10,067 research outputs found
Coulomb corrections to inclusive cross sections at the future Electron - Ion Collider
The experimental results of the future electron -- ion () collider are
expected to constrain the dynamics of the strong interactions at small values
of the Bjorken -- variable and large nuclei. Recently it has been suggested
that Coulomb corrections can be important in inclusive and diffractive
interactions. In this paper we present a detailed investigation of the impact
of the Coulomb corrections to some of the observables that will be measured in
the future collider. In particular, we estimate the magnitude of these
corrections for the charm and longitudinal cross sections in inclusive and
diffractive interactions. Our results demonstrate that the Coulomb corrections
for these observables are negligible, which implies that they can be used to
probe the QCD dynamics.Comment: 9 pages, 6 figures. Improved version to be published in Physical
Review
Evidence of Nodal Line in the Superconducting Gap Symmetry of Noncentrosymmetric ThCoC
The newly discovered noncentrosymmetric superconductor ThCoC exhibits
numerous unconventional behavior in the field dependent heat capacity data.
Here we present the first measurement of the gap symmetry of ThCoC by
muon spin rotation/relaxation SR) measurements. Temperature dependence of
the magnetic penetration depth measured using the transverse field SR
measurement reveal the evidence of nodal pairing symmetry. To understand these
findings, we carry out the calculations of superconducting pairing eigenvalue
and eigenfunction symmetry due to the spin-fluctuation mechanism, by directly
implemented the {\it ab-initio} band structures. We find that the system
possesses a single Fermi surface with considerable three-dimensionality, and
hence a strong nesting along the -direction. Such a nesting promotes a
superconducting pairing with a -like symmetry with a prominent nodal
line on the plane. The result agrees well with the experimental
data.Comment: 3 pages, 5 figure
Exclusive vector meson production in electron-ion collisions
We calculate the nuclear cross section for coherent and incoherent vector
meson production within the QCD color dipole picture, including saturation
effects. Theoretical estimates for scattering on both light and heavy nuclei
are given over a wide range of energy.Comment: 11 pages, 6 figures, 1 tabl
Feature selection and novelty in computational aesthetics
[Abstract] An approach for exploring novelty in expression-based evolutionary art systems is presented. The framework is composed of a feature extractor, a classifier, an evolutionary engine and a supervisor. The evolutionary engine exploits shortcomings of the classifier, generating misclassified instances. These instances update the training set and the classifier is re-trained. This iterative process forces the evolutionary algorithm to explore new paths leading to the creation of novel imagery. The experiments presented and analyzed herein explore different feature selection methods and indicate the validity of the approach.Portugal. Fundação para a Ciência e a Tecnologia; PTDC/EIA–EIA/115667/2009Galicia.Consellería de Innovación, Industria e Comercio ; PGIDIT10TIC105008P
Imaging stress and magnetism at high pressures using a nanoscale quantum sensor
Pressure alters the physical, chemical and electronic properties of matter.
The development of the diamond anvil cell (DAC) enables tabletop experiments to
investigate a diverse landscape of high-pressure phenomena ranging from the
properties of planetary interiors to transitions between quantum mechanical
phases. In this work, we introduce and utilize a novel nanoscale sensing
platform, which integrates nitrogen-vacancy (NV) color centers directly into
the culet (tip) of diamond anvils. We demonstrate the versatility of this
platform by performing diffraction-limited imaging (~600 nm) of both stress
fields and magnetism, up to pressures ~30 GPa and for temperatures ranging from
25-340 K. For the former, we quantify all six (normal and shear) stress
components with accuracy GPa, offering unique new capabilities for
characterizing the strength and effective viscosity of solids and fluids under
pressure. For the latter, we demonstrate vector magnetic field imaging with
dipole accuracy emu, enabling us to measure the pressure-driven
phase transition in iron as well as the complex
pressure-temperature phase diagram of gadolinium. In addition to DC vector
magnetometry, we highlight a complementary NV-sensing modality using T1 noise
spectroscopy; crucially, this demonstrates our ability to characterize phase
transitions even in the absence of static magnetic signatures. By integrating
an atomic-scale sensor directly into DACs, our platform enables the in situ
imaging of elastic, electric and magnetic phenomena at high pressures.Comment: 18 + 50 pages, 4 + 19 figure
Efeito de sistemas de produção com integração lavoura-pecuária, no rendimento de grãos e algumas características agronômicas de milho, sob plantio direto.
Avaliacao de acessos do genero Stylosanthes para a producao de feno.
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