pinecone/core-2020-05-10-deduplication huggingface dataset:
Local oxidation of silicon surfaces by dynamic force microscopy : nanofabrication and water bridge formation

Local oxidation of siliconsurfaces by atomic force microscopy is a very promising lithographic approach at nanometer scale. Here, we study the reproducibility, voltage dependence, and kinetics when the oxidation is performed by dynamic force microscopy modes. It is demonstrated that during the oxidation, tip and sample are separated by a gap of a few nanometers. The existence of a gap increases considerably the effective tip lifetime for performing lithography. A threshold voltage between the tip and the sample must be applied in order to begin the oxidation. The existence of a threshold voltage is attributed to the formation of a water bridge between tip and sample. It is also found that the oxidation kinetics is independent of the force microscopy mode used (contact or noncontact)
Combined Measurement and QCD Analysis of the Inclusive ep Scattering
  Cross Sections at HERA

A combination is presented of the inclusive deep inelastic cross sections
measured by the H1 and ZEUS Collaborations in neutral and charged current
unpolarised ep scattering at HERA during the period 1994-2000. The data span
six orders of magnitude in negative four-momentum-transfer squared, Q^2, and in
Bjorken x. The combination method used takes the correlations of systematic
uncertainties into account, resulting in an improved accuracy. The combined
data are the sole input in a NLO QCD analysis which determines a new set of
parton distributions, HERAPDF1.0, with small experimental uncertainties. This
set includes an estimate of the model and parametrisation uncertainties of the
fit result.Comment: 61 pages, 21 figures, revised version accepted by JHE
Sigma terms and strangeness content of the nucleon with $N_f=2+1+1$
  twisted mass fermions

We study the nucleon matrix elements of the quark scalar-density operator
using maximally twisted mass fermions with dynamical light ($u$,$d$), strange
and charm degrees of freedom. We demonstrate that in this setup the nucleon
matrix elements of the light and strange quark densities can be obtained with
good statistical accuracy, while for the charm quark counterpart only a bound
can be provided. The present calculation which is performed at only one value
of the lattice spacing and pion mass serves as a benchmark for a future more
systematic computation of the scalar quark content of the nucleon
Alpha Cygnids - a possible July minor meteor shower

We present a comprehensive study of a possible $\alpha$-Cygnid meteor shower.
Based on visual and telescopic observations made by Polish observers we
estimate basic parameters of the stream. Activity of $\alpha$-Cygnids lasts
from around June 30 to July 31 with clear maximum near July 18 (solar longitude
$\lambda_\odot=116.5^\circ$). Maximal Zenithal Hourly Rates (ZHRs) are equal to
$3.6\pm1.2$. The structure of the radiant analyzed by {\sc radiant} software is
most compact for geocentric velocity of the events equal to 41 km/s, and for
the drift of the radiant (in units $^\circ$/day) equal to $\Delta\alpha=+0.6$
$\Delta\delta=+0.2$. Center of the radiant for the moment of maximum is
$\alpha=302.5^\circ$ $\delta=+46.3^\circ$.We derive population index $r$ equal
to $2.55\pm0.14$ from magnitude distribution of 738 possible members of the
stream. Comparing the velocity distributions of 754 possible $\alpha$-Cygnids
and 4339 sporadic events by $\chi^2$ and Kolmogorov-Smirnov tests we conclude
that both distributions are different with probability very close to 1.0.
Telescopic observations strictly confirm the results obtained from visual
observations. The smallest values of $\chi^2$ parameter we obtained for the
geocentric velocity equal to 40 km/s and for the drift of the radiant (in units
$^\circ$/day) equal to $\Delta\alpha=+0.6$ $\Delta\delta=+0.2$. The center of
the radiant for moment of maximum is $\alpha=304.9^\circ$ $\delta=+46.2^\circ$.
  In spite of making many photographic exposures we still have no photographic
or video confirmation of the existence of this stream.Comment: accepted for publication in Astronomy and Astrophysics, Supplement
  Series, 8 pages with 4 figure
Dispersion relations and soft pion theorems for K -> pi pi

We propose a new method to obtain the K -> pi pi amplitude from K -> pi which
allows one to fully account for the effects of final state interactions. The
method is based on a set of dispersion relations for the K -> pi pi amplitude
in which the weak Hamiltonian carries momentum. The soft pion theorem, which
relates this amplitude to the K -> pi amplitude, can be used to determine one
of the two subtraction constants - the second constant is at present known only
to leading order in chiral perturbation theory. We solve the dispersion
relations numerically and express the result in terms of the unknown higher
order corrections to this subtraction constant.Comment: Latex, 10 pages, 1 figure. Typo in eqs. (13,14) corrected, some
  rephrasing in the introductio
CLASH-VLT: The mass, velocity-anisotropy, and pseudo-phase-space density
  profiles of the z=0.44 galaxy cluster MACS 1206.2-0847

We use an unprecedented data-set of about 600 redshifts for cluster members,
obtained as part of a VLT/VIMOS large programme, to constrain the mass profile
of the z=0.44 cluster MACS J1206.2-0847 over the radial range 0-5 Mpc (0-2.5
virial radii) using the MAMPOSSt and Caustic methods. We then add external
constraints from our previous gravitational lensing analysis. We invert the
Jeans equation to obtain the velocity-anisotropy profiles of cluster members.
With the mass-density and velocity-anisotropy profiles we then obtain the first
determination of a cluster pseudo-phase-space density profile. The kinematics
and lensing determinations of the cluster mass profile are in excellent
agreement. This is very well fitted by a NFW model with mass M200=(1.4 +- 0.2)
10^15 Msun and concentration c200=6 +- 1, only slightly higher than theoretical
expectations. Other mass profile models also provide acceptable fits to our
data, of (slightly) lower (Burkert, Hernquist, and Softened Isothermal Sphere)
or comparable (Einasto) quality than NFW. The velocity anisotropy profiles of
the passive and star-forming cluster members are similar, close to isotropic
near the center and increasingly radial outside. Passive cluster members follow
extremely well the theoretical expectations for the pseudo-phase-space density
profile and the relation between the slope of the mass-density profile and the
velocity anisotropy. Star-forming cluster members show marginal deviations from
theoretical expectations. This is the most accurate determination of a cluster
mass profile out to a radius of 5 Mpc, and the only determination of the
velocity-anisotropy and pseudo-phase-space density profiles of both passive and
star-forming galaxies for an individual cluster [abridged]Comment: A&A in press; 22 pages, 19 figure
The rapidity dependence of the average transverse momentum in p+Pb
  collisions at the LHC: the Color Glass Condensate versus hydrodynamics

We show that in proton-lead (p+Pb) collisions at the LHC, the Color Glass
Condensate (CGC) and hydrodynamics lead to qualitatively different behavior of
the average transverse momentum, <p_T>, with the particles rapidity. In
hydrodynamics, the <p_T> decreases as one goes from zero rapidity, y=0, to the
proton fragmentation region since the number of particles decreases. In
contrast, in the CGC the saturation momentum increases as one goes from y=0 to
the proton fragmentation region, and so the <p_T> increases. At the LHC, the
difference between the two models may be large enough to be tested
experimentally.Comment: 4 pages, 2 figure
Three-gluon running coupling from lattice QCD at $N_f=2+1+1$: a
  consistency check of the OPE approach

We present a lattice calculation of the renormalized running coupling
constant in symmetric (MOM) and asymmetric ($\widetilde{\rm MOM}$) momentum
substraction schemes including $u$, $d$, $s$ and $c$ quarks in the sea. An
Operator Product Expansion dominated by the dimension-two $\langle A^2\rangle$
condensate is used to fit the running of the coupling. We argue that the
agreement in the predicted $\langle A^2\rangle$ condensate for both schemes is
a strong support for the validity of the OPE approach and the effect of this
non-gauge invariant condensate over the running of the strong coupling.Comment: Revised version (8 pages, 5 figures
Derivation of the action and symmetries of the q-deformed AdS_5 x S^5
  superstring

We recently proposed an integrable q-deformation of the AdS_5 x S^5
superstring action. Here we give details on the hamiltonian origin and
construction of this deformation. The procedure is a generalization of the one
previously developed for deforming principal chiral and symmetric space
sigma-models. We also show that the original psu(2,2|4) symmetry is replaced in
the deformed theory by a classical analog of the quantum group U_q(psu(2,2|4))
with q real. The relation between q and the deformation parameter entering the
action is given. The framework used to derive the deformation also enables to
prove that at the hamiltonian level, the "maximal deformation" limit
corresponds to an undeformed semi-symmetric space sigma-model with bosonic part
dS_5 x H^5. Finally, we discuss the various freedoms in the construction.Comment: 42 pages, 1 figure; v2: minor typos corrected and references adde
Quasi-quantization: classical statistical theories with an epistemic
  restriction

A significant part of quantum theory can be obtained from a single innovation
relative to classical theories, namely, that there is a fundamental restriction
on the sorts of statistical distributions over physical states that can be
prepared. This is termed an "epistemic restriction" because it implies a
fundamental limit on the amount of knowledge that any observer can have about
the physical state of a classical system. This article provides an overview of
epistricted theories, that is, theories that start from a classical statistical
theory and apply an epistemic restriction. We consider both continuous and
discrete degrees of freedom, and show that a particular epistemic restriction
called classical complementarity provides the beginning of a unification of all
known epistricted theories. This restriction appeals to the symplectic
structure of the underlying classical theory and consequently can be applied to
an arbitrary classical degree of freedom. As such, it can be considered as a
kind of quasi-quantization scheme; "quasi" because it generally only yields a
theory describing a subset of the preparations, transformations and
measurements allowed in the full quantum theory for that degree of freedom, and
because in some cases, such as for binary variables, it yields a theory that is
a distortion of such a subset. Finally, we propose to classify quantum
phenomena as weakly or strongly nonclassical by whether or not they can arise
in an epistricted theory.Comment: 35 pages, 15 figures, comments welcom
Nuclear Parton Distributions - a DGLAP Analysis

Nuclear parton distributions $f_A(x,Q^2)$ are studied within a framework of
the DGLAP evolution. Measurements of $F_2^A/F_2^D$ in deep inelastic $lA$
collisions, and Drell--Yan dilepton cross sections measured in $pA$ collisions
are used as constraints. Also conservation of momentum and baryon number is
required. It is shown that the calculated $Q^2$ evolution of $F_2^{\rm
Sn}/F_2^{\rm C}$ agrees very well with the recent NMC data, and that the ratios
$R_f^A=f_A/f$ are only moderately sensitive to the choice of a specific modern
set of free parton distributions. For general use, we offer a numerical
parametrization of $R_f^A(x,Q^2)$ for all parton flavours $f$ in $A>2$, and at
$10^{-6}\le x \le 1$ and $2.25 {\rm GeV}^2\le Q^2\le 10^4 {\rm GeV}^2$.Comment: Talk in Quark Matter '99, 5 pages, includes 3 eps-figure
New Inhomogeneous Einstein Metrics on Sphere Bundles Over
  Einstein-Kahler Manifolds

We construct new complete, compact, inhomogeneous Einstein metrics on S^{m+2}
sphere bundles over 2n-dimensional Einstein-Kahler spaces K_{2n}, for all n \ge
1 and all m \ge 1. We also obtain complete, compact, inhomogeneous Einstein
metrics on warped products of S^m with S^2 bundles over K_{2n}, for m>1.
Additionally, we construct new complete, non-compact Ricci-flat metrics with
topologies S^m times R^2 bundles over K_{2n} that generalise the
higher-dimensional Taub-BOLT metrics, and with topologies S^m \times R^{2n+2}
that generalise the higher-dimensional Taub-NUT metrics, again for m>1.Comment: Latex, 14 pages. Errors and typos corrected, and related references
  adde
Cohomogeneity-one Einstein-Weyl structures: a local approach

We analyse in a systematic way the (non-)compact n-dimensional Einstein Weyl spaces equipped with a cohomogeneity-one metric. With no compactness hypothesis, we prove that, as soon as the (n-1)-dimensional basis space is an homogeneous reductive Riemannian space with an unimodular group of left-acting isometries G 1)a non-exact Einstein-Weyl stucture may exist only if the (n-1)-dimensional basis homogeneous space G/H contains a non trivial subgroup H' that commutes with the isotropy subgroup H, 2) the extra isometry due to this Killing vector corresponds to the right-action of one of the generators of the algebra of the subgroup H'. We also prove that the subclass with a one-dimensional subgroup H' corresponds to n-dimensional Riemannian locally conformally Kähler metrics, the (n-2)-dimensional basis being an arbitrary compact symmetric Kähler coset space
On gravitational interaction of fermions

We discuss some aspects of the gravitational interaction of the relativistic quantum particles with spin 1/2. The exact Foldy-Wouthuysen transformation is constructed for the Dirac particle coupled to the static spacetime metric. The quasi-relativistic limit of the theory is then analyzed. Using the analogous method, we obtain the exact Cini-Touschek transformation and discuss the ultra-relativistic limit of the fermion theory. We show that the Foldy-Wouthuysen transformation is not uniquely defined, and the corresponding ambiguity is deeply rooted in the relativistic quantum theory
A Spitzer high-resolution mid-infrared spectral atlas of starburst galaxies

We present an atlas of Spitzer/IRS high-resolution (R ~ 600) 10-37 µm spectra for 24 well known starburst galaxies. The spectra are dominated by fine-structure lines, molecular hydrogen lines, and emission bands of polycyclic aromatic hydrocarbons (PAHs). Six out of the eight objects with a known active galactic nucleus (AGN) component show emission of the high excitation [Ne V] line. This line is also seen in one other object (NGC 4194) with, a priori, no known AGN component. In addition to strong PAH emission features in this wavelength range (11.3, 12.7, 16.4 µm), the spectra reveal other weak hydrocarbon features at 10.6, 13.5, 14.2 µm, and a previously unreported emission feature at 10.75 µm. An unidentified absorption feature at 13.7 µm is detected in many of the starbursts. We use the fine-structure lines to derive the abundance of neon and sulfur for 14 objects where the H I 7-6 line is detected. We further use the molecular hydrogen lines to sample the properties of the warm molecular gas. Several basic diagrams characterizing the properties of the sample are also shown. We have combined the spectra of all the pure starburst objects to create a high signal-to-noise ratio template, which is available to the community
Generation and characterization of T40/A5754 interfaces with lasersPatrice

Laser-induced reactive wetting and brazing of T40 titanium with A5754 aluminum alloy with 1.5 mm thickness was carried out in lap-joint conﬁguration, with or without the use of Al5Si ﬁller wire. A 2.4 mm diameter laser spot was positioned on the aluminum side to provoke spreading and wetting of the lower titanium sheet, with relatively low scanning speeds (0.1–0.6 m/min). Process conditions did not play a very signiﬁcant role on mechanical strengths, which were shown to reach 250–300 N/mm on a large range of laser power and scanning speeds. In all cases considered, the fracture during tensile testing occurred next to the TiAl3 interface, but in the aluminum fusion zone. The interfacial resistance was then evaluated with the LASAT bond strength tester, based upon the generation and propagation of laser-induced shock waves. A 0.68 GPa uniaxial bond strength was estimated for the T40/A5754 interface under dynamic loading conditions
Experimental and numerical analysis of the martensitic transformation in AISI 304 steel sheets subjected to perforation by conical and hemispherical projectiles

In this work, an experimental and numerical analysis of the martensitic transformation in AISI 304 steel sheets subjected to perforation by conical and hemispherical projectiles is conducted. Experiments are performed using a pneumatic gas gun for with the impact velocities in the range of 35 m/s < V-0 < 200 m/s. Two target thicknesses are examined, t(1) = 0.5 mm and t(2) = 1.0 mm. The experimental setup enabled the determination of the impact velocity, the residual velocity and the failure mode of the steel sheets. The effect of the projectile nose shape on the target's capacity for energy absorption is evaluated. Moreover, martensite is detected in all the impacted samples, and the role played by the projectile nose shape on the transformation is highlighted. A three-dimensional model is developed in ABAQUS/Explicit to simulate the perforation tests. The material is defined via the constitutive model developed by Zaera et al. (2012) to describe the strain-induced martensitic transformation occurring in metastable austenitic steels at high strain rates. The finite element results are compared with the experimental evidence, and satisfactory matching is observed over the entire range of impact velocities tested and for both projectile configurations and target thicknesses considered. The numerical model succeeds in describing the perforation mechanisms associated with each projectile-target configuration analyzed. The roles played by impact velocity, target thickness and projectile nose shape on the martensitic transformation are properly captured.The researchers of the University Carlos III of Madrid are in
debted to the Comunidad Autónoma de Madrid (Project CCG10
UC3M/DPI 5596) and to the Ministerio de Ciencia e Innovación
de España (DPI2011 24068) for the financial support received
which allowed conducting part of this work
Long distance manipulation of a levitated nanoparticle in high vacuum

Accurate delivery of small targets in high vacuum is a pivotal task in many
branches of science and technology. Beyond the different strategies developed
for atoms, proteins, macroscopic clusters and pellets, the manipulation of
neutral particles over macroscopic distances still poses a formidable
challenge. Here we report a novel approach based on a mobile optical trap
operated under feedback control that enables long range 3D manipulation of a
silica nanoparticle in high vacuum. We apply this technique to load a single
nanoparticle into a high-finesse optical cavity through a load-lock vacuum
system. We foresee our scheme to benefit the field of optomechanics with
levitating nano-objects as well as ultrasensitive detection and monitoring.Comment: 12 pages 5 figure
High resolution imaging of NGC 2346 with GSAOI/GeMS: disentangling the
  planetary nebula molecular structure to understand its origin and evolution

We present high spatial resolution ($\approx$ 60--90 milliarcseconds) images
of the molecular hydrogen emission in the Planetary Nebula (PN) NGC 2346. The
data were acquired during the System Verification of the Gemini Multi-Conjugate
Adaptive Optics System + Gemini South Adaptive Optics Imager. At the distance
of NGC 2346, 700 pc, the physical resolution corresponds to $\approx$ 56 AU,
which is slightly higher than that an [N II] image of NGC 2346 obtained with
HST/WFPC2. With this unprecedented resolution we were able to study in detail
the structure of the H$_2$ gas within the nebula for the first time. We found
it to be composed of knots and filaments, which at lower resolution had
appeared to be a uniform torus of material. We explain how the formation of the
clumps and filaments in this PN is consistent with a mechanism in which a
central hot bubble of nebular gas surrounding the central star has been
depressurized, and the thermal pressure of the photoionized region drives the
fragmentation of the swept-up shell.Comment: accepted in ApJ (17 pages, 7 figures, 1 Table
A simple non-chaotic map generating subdiffusive, diffusive and
  superdiffusive dynamics

Analytically tractable dynamical systems exhibiting a whole range of normal
and anomalous deterministic diffusion are rare. Here we introduce a simple
non-chaotic model in terms of an interval exchange transformation suitably
lifted onto the whole real line which preserves distances except at a countable
set of points. This property, which leads to vanishing Lyapunov exponents, is
designed to mimic diffusion in non-chaotic polygonal billiards that give rise
to normal and anomalous diffusion in a fully deterministic setting. As these
billiards are typically too complicated to be analyzed from first principles,
simplified models are needed to identify the minimal ingredients generating the
different transport regimes. For our model, which we call the slicer map, we
calculate all its moments in position analytically under variation of a single
control parameter. We show that the slicer map exhibits a transition from
subdiffusion over normal diffusion to superdiffusion under parameter variation.
Our results may help to understand the delicate parameter dependence of the
type of diffusion generated by polygonal billiards. We argue that in different
parameter regions the transport properties of our simple model match to
different classes of known stochastic processes. This may shed light on
difficulties to match diffusion in polygonal billiards to a single anomalous
stochastic process.Comment: 15 pages, 3 figure
Dynamics of Perturbations in Double Field Theory & Non-Relativistic
  String Theory

Double Field Theory provides a geometric framework capable of describing
string theory backgrounds that cannot be understood purely in terms of
Riemannian geometry -- not only globally (`non-geometry'), but even locally
(`non-Riemannian'). In this work, we show that the non-relativistic closed
string theory of Gomis and Ooguri [1] arises precisely as such a non-Riemannian
string background, and that the Gomis-Ooguri sigma model is equivalent to the
Double Field Theory sigma model of [2] on this background. We further show that
the target-space formulation of Double Field Theory on this non-Riemannian
background correctly reproduces the appropriate sector of the Gomis-Ooguri
string spectrum. To do this, we develop a general semi-covariant formalism
describing perturbations in Double Field Theory. We derive compact expressions
for the linearized equations of motion around a generic on-shell background,
and construct the corresponding fluctuation Lagrangian in terms of novel
completely covariant second order differential operators. We also present a new
non-Riemannian solution featuring Schr\"odinger conformal symmetry.Comment: 1+42 pages, Refs. added, minor changes. To appear in JHE