2,299 research outputs found

    Comment on `Note on X(3872) production at hadron colliders and its molecular structure'

    Get PDF
    We briefly comment on the paper by Albaladejo et al. [arXiv:1709.09101], rejecting its conclusions.Comment: This paper was prepared at the request of a journal editor. 3 Pages, no figure

    Understanding the interaction between cyclists and automated vehicles: Results from a cycling simulator study

    Get PDF
    Cycling as an active mode of transport is increasing across all Europe [1]. Multiple benefits are coming from cycling both for the single user and the society as a whole. With increasing cycling, we expect more conflicts to happen between cyclists and vehicles, as it is also shown by the increasing cyclists' share of fatalities, contrary to the passenger cars' share [2]. Understanding cyclists' behavioral patterns can help automated vehicles (AVs) to predict cyclist's behavior, and then behave safely and comfortably when they encounter them. As a result, developing reliable predictive models of cyclist behavior will help AVs to interact safely with cyclists

    Strong Couplings of X(3872)_{J=1,2} and a New Look at J/psi Suppression in Heavy Ion Collisions

    Full text link
    We define and compute from data the strong couplings of the X(3872) with both of the possible quantum numbers assignments J^{PC}=1^{++},2^{-+}. We use these to compute cross sections for J/psi resonance scattering into D Dbar*. As an application of the results obtained we revise the calculation of the J/psi absorption in a hot hadron gas to confront with recent RHIC observations in Au-Au collisions.Comment: 23 pages, 18 figures, 4 table

    Quartic anomalous couplings at LEP

    Get PDF
    The search for quartic anomalous gauge couplings at LEP requires appropriate predictions for the radiative processes e+ e- \to \nu\bar\nu \gamma\gamma, e+ e- \to q\bar{q}\gamma\gamma and e+ e- \to 4 fermions+\gamma. Matrix elements are exactly computed at the tree level, and the effects of anomalous couplings and initial-state radiation are included. Comparisons with results and approximations existing in the literature are shown and commented. Improved versions of the event generators NUNUGPV and WRAP are made available for experimental analysis.Comment: LaTeX, 12 pages, 5 figures. Minor changes, version to appear in Phys. Lett.

    A new digital divide threatening resilience: exploring the need for educational, firm-based, and societal investments in ICT human capital

    Get PDF
    The knowledge, skills, and abilities that human capital offers create tangible and intangible assets that equip organizations to thrive. In particular, in today’s Industry 4.0 environment, training, recruiting, and retaining highly qualified ICT-ready professionals remains a problem for many organizations including educational, governmental, healthcare, and business organizations. The COVID-19 pandemic revealed the importance of digital assets to our economies, and it is also demonstrating that there is potentially a new digital divide with even worse implications for companies, economies, and society, which is threatening the resilience of business, governance, and society. In this paper, we respond to the question “how can we develop ICT human capital in our global economy in an equitable, inclusive, and purposeful manner such that not organizations thrive, but also to promote social justice and equity in our global economy?”

    Electronic, optical and thermal properties of the hexagonal and fcc Ge2Sb2Te5 chalcogenide from first-principle calculations

    Full text link
    We present a comprehensive computational study on the properties of face-centered cubic and hexagonal chalcogenide Ge2Sb2Te5. We calculate the electronic structure using density functional theory (DFT); the obtained density of states (DOS) compares favorably with experiments, also looking suitable for transport analysis. Optical constants including refraction index and absorption coefficient capture major experimental features, aside from an energy shift owed to an underestimate of the band gap that is typical of DFT calculations. We also compute the phonon DOS for the hexagonal phase, obtaining a speed of sound and thermal conductivity in good agreement with the experimental lattice contribution. The calculated heat capacity reaches ~ 1.4 x 106 J/(m3 K) at high temperature, in agreement with experimental data, and provides insight into the low-temperature range (< 150 K), where data are unavailable.Comment: 19 pages, 8 figure

    Single-photon signal from neutralinos at LEP2

    Get PDF
    The production of invisible pairs of lightest neutralinos accompanied by a large-angle hard photon in the reaction e+eχ10χ10γe^+ e^- \to \chi^0_1 \chi^0_1 \gamma is studied at LEP2 energies. The most general gaugino/higgsino composition of the χ10\chi^0_1 within the Minimal Supersymmetric Standard Model is assumed. The spectrum of the observed photon is derived within the framework of the ptp_t-dependent structure-function approach, whose accuracy is assessed to be within the foreseen experimental accuracy at LEP2. Higher-order QED corrections due to undetected initial-state radiation are also included. A comparison with the Standard Model main background from e+eννˉγe^+ e^- \to \nu \bar \nu \gamma is performed for optimized photon kinematical cuts. Quantitative conclusions on the signal/background ratio are given for a wide range of values of the SUSY parameters.Comment: 19 pages, 6 figures, uuencoded gzipped postscript file. Revised (->shortened) version. To be published in Nuclear Physics

    A combined experimental and computational study of the pressure dependence of the vibrational spectrum of solid picene C_22H_14

    Full text link
    We present high-quality optical data and density functional perturbation theory calculations for the vibrational spectrum of solid picene (C22_{22}H14_{14}) under pressure up to 8 GPa. First-principles calculations reproduce with a remarkable accuracy the pressure effects on both frequency and intensities of the phonon peaks experimentally observed . Through a detailed analysis of the phonon eigenvectors, We use the projection on molecular eigenmodes to unambiguously fit the experimental spectra, resolving complicated spectral structures, in a system with hundreds of phonon modes. With these projections, we can also quantify the loss of molecular character under pressure. Our results indicate that picene, despite a \sim 20 % compression of the unit cell, remains substantially a molecular solid up to 8 GPa, with phonon modes displaying a smooth and uniform hardening with pressure. The Grueneisen parameter of the 1380 cm^{-1} a_1 Raman peak (γp=0.1\gamma_p=0.1) is much lower than the effective value (γd=0.8\gamma_d=0.8) due to K doping. This is an indication that the phonon softening in K doped samples is mainly due to charge transfer and electron-phonon coupling.Comment: Replaced with final version (PRB

    Making a few talk for the many – Modeling driver behavior using synthetic populations generated from experimental data

    Get PDF
    Understanding driver behavior is the basis for the development of many advanced driver assistance systems, and experimental studies are indispensable tools for constructing appropriate driver models. However, the high cost associated with testing is a serious obstacle in collecting large amounts of experimental data. This paper presents a methodology that can improve the reliability of results from experimental studies with a limited number of participants by creating a virtual population. Specifically, a methodology based on Bayesian inference has been developed, that generates synthetic cases that adhere to various real-world constraints and represent possible variations of the observed experimental data. The application of the framework is illustrated using data collected during a test-track experiment where truck drivers performed a right turn maneuver, with and without a cyclist crossing the intersection. The results show that, based on the speed profiles of the dataset and physical constraints, the methodology can produce synthetic speed profiles during braking that mimic the original curves but extend to other realistic braking patterns that were not directly observed. The models obtained from the proposed methodology have applications for the design of active safety systems and automated driving demonstrating thereby that the developed framework has great promise for the automotive industry

    More loosely bound hadron molecules at CDF?

    Get PDF
    In a recent paper we have proposed a method to estimate the prompt production cross section of X(3872) at the Tevatron assuming that this particle is a loosely bound molecule of a D and a D*bar meson. Under this hypothesis we find that it is impossible to explain the high prompt production cross section found by CDF at sigma(X(3872)) \sim 30-70 nb as our theoretical prediction is about 300 times smaller than the measured one. Following our work, Artoisenet and Braaten, have suggested that final state interactions in the DD*bar system might be so strong to push the result we obtained for the cross section up to the experimental value. Relying on their conclusions we show that the production of another very narrow loosely bound molecule, the X_s=D_s D_s*bar, could be similarly enhanced. X_s should then be detectable at CDF with a mass of 4080 MeV and a prompt production cross section of sigma(X_s) \sim 1-3 nb.Comment: Minor revisions made. To appear in Phys Lett
    corecore