the knowledge of the $B_{c}^{+}$ mass, respectively. The measured peak locations are in line with theoretical predictions for lowest excited $P$-wave $B_{c}^{+}$ states, marking the first observation of orbitally excited beauty-charm mesons and providing important insights into the internal dynamics of hadrons containing two heavy quarks.

LHCb collaboration, R. Aaij, A. S. W. Abdelmotteleb et al.

A study of the charmless baryonic decays $B^0_{(s)} \to K^0 p \bar{p}$ is presented, where $B^0_{(s)}$ denotes either a $B^0$ or a $B^0_s$ meson. The analysis is based on proton-proton collision data collected by the LHCb experiment at centre-of-mass energies of 7, 8, and $13~\mathrm{Tev}$, corresponding to an integrated luminosity of $9~\mathrm{fb}^{-1}$. The decay $B^0_s \to K^0 p \bar{p}$ is observed for the first time, with a measured branching fraction of $(9.14 \pm 1.69 \pm 0.90 \pm 0.33 \pm 0.20) \times 10^{-7}$ and a significance of $5.6σ$. The uncertainties respectively account for statistical and systematic contributions, the precision of the branching fraction of the normalisation channel $B^0 \to K^0 π^{+} π^{-}$ and the fragmentation fraction ratio ${f_s}/{f_d}$. The branching fraction determined for $B^0 \to K^0 p \bar{p}$ is $(2.82 \pm 0.08 \pm 0.12 \pm 0.10) \times 10^{-6}$, which is the most precise measurement to date.

LHCb collaboration, R. Aaij, A. S. W. Abdelmotteleb et al.

An analysis of the flavour oscillations of the charmed neutral meson is presented. The ratio of $D^{0} \to K^{+} π^{-}$ and $D^{0} \to K^{-} π^{+}$ decay rates is measured as a function of the decay time of the $D^{0}$ meson and compared with the charge-conjugated system to search for charge-parity violation. The meson flavour at production is double-tagged by the charges of the muon and pion in the preceding $\overline{B} \to D^{*}(2010)^{+} μ^{-} X$ and ${{D^{*}(2010)^{+}} \to D^{0}π^{+}}$ decays, respectively. These decays are selected from proton-proton collision data collected by the LHCb experiment at a centre-of-mass energy of ${13\,\text{TeV}}$ and corresponding to an integrated luminosity of ${5.4\,\text{fb}^{-1}}$. The flavour oscillation parameters, relating to the differences in mass and width of the mass eigenstates, are found to be ${y^\prime=(5.8\pm1.6)\times10^{-3}}$ and ${(x^\prime)^2=(0.0\pm1.2)\times10^{-4}}$. No evidence for charge-parity violation is seen either in the flavour oscillations or in the decay, where the direct charge-parity asymmetry is measured to be ${A_{D}=(2.3\pm1.7)\,{\%}}$.

LHCb collaboration, R. Aaij, A. S. W. Abdelmotteleb et al.

The transverse polarization of $Λ$ and $\barΛ$ hyperons is measured in $p$Pb collisions collected by the LHCb experiment at a nucleon-nucleon center-of-mass energy of $5.02$ TeV. The polarization is averaged over hyperon transverse momentum in the ranges $0.15 < p_{T} < 6.00 $ GeV/$c$, and Feynman-$x$ in the ranges $0.005 < x_{F} < 0.040$ (forward region) and $-0.10 < x_{F} < -0.01$ (backward region) defined relative to the proton beam direction. The transverse polarization is found to be compatible with zero for both $Λ$ and $\barΛ$ hyperons. The results are also measured as a function of $p_{T}$ and $x_{F}$ with no significant dependence on these variables observed. The results are compared with previous experimental measurements at different center-of-mass energies and collision environments.

LHCb collaboration, R. Aaij, A. S. W. Abdelmotteleb et al.

A first search for the lepton-flavour-violating decays $B^0\to K^{*0}τ^\pm e^\mp$ is presented. The analysis is performed using a sample of proton-proton collision data, collected with the LHCb detector at a centre-of-mass energy of 13 TeV between 2016 and 2018, corresponding to an integrated luminosity of 5.4 fb$^{-1}$. No significant signal is observed, and upper limits on the branching fractions are determined to be $\cal{B}$$(B^0 \to K^{*0}τ^-e^+)< 5.9$ $(7.1)\times 10^{-6}$ and $\cal{B}$$(B^0 \to K^{*0}τ^+e^-)< 4.9$ $(5.9)\times 10^{-6}$ at the 90% (95%) confidence level.

LHCb collaboration, R. Aaij, A. S. W. Abdelmotteleb et al.

The substructure of jets in quantum chromodynamics (QCD) has garnered significant attention with the advent of infrared- and collinear-safe clustering algorithms and observables. A key question emerging from these studies is how in-jet emissions at soft and hard energy scales, across collinear and wide angles relative to the emitter, differ with the mass of the emitting parton. The Lund jet plane (LJP) is a perturbatively well-defined substructure observable that maps the radiation pattern of jets onto a plane, visually distinguishing emissions with different kinematic properties. Comparing LJP for jets containing hadrons of low versus high mass enables the testing of QCD splitting functions from first-principles calculations across both soft and hard regimes and at different radiation angles. This article presents the first measurement of the LJP for light-quark-enriched and beauty-initiated jets at center-of-mass energy of 13\tev at LHCb. This marks the first direct observation of the dead-cone effect in beauty-quark jets, measured in the collinear region of the LJP.

LHCb collaboration, R. Aaij, A. S. W. Abdelmotteleb et al.

The LHCb collaboration presents a novel suite of heavy-flavour jet substructure measurements at forward rapidity in proton-proton collisions at a centre-of-mass energy of $\sqrt{s} = 13$ TeV. The jet mass is a perturbatively calculable probe of the virtuality of hard-scattered quarks and gluons, connecting small-distance quantum chromodynamics (QCD) with long-distance experimental measurement. It becomes dominated by nonperturbative corrections at small values, presenting an excellent test of QCD across a broad range of energies. Measuring heavy-flavour jet mass with a theoretically unambiguous flavour definition for the first time probes the gluon splitting mechanism for heavy-flavour production and pushes tests of perturbative QCD to unprecedented theoretical precision. Utilising the soft drop jet-grooming technique to access the perturbative jet core further enhances constraints on first-principles theory. Measurements of the jet mass for jets containing fully reconstructed $B^\pm$ hadrons are reported with and without grooming. These results offer unparalleled tests of quark flavour and mass dependence in QCD and provide a baseline for future studies of heavy-flavour jet quenching in heavy-ion collisions.

A. Goldberger, H. Blalock

Vitalii Vakulenko, Denys Smetan

У статті досліджено перспективні напрямки управління виробничими процесами сільськогосподарських підприємств з використанням блокчейн технологій в умовах забезпечення продовольчої безпеки. Визначено важливість блокчейн децентралізованої бази даних при зборі інформації при поставках виробників продуктів харчування, уточнено п’ять основних характеристик. Деталізовано способи використання блокчейн технологій. Представлено переваги від блокчейну з точки зору економії витрат задля більшої ефективності в існуючих процесах виробництва сільськогосподарської продукції. Уточнено чотири етапи реалізації блок-ланцюга в сільськогосподарських організаціях. Визначено основні переваги технології Blockchain: обмін продукцією без посередництва третьої сторони, безпека і надійність здійснюваних операцій, висока якість даних, робота з кваліфікованими користувачами, цілісність процесу, прозорість і незмінність системи, спрощена система обліку, ефективні транзакції.

M. G. Dubinina

The purpose of the study is to identify the impact of information and communication technologies and measures taken by telecommunications companies in China, Japan and South Korea on the environment of these countries.Materials and methods. Indexes of the ecological footprint (based on the Global Footprint Network data) and greenhouse gas emissions (based on the International Energy Agency data) for these countries are used as a measure of environmental assessment. Based on the Sustainability Reports of telecommunication companies in these countries (China Mobile, SK Telekom, KDDI and others), their strategies for environmental protection and achieving a zero carbon footprint are examined. The impact of information and communication technologies is assessed using indexes of the number of Internet users, fixed Internet access, mobile communications users per 100 people of the country’s population, the share of ICT goods and services in the total exports and imports of countries, as well as the growth index of IT investments in the private sector for Japan. For each country, a correlation matrix was constructed depending on the level of the logarithm of the ecological footprint (Y) on the logarithms of the listed indexes; the factors that most influence Y and are not multicollinear were selected. Based on the selected indexes, multiple regression models were developed for each country and their parameters were assessed.Results. For China and South Korea, a positive elasticity of the ecological footprint was obtained for the number of mobile phone users (for China) and fixed broadband Internet access (for South Korea). In addition, the import of ICT goods into a country reduces its environmental footprint, and the export of ICT services from the country leads to an increase in the index. For Japan, negative elasticities of the ICT sector indexes for the country’s ecological footprint were obtained, which is associated with measures taken by telecommunication companies to reduce their own consumption of electricity and other resources, as well as the widespread use of digital technologies for energy saving in other sectors of the Japanese economy.Conclusion. For China and South Korea, significant dependences of the country’s ecological footprint on the spread of digital technologies were obtained, and their diffusion entails an increase in the index. While this impact is not very large, the widespread adoption of 5G mobile communications in these countries should be taken into account, which could significantly increase the share of the ICT sector in the countries’ environmental footprint. At the same time, Japanese telecommunication companies are promoting environmental protection

LHCb collaboration, R. Aaij, A. S. W. Abdelmotteleb et al.

This paper presents the first measurement of $ψ{(2S)}$ and $χ_{c1}(3872)$ meson production within fully reconstructed jets. Each quarkonium state (tag) is reconstructed via its decay to the $J/ψ$($\rightarrowμ^+μ^-$)$π^+π^-$ final state in the forward region using proton-proton collision data collected by the LHCb experiment at the center-of-mass-energy of $13 \text{TeV}$ in 2016, corresponding to an integrated luminosity of $1.64 \text{fb}^{-1}$. The fragmentation function, presented as the ratio of the quarkonium-tag transverse momentum to the full jet transverse momentum ($p_{\mathrm{T}}(\text{tag})/p_{\mathrm{T}}(\text{jet})$), is measured differentially in $p_{\mathrm{T}}(\text{jet})$ and $p_{\mathrm{T}}(\text{tag})$ bins. The distributions are separated into promptly produced quarkonia from proton-proton collisions and quarkonia produced from displaced $b$-hadron decays. While the displaced quarkonia fragmentation functions are in general well described by parton-shower predictions, the prompt quarkonium distributions differ significantly from fixed-order non-relativistic QCD (NRQCD) predictions followed by a QCD parton shower.

LHCb collaboration, R. Aaij, A. S. W. Abdelmotteleb et al.

The ratio of branching fractions between $B^{0} \rightarrow J/ψπ^{0}$ and $B^{+} \rightarrow J/ψK^{*+}$ decays is measured with proton-proton collision data collected by the LHCb experiment, corresponding to an integrated luminosity of 9 fb$^{-1}$. The measured value is $\frac{\mathcal{B}_{B^{0} \rightarrow J/ψπ^{0}}}{\mathcal{B}_{B^{+} \rightarrow J/ψK^{*+}}} = (1.153 \pm 0.053 \pm 0.048 ) \times 10^{-2}$, where the first uncertainty is statistical and the second is systematic. The branching fraction for $B^{0} \rightarrow J/ψπ^{0}$ decays is determined using the branching fraction of the normalisation channel, resulting in $\mathcal{B}_{B^{0} \rightarrow J/ψπ^{0}} = (1.670 \pm 0.077 \pm 0.069 \pm 0.095) \times 10^{-5}$, where the last uncertainty corresponds to that of the external input. This result is consistent with the current world average value and competitive with the most precise single measurement to date.

LHCb collaboration, R. Aaij, A. S. W. Abdelmotteleb et al.

The resonant structure of the radiative decay $Λ_b^0\to pK^-γ$ in the region of proton-kaon invariant-mass up to 2.5 GeV$/c^2$ is studied using proton-proton collision data recorded at centre-of-mass energies of 7, 8, and 13 TeV collected with the LHCb detector, corresponding to a total integrated luminosity of 9 fb$^{-1}$. Results are given in terms of fit and interference fractions between the different components contributing to this final state. Only $Λ$ resonances decaying to $pK^-$ are found to be relevant, where the largest contributions stem from the $Λ(1520)$, $Λ(1600)$, $Λ(1800)$, and $Λ(1890)$ states.

LHCb collaboration, R. Aaij, A. S. W. Abdelmotteleb et al.

Measurements are presented of the cross-section for the central exclusive production of $J/ψ\toμ^+μ^-$ and $ψ(2S)\toμ^+μ^-$ processes in proton-proton collisions at $\sqrt{s} = 13 $ TeV with 2016-2018 data. They are performed by requiring both muons to be in the LHCb acceptance (with pseudorapidity $2<η_{μ^\pm} < 4.5$) and mesons in the rapidity range $2.0 < y < 4.5$. The integrated cross-section results are \begin{equation*} σ_{J/ψ\toμ^+μ^-}(2.0<y_{J/ψ}<4.5,2.0<η_{μ^\pm} < 4.5) = 400 \pm 2 \pm 5 \pm 12 \,{\rm pb}\,, \end{equation*} \begin{equation*} σ_{ψ(2S)\toμ^+μ^-}(2.0<y_{ψ(2S)}<4.5,2.0<η_{μ^\pm} < 4.5) = 9.40 \pm 0.15 \pm 0.13 \pm 0.27 \,{\rm pb}\,, \end{equation*} where the uncertainties are statistical, systematic and due to the luminosity determination. In addition, a measurement of the ratio of $ψ(2S)$ and $J/ψ$ cross-sections, at an average photon-proton centre-of-mass energy of 1 TeV, is performed, giving \begin{equation*} \frac{σ_{ψ(2S)}}{σ_{J/ψ}} = 0.1763 \pm 0.0029 \pm 0.0008 \pm 0.0039 \,, \end{equation*} where the first uncertainty is statistical, the second systematic and the third due to the knowledge of the involved branching fractions. For the first time, the dependence of the $J/ψ$ and $ψ(2S)$ cross-sections on the total transverse momentum transfer is determined in $pp$ collisions and is found consistent with the behaviour observed in electron-proton collisions.

LHCb collaboration, R. Aaij, A. S. W. Abdelmotteleb et al.

Decays of $\mathitΞ_{b}^-$ and $\mathitΩ_{b}^-$ baryons to $\mathitΛ_{c}^+ h^- h^{\prime -}$ final states, with $h^- h^{\prime -}$ being $π^-π^-$, $K^-π^-$ and $K^-K^-$ meson pairs, are searched for using data collected with the LHCb detector. The data sample studied corresponds to an integrated luminosity of $8.7\,\mathrm{fb}^{-1}$ of $pp$ collisions collected at centre-of-mass energies $\sqrt{s} = 7$, $8$ and $13\,\mathrm{Te\kern -0.1em V}$. The products of the relative branching fractions and fragmentation fractions for each signal mode, relative to the $B^- \to \mathitΛ_{c}^+ \overline{p} π^-$ mode, are measured, with $\mathitΞ_{b}^- \to\mathitΛ_{c}^+ K^- π^-$, $\mathitΞ_{b}^- \to\mathitΛ_{c}^+ K^- K^-$ and $\mathitΩ_{b}^- \to\mathitΛ_{c}^+ K^- K^-$ decays being observed at over $5\,σ$ significance. The $\mathitΞ_{b}^- \to\mathitΛ_{c}^+ K^- π^-$ mode is also used to measure the $\mathitΞ_{b}^-$ production asymmetry, which is found to be consistent with zero. In addition, the $B^- \to \mathitΛ_{c}^+ \overline{p} K^-$ decay is observed for the first time, and its branching fraction is measured relative to that of the $B^- \to \mathitΛ_{c}^+ \overline{p} π^-$ mode.

LHCb collaboration, R. Aaij, A. S. W. Abdelmotteleb et al.

The first test of lepton flavor universality between muons and electrons using $B^+ \to K^+π^+π^-\ell^+\ell^-$ ($\ell=e,μ$) decays is presented. The measurement is performed with data from proton-proton collisions collected by the LHCb experiment at center-of-mass energies of 7, 8, and 13 TeV, corresponding to an integrated luminosity of $9\mathrm{fb}^{-1}$. The ratio of branching fractions between $B^+ \to K^+π^+π^-e^+e^-$ and $B^+ \to K^+π^+π^-μ^+μ^-$decays is measured in the dilepton invariant-mass-squared range $1.1 < q^2 < 7.0~\mathrm{GeV}^2/c^4$ and is found to be $R_{Kππ}^{-1} = 1.31^{+0.18}_{-0.17} \;(\mathrm{stat})\;^{+0.12}_{-0.09} \;(\mathrm{syst})$, in agreement with the standard model prediction. The first observation of the $B^+ \to K^+π^+π^-e^+e^-$ decay is also reported.

LHCb collaboration, R. Aaij, A. S. W. Abdelmotteleb et al.

The differential branching fraction and angular coefficients of $\itΛ^\mathrm{0}_b \rightarrow pK^-μ^+μ^-$ decays are measured in bins of the dimuon mass squared and dihadron mass. The analysis is performed using a data set corresponding to 9$\text{fb}^{-1}$ of integrated luminosity collected with the $\mbox{LHCb}$ detector between 2011 and 2018. The data are consistent with receiving contributions from a mixture of $\itΛ$ resonances with different spin-parity quantum numbers. The angular coefficients show a pattern of vector-axial vector interference that is a characteristic of the type of flavour-changing neutral-current transition relevant for these decays.

Jamie C Tam, Courtenay E. Parlee, Jill Campbell-Miller et al.

Understanding social-ecological systems (SESs) is an important part of ecosystem-based management (EBM). One of the main decision support frameworks to develop scientific advice for EBM is integrated ecosystem assessments (IEAs). Human dimensions in SESs are primarily captured through indicators derived from three social sciences: economics, anthropology, and sociology. The breadth of social sciences and humanities (SSH) research is much greater than those three fields, but they are generally underused in natural science-based decision support processes such as IEAs. Greater contributions of SSHs can enhance IEAs through various direct (e.g. to develop indicators) and indirect ways (e.g. to establish and maintain ethical practices). We examine a wider range of SSH disciplines and conclude that scientific advice processes that inform EBM can benefit from broader integration of SSH theories and methods through themes of contextualizing, facilitating, communicating, evaluating, and anticipating. We see this an opportunity to both widen the vocabulary used to describe social scientists and those who work in humanities in IEAs, and apply the underlying worldviews used to conduct SSH research to fundamentally enhance the IEA process and to further progress in EBM.