pinecone/core-2020-05-10-deduplication huggingface dataset:
Correlations, spin dynamics, defects: the highly-frustrated Kagom\'{e}
  bilayer

The SrCr$\_{9p}$Ga$\_{12-9p}$O$\_{19}$ and
Ba$\_{2}$Sn$\_{2}$ZnGa$\_{10-7p}$Cr$\_{7p}$O$\_{22}$ compounds are two
highly-frustrated magnets possessing a quasi-two-dimensional Kagom\'{e} bilayer
of spin 3/2 chromium ions with antiferromagnetic interactions. Their magnetic
susceptibility was measured by local Nuclear Magnetic Resonance and non-local
(SQUID) techniques, and their low-temperature spin dynamics by Muon Spin
Resonance. Consistent with the theoretical picture drawn for geometrically
frustrated systems, the Kagom\'{e} bilayer is shown here to exhibit: (i) short
range spin-spin correlations down to a temperature much lower than the
Curie-Weiss temperature, no conventional long-range transition occurring; (ii)
a Curie contribution to the susceptibility from paramagnetic defects generated
by spin vacancies; (iii) low-temperature spin fluctuations, at least down to 30
mK, which are a trademark of a dynamical ground state. These properties point
to a spin-liquid ground state, possibly built on Resonating Valence Bonds with
unconfined spinons as the magnetic excitations.Comment: 21 pages, 24 figure
The Einstein 3-form G_a and its equivalent 1-form L_a in Riemann-Cartan
  space

The definition of the Einstein 3-form G_a is motivated by means of the
contracted 2nd Bianchi identity. This definition involves at first the complete
curvature 2-form. The 1-form L_a is defined via G_a = L^b \wedge #(o_b \wedge
o_a). Here # denotes the Hodge-star, o_a the coframe, and \wedge the exterior
product. The L_a is equivalent to the Einstein 3-form and represents a certain
contraction of the curvature 2-form. A variational formula of Salgado on
quadratic invariants of the L_a 1-form is discussed, generalized, and put into
proper perspective.Comment: LaTeX, 13 Pages. To appear in Gen. Rel. Gra
Hawking radiation from dilaton gravity in 1 + 1 dimensions: a
  pedagogical review

Hawking radiation in d=4 is regarded as a well understood quantum theoretical
feature of Black Holes or of other geometric backgrounds with an event horizon.
On the other hand, the dilaton theory emerging after spherical reduction and
generalized dilaton theories only during the last years became the subject of
numerous studies which unveiled a surprisingly difficult situation. Recently we
have found some solution to the problem of Hawking flux in spherically reduced
gravity which has the merit of using a minimal input. It leads to exact
cancellation of negative contributions to this radiative flux, encountered in
other approaches at infinity, so that our result asymptotically coincides with
the one of minimally coupled scalars. The use of an integrated action is
avoided - although we have been able to present also that quantity in a closed
expression. This short review also summarizes and critically discusses recent
activities in this field, including the problem of ``conformal frames'' for the
background and questions which seem to be open in our own approach as well as
in others.Comment: latex2e, to appear in Annalen der Physi
Exotic symmetry and monodromy equivalence in Schrodinger sigma models

We consider the classical integrable structure of two-dimensional non-linear
sigma models with target space three-dimensional Schrodinger spacetimes. There
are the two descriptions to describe the classical dynamics: 1) the left
description based on SL(2,R)_L and 2) the right description based on U(1)_R. We
have shown the sl(2,R)_L Yangian and q-deformed Poincare algebras associated
with them. We proceed to argue an infinite-dimensional extension of the
q-deformed Poincare algebra. The corresponding charges are constructed by using
a non-local map from the flat conserved currents related to the Yangian. The
exotic tower structure of the charges is revealed by directly computing the
classical Poisson brackets. Then the monodromy matrices in both descriptions
are shown to be gauge-equivalent via the relation between the spectral
parameters. We also give a simple Riemann sphere interpretation of this
equivalence.Comment: 27 pages, 3 figures, LaTeX, Further clarifications adde
Magnetically Controlled Accretion on the Classical T Tauri Stars GQ Lupi
  and TW Hydrae

We present high spectral resolution ($R\approx108,000$) Stokes $V$
polarimetry of the Classical T Tauri stars (CTTSs) GQ Lup and TW Hya obtained
with the polarimetric upgrade to the HARPS spectrometer on the ESO 3.6 m
telescope. We present data on both photospheric lines and emission lines,
concentrating our discussion on the polarization properties of the \ion{He}{1}
emission lines at 5876 \AA\ and 6678 \AA. The \ion{He}{1} lines in these CTTSs
contain both narrow emission cores, believed to come from near the accretion
shock region on these stars, and broad emission components which may come from
either a wind or the large scale magnetospheric accretion flow. We detect
strong polarization in the narrow component of the two \ion{He}{1} emission
lines in both stars. We observe a maximum implied field strength of $6.05 \pm
0.24$ kG in the 5876 \AA\ line of GQ Lup, making it the star with the highest
field strength measured in this line for a CTTS. We find field strengths in the
two \ion{He}{1} lines that are consistent with each other, in contrast to what
has been reported in the literature on at least one star. We do not detect any
polarization in the broad component of the \ion{He}{1} lines on these stars,
strengthening the conclusion that they form over a substantially different
volume relative the formation region of the narrow component of the \ion{He}{1}
lines.Comment: 17 pages, 4 figures, Accepted to The Astrophysical Journa
An SO(10) GUT Model With Lopsided Mass Matrix and Neutrino Mixing Angle
  theta_13

An alternative supersymmetric SO(10) grand unification model with lopsided
fermion mass matrices is introduced. It generates a large solar-neutrino-mixing
angle through the neutrinos' Dirac mass matrix constrained by the SO(10) group
structure, avoiding the fine-tuning required in the Majorana mass matrix of
right-handed neutrinos. The model fits well the known data on masses and
mixings of quarks and leptons, and predicts a sizable lepton mixing
$\sin^22\theta_{13}\simeq 0.074$, which is significantly larger than that of
the original lopsided model.Comment: 9 page
CP violation and limits on New Physics including recent $B_s$
  measurements

We analyse present constraints on the SM parameter space and derive, in a
model independent way, various bounds on New Physics contributions to
$B_d^0$--$\bar B_d^0$ and $B_s^0$--$\bar B_s^0$ mixings. Our analyses include
information on a large set of asymmetries, leading to the measurement of the
CKM phases $\gamma$ and $\bar\beta$, as well as recent data from D0 and CDF
related to the $B_s^0$--$\bar B_s^0$ system such as the measurement of $\Delta
M_{B_s}$, $A_{SL}$ and $\Delta\Gamma_{s}^{CP}$. We examine in detail several
observables such as the asymmetries $A_{sl}^d$, $A_{SL}$, the width differences
$\Delta\Gamma_{d}$ and $\Delta\Gamma_{s}^{CP}$ and discuss the r\^ole they play
in establishing the limits on New Physics. The present data clearly favour the
SM, with the New Physics favoured region placed around the SM solution. A New
Physics solution significantly different from the SM is still allowed, albeit
quite disfavoured (2.6% probability). We analyse the presently available
indirect knowledge on the phase $\bar\chi$ entering in $B_s^0$--$\bar B_s^0$
mixing and study the impact of a future measurement of $\bar\chi$ to be
achieved at LHC, through the measurement of the time-dependent CP asymmetry in
$B_s\to J/\Psi \Phi$ decays.Comment: 29 pages, 31 figures; updated analyses and reference
Dilepton Signatures of Family Non-Universal U(1)'

The supersymmetric models extending the minimal supersymmetric standard model
(MSSM) by an additional Abelian gauge factor U(1)' in order to solve the mu
problem do generically suffer from anomalies disrupting the gauge coupling
unification found in the MSSM. The anomalies are absent if the minimal matter
content necessitated by the mu problem is augmented with exotic matter species
having appropriate quantum numbers. Recently, it has been shown that anomaly
cancellation can also be accomplished by introducing family non-universal U(1)'
charges and non-holomoprhic soft-breaking terms. We discuss collider signatures
of anomaly-free family non-universal U(1)' model by analyzing dilepton
production in future colliders. We find that, both at LHC and NLC, one can
establish existence/absence of such a Z' boson by simply comparing the number
of dilepton production events for electron, muon and tau lepton. The signal is
free of the SM background.Comment: 12 pages, 4 figure
NIR and optical observations of the failed outbursts of black hole
  binary XTE J1550-564

A number of low mass X-ray binaries (LMXBs) undergo "failed outbursts" in
which, instead of evolving through the canonical states, they remain in a hard
state throughout the outburst. While the sources of X-ray and radio emission in
the hard state are relatively well understood, the origin of the near infrared
(NIR) and optical emission is more complex though it likely stems from an
amalgam of different emission processes, occurring as it does, at the
intersecting wavelengths of those processes. We aim to identify the NIR/optical
emission region(s) during a number of failed outbursts of one such low mass
X-ray binary and black hole candidate, XTE J1550-564, in order to confirm or
refute their classification as hard-state, failed outbursts. We present unique
NIR/optical images and spectra, obtained with the ESO-New Technology Telescope,
during the failed outbursts of 2001 and 2000. We compare the NIR/optical
photometric, timing, and spectral properties with those expected for the
different emission mechanisms in the various LMXB states. The NIR/optical data
are consistent with having come from reprocessing of X-rays in the accretion
disk, with no evidence of direct thermal emission from the disk itself.
However, the observed variability in high-cadence NIR light curves suggest that
the radio jet extends and contributes to the NIR wavelengths. We find that
these failed outbursts did not transition to an intermediate state but remained
in a true, hard state where there was no sign of jet quenching or deviation
from the observed hard state correlations.Comment: Accepted to Astronomy & Astrophysics (8 pages
Mobility of core water in Bacillus subtilis spores by $^2$H NMR

Bacterial spores in a metabolically dormant state can survive long periods
without nutrients under extreme environmental conditions. The molecular basis
of spore dormancy is not well understood, but the distribution and physical
state of water within the spore is thought to play an important role. Two
scenarios have been proposed for the spore's core region, containing the DNA
and most enzymes. In the gel scenario, the core is a structured macromolecular
framework permeated by mobile water. In the glass scenario, the entire core,
including the water, is an amorphous solid and the quenched molecular diffusion
accounts for the spore's dormancy and thermal stability. Here, we use $^2$H
magnetic relaxation dispersion to selectively monitor water mobility in the
core of Bacillus subtilis spores in the presence and absence of core Mn$^{2+}$
ions. We also report and analyze the solid-state $^2$H NMR spectrum from these
spores. Our NMR data clearly support the gel scenario with highly mobile core
water (~ 25 ps average rotational correlation time). Furthermore, we find that
the large depot of manganese in the core is nearly anhydrous, with merely 1.7 %
on average of the maximum sixfold water coordination.Comment: 11 pages, 5 figure
Electronic and atomic structure of complex defects in highly n-type
  doped ZnO films

Point defects in Ga- and Al-doped ZnO thin films are studied by means of
first principles electronic structure calculations. Candidate defects are
identified to explain recently observed differences in electrical and
spectroscopical behavior of both systems. Substitutional doping in Ga-ZnO
explain the metallic behavior of the electrical properties. Complexes of
interstitial oxygen with substitutional Ga can behave as acceptor and cause
partial compensation, as well as gap states below the conduction band minimum
as observed in photoemission experiments. Zn vacancies can also act as
compensating acceptors. On the other hand, the semiconducting behavior of
Al-ZnO and the small variation in the optical gap compared with pure ZnO, can
be explained by almost complete compensation between acceptor Zn vacancies and
substitutional Al donors. Interstitial Al can also be donor levels and can be
the origin of the small band observed in photoemission experiments below the
Fermi level. Combinations of substitutional Al with interstitial oxygen can act
simultaneously as compensating acceptor and generator o the mentioned
photoemission band. The theoretical calculations have been done using density
functional theory (DFT) within the generalized gradient approximation with
on-site Coulomb interaction. In selected cases, DFT calculations with
semilocal-exact exchange hybrid functionals have been performed. Results are
compared with photoelectron spectra for Ga-ZnO and Al-ZnO at the corresponding
doping levels.Comment: 10 pages, 10 figures, UTF-8 encoding. To be publishe
Status of double beta decay experiments using isotopes other than Xe-136

Neutrinoless double beta decay is a lepton-number violating process predicted
by many extensions of the standard model. It is actively searched for in
several candidate isotopes within many experimental projects. The status of the
experimental initiatives which are looking for the neutrinoless double beta
decay in isotopes other than Xe-136 is reviewed, with special emphasis given to
the projects that passed the R&D phase. The results recently released by the
experiment GERDA are also summarized and discussed. The GERDA data give no
positive indication of neutrinoless double beta decay of Ge-76 and disfavor in
a model-independent way the long-standing observation claim on the same
isotope. The lower limit reported by GERDA for the half-life of neutrinoless
double beta decay of Ge-76 is T1/2 > 2.1e25 yr (90% C.L.), or T1/2 > 3.0e25 yr,
when combined with the results of other Ge-76 predecessor experiments.Comment: Manuscript prepared for the proceedings of the TAUP2013 Conference
  (Asilomar, US), invited plenary talk. Submitted to Physics of the Dark
  Univers
An "outside-in" outburst of Aql X-1

We present optical spectroscopy and optical and infrared photometry of the neutron star soft X-ray transient Aql X--1 during its X-ray outburst of August 1997. By modelling the X-ray, optical, and IR light curves, we find a 3 day delay between the IR and X-ray rise times, analogous to the UV-optical delay seen in dwarf novae outbursts and black hole X-ray transients. We interpret this delay as the signature of an ``outside-in'' outburst, in which a thermal instability in the outer disc propagates inward. This outburst is the first of this type definitively identified in a neutron star X-ray transient
Equilibrium sizes of jellium metal clusters in the stabilized spin-polarized jellium model

We have used the stabilized spin-polarized jellium model to calculate the equilibrium sizes of metal clusters. Our self-consistent calculations in the local spin-density approximation show that for an $N$-electron cluster, the equilibrium is achieved for a configuration in which the difference in the numbers of up-spin and down-spin electrons is zero or unity, depending on the total number of electrons. That is, a configuration in which the spins are maximally compensated. This maximum spin-compensation results in both the alternation in the average distance between the nearest neighbor ions and the odd-even alternations in the ionization energies of alkali metal clusters, in a good agreement with the molecular dynamics findings and the experiment. These suggest a realistic and more accurate method for calculating the properties of metal clusters in the context of jellium model than previous jellium model methods
Dust Spectral Energy Distributions in the Era of Herschel and Planck: A Hierarchical Bayesian-Fitting Technique

We present a hierarchical Bayesian method for fitting infrared spectral energy distributions (SEDs) of dust emission to observed fluxes. Under the standard assumption of optically thin single temperature (T) sources, the dust SED as represented by a power-law-modified blackbody is subject to a strong degeneracy between T and the spectral index \(\beta\). The traditional non-hierarchical approaches, typically based on \(\chi^2\) minimization, are severely limited by this degeneracy, as it produces an artificial anti-correlation between T and \(\beta\) even with modest levels of observational noise. The hierarchical Bayesian method rigorously and self-consistently treats measurement uncertainties, including calibration and noise, resulting in more precise SED fits. As a result, the Bayesian fits do not produce any spurious anti-correlations between the SED parameters due to measurement uncertainty. We demonstrate that the Bayesian method is substantially more accurate than the \(\chi^2\) fit in recovering the SED parameters, as well as the correlations between them. As an illustration, we apply our method to Herschel and submillimeter ground-based observations of the star-forming Bok globule CB244. This source is a small, nearby molecular cloud containing a single low-mass protostar and a starless core. We find that T and \(\beta\) are weakly positively correlated—in contradiction with the \(\chi^2\) fits, which indicate a T-\(\beta\) anti-correlation from the same data set. Additionally, in comparison to the \(\chi^2\) fits the Bayesian SED parameter estimates exhibit a reduced range in values.Astronom
Altered brain morphometry in carpal tunnel syndrome is associated with median nerve pathology☆☆☆

Objective: Carpal tunnel syndrome (CTS) is a common median nerve entrapment neuropathy characterized by pain, paresthesias, diminished peripheral nerve conduction velocity (NCV) and maladaptive functional brain neuroplasticity. We evaluated structural reorganization in brain gray matter (GM) and white matter (WM) and whether such plasticity is linked to altered median nerve function in CTS. Methods: We performed NCV testing, T1-weighted structural MRI, and diffusion tensor imaging (DTI) in 28 CTS and 28 age-matched healthy controls (HC). Voxel-based morphometry (VBM) contrasted regional GM volume for CTS versus HC. Significant clusters were correlated with clinical metrics and served as seeds to define associated WM tracts using DTI data and probabilistic tractography. Within these WM tracts, fractional anisotropy (FA), axial (AD) and radial (RD) diffusivity were evaluated for group differences and correlations with clinical metrics. Results: For CTS subjects, GM volume was significantly reduced in contralesional S1 (hand-area), pulvinar and frontal pole. GM volume in contralesional S1 correlated with median NCV. NCV was also correlated with RD and was negatively correlated with FA within U-fiber cortico-cortical association tracts identified from the contralesional S1 VBM seed. Conclusions: Our study identified clear morphometric changes in the CTS brain. This central morphometric change is likely secondary to peripheral nerve pathology and altered somatosensory afference. Enhanced axonal coherence and myelination within cortico-cortical tracts connecting primary somatosensory and motor areas may accompany peripheral nerve deafferentation. As structural plasticity was correlated with NCV and not symptomatology, the former may be a better determinant of appropriate clinical intervention for CTS, including surgery
Finite depth effects on solitary waves in a floating ice sheet

A theoretical and numerical study of two-dimensional nonlinear flexural-gravity waves propagating at the surface of an ideal fluid of finite depth, covered by a thin ice sheet, is presented. The ice-sheet model is based on the special Cosserat theory of hyperelastic shells satisfying Kirchhoff׳s hypothesis, which yields a conservative and nonlinear expression for the bending force. From a Hamiltonian reformulation of the governing equations, two weakly nonlinear wave models are derived: a 5th-order Korteweg–de Vries equation in the long-wave regime and a cubic nonlinear Schrödinger equation in the modulational regime. Solitary wave solutions of these models and their stability are analysed. In particular, there is a critical depth below which the nonlinear Schrödinger equation is of focusing type and thus admits stable soliton solutions. These weakly nonlinear results are validated by comparison with direct numerical simulations of the full governing equations. It is observed numerically that small- to large-amplitude solitary waves of depression are stable. Overturning waves of depression are also found for low wave speeds and sufficiently large depth. However, solitary waves of elevation seem to be unstable in all cases
Halo effective field theory constrains the solar Beryllium-7 + proton ->
  Boron-8 + photon rate

We report an improved low-energy extrapolation of the cross section for the
process Beryllium-7+proton -> Boron-8+photon, which determines the Boron-8
neutrino flux from the Sun. Our extrapolant is derived from Halo Effective
Field Theory (EFT) at next-to-leading order. We apply Bayesian methods to
determine the EFT parameters and the low-energy S-factor, using measured cross
sections and scattering lengths as inputs. Asymptotic normalization
coefficients of Boron-8 are tightly constrained by existing radiative capture
data, and contributions to the cross section beyond external direct capture are
detected in the data at E < 0.5 MeV. Most importantly, the S-factor at zero
energy is constrained to be S(0)= 21.3 + - 0.7 eV b, which is an uncertainty
smaller by a factor of two than previously recommended. That recommendation was
based on the full range for S(0) obtained among a discrete set of models judged
to be reasonable. In contrast, Halo EFT subsumes all models into a controlled
low-energy approximant, where they are characterized by nine parameters at
next-to-leading order. These are fit to data, and marginalized over via Monte
Carlo integration to produce the improved prediction for S(E).Comment: 7 pages, 3 figures, 2 tables, and 1 supplemental materia
Influence of silica fume on the microstructure of cement pastes: New insights from H NMR relaxometry

H NMR has been used to characterise white Portland cement paste incorporating 10 wt.% of silica fume. Samples were measured sealed throughout the hydration without sample drying. Paste compositions and C-S-H characteristics are calculated based on H NMR signal intensities and relaxation analysis. The results are compared with a similar study of plain white cement paste. While the presence of silica fume has little influence on C-S-H densities, the chemical composition is impacted. After 28 days of sealed hydration, the Ca/(Si + Al) ratio of the C-S-H is 1.33 and the  H2O(Si + Al) ratio is 1.10 when 10% of silica fume is added to the white cement. A densification of the C-S-H with time is observed. There are no major changes in capillary, C-S-H gel and interlayer pore sizes for the paste containing silica fume compared to the plain white cement paste. However, the gel/interlayer water ratio increases in the silica fume blend