2,299 research outputs found
Comment on `Note on X(3872) production at hadron colliders and its molecular structure'
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
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
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
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
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
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
The production of invisible pairs of lightest neutralinos accompanied by a
large-angle hard photon in the reaction
is studied at LEP2 energies. The most general gaugino/higgsino composition of
the within the Minimal Supersymmetric Standard Model is assumed. The
spectrum of the observed photon is derived within the framework of the
-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 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
We present high-quality optical data and density functional perturbation
theory calculations for the vibrational spectrum of solid picene
(CH) 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 () is much lower
than the effective value () 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
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?
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
- …