pinecone/core-2020-05-10-deduplication huggingface dataset:
SU(5) Tops with Multiple U(1)s in F-theory

We study F-theory compactifications with up to two Abelian gauge group
factors that are based on elliptically fibered Calabi-Yau 4-folds describable
as generic hypersurfaces. Special emphasis is put on elliptic fibrations based
on generic Bl^2 P^2[3]-fibrations. These exhibit a Mordell-Weil group of rank
two corresponding to two extra rational sections which give rise to two Abelian
gauge group factors. We show that an alternative description of the same
geometry as a complete intersection makes the existence of a holomorphic
zero-section manifest, on the basis of which we compute the U(1) generators and
a class of gauge fluxes. We analyse the fibre degenerations responsible for the
appearance of localised charged matter states, whose charges, interactions and
chiral index we compute geometrically. We implement an additional SU(5) gauge
group by constructing the four inequivalent toric tops giving rise to SU(5) x
U(1) x U(1) gauge symmetry and analyse the matter content. We demonstrate that
notorious non-flat points can be avoided in well-defined Calabi-Yau 4-folds.
These methods are applied to the remaining possible hypersurface fibrations
with one generic Abelian gauge factor. We analyse the local limit of our SU(5)
x U(1) x U(1) models and show that one of our models is not embeddable into E8
due to recombination of matter curves that cannot be described as a Higgsing of
E8. We argue that such recombination forms a general mechanism that opens up
new model building possibilities in F-theory.Comment: 72 pages, 12 figures; v2: references added, typos corrected, matches
  version published in Nucl. Phys.
Search for time-independent neutrino emission from astrophysical sources
  with 3 years of IceCube data

We present the results of a search for neutrino point sources using the
IceCube data collected between April 2008 and May 2011 with three partially
completed configurations of the detector: the 40-, 59- and 79-string
configurations. The live-time of this data set are 1,040 days. An unbinned
maximum likelihood ratio test was used to search for an excess of neutrinos
above the atmospheric background at any given direction in the sky. By adding
two more years of data with improved event selection and reconstruction
techniques, the sensitivity was improved by a factor 3.5 or more with respect
to the previously published results obtained with the 40-string configuration
of IceCube. We performed an all-sky survey and a dedicated search using a
catalog of \textit{a priori} selected objects observed by other telescopes. In
both searches, the data are compatible with the background-only hypothesis. In
the absence of evidence for a signal, we set upper limits on the flux of muon
neutrinos. For an E$^{-2}$ neutrino spectrum, the observed limits are between
0.9 and $23.2\times 10^{-12}$ TeV$^{-1}$ cm$^{-2}$s$^{-1}$. We also report
upper limits for neutrino emission from groups of sources which were selected
according to theoretical models or observational parameters and analysed with a
stacking approach.Comment: 41 pages, 26 figures, submitted to Ap
Unveiling the circumstellar environment towards a massive young stellar
  object

As a continuation of a previous work, in which we found strong evidence of
massive molecular outflows towards a massive star forming site, we present a
new study of this region based on very high angular resolution observations
with the aim of discovering the outflow driven mechanism. Using near-IR data
acquired with Gemini-NIRI at the broad H- and Ks-bands, we study a region of
22" x 22" around the UCHII region G045.47+0.05, a massive star forming site at
the distance of about 8 kpc. To image the source with the highest spatial
resolution possible we employed the adaptative optic system ALTAIR, achieving
an angular resolution of about 0.15". We discovered a cone-like shape nebula
with an opening angle of about 90 degree extending eastwards the IR source
2MASS J19142564+1109283, a very likely MYSO. This morphology suggests a cavity
that was cleared in the circumstellar material and its emission may arise from
scattered continuum light, warm dust, and likely emission lines from
shock-excited gas. The nebula, presenting arc-like features, is connected with
the IR source through a jet-like structure, which is aligned with the blue
shifted CO outflow found in a previous study. The near-IR structure lies ~3"
north of the radio continuum emission, revealing that it is not spatially
coincident with the UCHII region. The observed morphology and structure of the
near-IR nebula strongly suggest the presence of a precessing jet. In this study
we have resolved the circumstellar ambient (in scale of a thousand A.U.) of a
distant MYSO, indeed one of the farthest cases.Comment: Accepted in A&A Letters (October 2013
Towards a fitting procedure to deeply virtual meson production -- the
  next-to-leading order case --

Based on the collinear factorization approach, we present a comprehensive
perturbative next-to-leading (NLO) analysis of deeply virtual meson production
(DVMP). Our representation in conformal Mellin space can serve as basis for a
global fitting procedure to access generalized parton distributions from
experimental measurements of DVMP and deeply virtual Compton scattering (DVCS).
We introduce a rather general formalism for the evaluation of conformal moments
that can be developed further beyond the considered order. We also confirm
previous diagrammatical findings in the pure singlet quark channel. Finally, we
use the analytic properties of the hard scattering amplitudes to estimate
qualitatively the size of radiative corrections and illustrate these
considerations with some numerical examples. The results suggest that global
NLO GPD fits, including both DVMP and DVCS data, could be more stable than
often feared.Comment: 125 pages, 7 figures, 8 table
5D partition functions, q-Virasoro systems and integrable spin-chains

We analyze N = 1 theories on S5 and S4 x S1, showing how their partition
functions can be written in terms of a set of fundamental 5d holomorphic
blocks. We demonstrate that, when the 5d mass parameters are analytically
continued to suitable values, the S5 and S4 x S1 partition functions degenerate
to those for S3 and S2 x S1. We explain this mechanism via the recently
proposed correspondence between 5d partition functions and correlators with
underlying q-Virasoro symmetry. From the q-Virasoro 3-point functions, we
axiomatically derive a set of associated reflection coefficients, and show they
can be geometrically interpreted in terms of Harish-Chandra c-functions for
quantum symmetric spaces. We then link these particular c-functions to the
types appearing in the Jost functions encoding the asymptotics of the
scattering in integrable spin chains, obtained taking different limits of the
XYZ model to XXZ-type.Comment: 58 pages, 2 figures, pdfLaTeX; v2: references added, comments adde
Accelerating Cosmic Microwave Background map-making procedure through
  preconditioning

Estimation of the sky signal from sequences of time ordered data is one of
the key steps in Cosmic Microwave Background (CMB) data analysis, commonly
referred to as the map-making problem. Some of the most popular and general
methods proposed for this problem involve solving generalised least squares
(GLS) equations with non-diagonal noise weights given by a block-diagonal
matrix with Toeplitz blocks. In this work we study new map-making solvers
potentially suitable for applications to the largest anticipated data sets.
They are based on iterative conjugate gradient (CG) approaches enhanced with
novel, parallel, two-level preconditioners. We apply the proposed solvers to
examples of simulated non-polarised and polarised CMB observations, and a set
of idealised scanning strategies with sky coverage ranging from nearly a full
sky down to small sky patches. We discuss in detail their implementation for
massively parallel computational platforms and their performance for a broad
range of parameters characterising the simulated data sets. We find that our
best new solver can outperform carefully-optimised standard solvers used today
by a factor of as much as 5 in terms of the convergence rate and a factor of up
to $4$ in terms of the time to solution, and to do so without significantly
increasing the memory consumption and the volume of inter-processor
communication. The performance of the new algorithms is also found to be more
stable and robust, and less dependent on specific characteristics of the
analysed data set. We therefore conclude that the proposed approaches are well
suited to address successfully challenges posed by new and forthcoming CMB data
sets.Comment: 19 pages // Final version submitted to A&
Aspects of Electric and Magnetic Variables in SU(2) Yang-Mills Theory

We introduce a novel decomposition of the four dimensional SU(2) gauge field.
This decomposition realizes explicitely a symmetry between electric and
magnetic variables, suggesting a duality picture between the corresponding
phases. It also indicates that at large distances the Yang-Mills theory
involves a three component unit vector field, a massive Lorentz vector field,
and a neutral scalar field that condenses which yields the mass scale. Our
results are consistent with the proposal that the physical spectrum of the
theory contains confining strings which are tied into stable knotted solitons.Comment: we have made substantial improvement
SUSY 3D Georgi-Glashow model at finite temperature

We study the finite-temperature properties of the supersymmetric version of
(2+1)D Georgi-Glashow model. As opposed to its nonsupersymmetric counterpart,
the parity symmetry in this theory at zero temperature is spontaneously broken
by the bilinear photino condensate. We find that as the temperature is raised,
the deconfinement and the parity restoration occur in this model at the same
point $T_c=g^2/8\pi$. The transition is continuous, but is not of the Ising
type as in nonsupersymmetric Georgi-Glashow model, but rather of the
Berezinsky-Kosterlitz-Thouless type as in $Z_4$-invariant spin model.Comment: 8 pages, LaTeX2e, no figure
Coherent States of the Deformed Heisenberg-Weyl Algebra in
  Noncommutative Space

In two-dimensional space a subtle point that for the case of both space-space
and momentum-momentum noncommuting, different from the case of only space-space
noncommuting, the deformed Heisenberg-Weyl algebra in noncommutative space is
not completely equivalent to the undeformed Heisenberg-Weyl algebra in
commutative space is clarified. It follows that there is no well defined
procedure to construct the deformed position-position coherent state or the
deformed momentum-momentum coherent state from the undeformed position-momentum
coherent state. Identifications of the deformed position-position and deformed
momentum-momentum coherent states with the lowest energy states of a cold
Rydberg atom in special conditions and a free particle, respectively, are
demonstrated.Comment: 10 pages, no figur
Production of D$^{**}_{s}$ mesons in hadronic Z decays

The production rates of the orbitally excited Ds** mesons, Ds1 and Ds2*, are measured with the 4.1 million hadronic Z decays recorded by the ALEPH detector during 1991--1995. The Ds** mesons are reconstructed in the decay modes Ds1+ -> D*+ K0, Ds1+ -> D*0 K+ and Ds2*+ -> D0 K+. The production rate of the Ds1 is measured to be n(Z->Ds1+-)=(0.52+-0.09+-0.06)%, under the assumption that the two considered decay modes of the Ds1 saturate the branching ratio. The production rate of the Ds2* is determined to be n(Z->Ds2*+-)=(0.83+-0.29+0.07-0.13)%, assuming that the branching fraction of the decay Ds2*+ -> D0 K+ is 45%. The production rates in Z->cc and Z->bbar decays are measured separately
UV and IR behaviour in QFT and LCQFT with fields as Operator Valued
  Distributions:Epstein and Glaser revisited

Following Epstein-Glaser's work we show how a QFT formulation based on
operator valued distributions (OPVD) with adequate test functions treats
original singularities of propagators on the diagonal in a mathematically
rigourous way.Thereby UV and/or IR divergences are avoided at any stage, only a
finite renormalization finally occurs at a point related to the arbitrary scale
present in the test functions.Some well known UV cases are examplified.The
power of the IR treatment is shown for the free massive scalar field theory
developed in the (conventionally hopeless) mass perturbation expansion.It is
argued that the approach should prove most useful for non pertubative methods
where the usual determination of counterterms is elusiveComment: 6 pages 2 columns per pag
A new formulation of the spine approach to branching diffusions

We present a formalization of the spine change of measure approach for
branching diffusions that improves on the scheme laid out for branching
Brownian motion in Kyprianou (2004) ["Travelling wave solutions to the KPP
equation, Ann. Inst. H. Poincare Probab. Statist. 40, no.1, pp53-72] which
itself made use of earlier works of Lyons et al (1997) ["A conceptual proof of
the Kesten-Stigum theorem for multi-type branching processes", Classical and
modern branching processes, IMA Vol. Math. Appl., vol.84, Springer, New York,
pp181-185]. We use our new formulation to interpret certain `Gibbs-Boltzmann'
weightings of particles and use this to give a new, intuitive and proof of a
more general `Many-to-One' result which enables expectations of sums over
particles in the branching diffusion to be calculated purely in terms of an
expectation of one particle. Significantly, our formalization has provided the
foundations that facilitate a variety of new, greatly simplified and more
intuitive proofs in branching diffusions: see, for example, the L^p convergence
of additive martingales in Hardy and Harris (2006) ["Spine proofs for
L^p-convergence of branching-diffusion martingales", arXiv:math.PR/0611056],
the path large deviation results for branching Brownian motion in Hardy and
Harris (2006) ["A conceptual approach to a path result for branching Brownian
motion", Stochastic Processes and their Applications,
doi:10.1016/j.spa.2006.05.010] and the large deviations for a continuous-typed
branching diffusion in Git et al (2006) ["Exponential growth rates in a typed
branching diffusion", Annals Applied Prob., (under revision)] and Hardy and
Harris (2004) ["A spine proof of a lower-bound for a typed branching
diffusion", no.0408, Mathematics Preprint, University of Bath].Comment: 24 page
Interference of spontaneously emitted photons

We discuss an experimental setup where two laser-driven atoms spontaneously
emit photons and every photon causes a ``click'' at a point on a screen. By
deriving the probability density for an emission into a certain direction from
basic quantum mechanical principles we predict a spatial interference pattern.
Similarities and differences with the classical double-slit experiment are
discussed.Comment: 6 pages, 2 figures, contribution to the symposium "100 Years of
  Werner Heisenberg - Works and Impact" in Bamberg, to appear in Fortschritte
  der Physi
State preparation by photon filtering

We propose a setup capable of generating Fock states of a single mode
radiation field. The scheme is based on coupling the signal field to a ring
cavity through cross-Kerr phase modulation, and on conditional ON-OFF
photodetection at the output cavity mode. The same setup allows to prepare
selected superpositions of Fock states and entangled two-mode states.
Remarkably, the detector's quantum efficiency does not affect the reliability
of the state synthesis.Comment: Paper submitted to the proceedings of the III Adriatico Research
  Conference on Quantum Interferometry, ICTP, March 1-5,1999. 9 pages, 10 eps
  figure
A comparison of international HRM practices by Indian and European MNEs : evidence from Africa

By comparing the HRM practices in Indian and European MNE subsidiaries located in four of the Southern African Development Community countries, this paper tests the relevance of the country of origin effect and analyses the strength of institutional and firm level influences. Examining data from 865 MNE subsidiaries obtained from the World Bank enterprise survey data, the paper finds that Indian MNEs have higher labour costs in relation to total sales than their European counterparts, that Indian MNEs make more use of temporary labour than their European counterparts, that Indian MNEs invest in less training than their European counterparts. No support is found for the hypothesis that Indian MNEs have a lower ratio of skilled workers in comparison to European-owned subsidiaries. The study shows that country of origin effects are weakened if they are not consistent with host country ideology and that as economies evolve so too do their expectations of HR policy and practices
Learning investments and organizational capabilities: case studies on the development of project portfolio management capabilities

Purpose The purpose of this paper is to improve understanding and provide guidance for investments in organizational learning mechanisms for the establishment and evolution of organizational capabilities such as project portfolio management (PPM) and project management capabilities. Design/methodology/approach A multiple-case study research project investigates the development of PPM capabilities in six successful organizations across diverse industries. Findings The research indicates that PPM and organizational learning are dynamic capabilities that enhance an organization's ability to achieve and maintain competitive advantage in dynamic environments. PPM capabilities are shown to co-evolve through a combination of tacit experience accumulation, explicit knowledge articulation and explicit knowledge codification learning mechanisms. Although all three learning mechanisms are important throughout the establishment and evolution of PPM capability development, the research indicates that the development of an effective PPM capability will require particularly strong investments in enhancing tacit experience accumulation mechanisms and explicit knowledge codification mechanisms during the initial establishment or during periods of radical change to the PPM process
Measurement of the forward-backward asymmetry of electron and muon
  pair-production in $pp$ collisions at $\sqrt{s}$ = 7 TeV with the ATLAS
  detector

This paper presents measurements from the ATLAS experiment of the
forward-backward asymmetry in the reaction $pp\rightarrow
Z/\gamma^{*}\rightarrow l^{+}l^{-}$, with $l$ being electrons or muons, and the
extraction of the effective weak mixing angle. The results are based on the
full set of data collected in 2011 in $pp$ collisions at the LHC at $\sqrt{s}$
= 7 TeV, corresponding to an integrated luminosity of 4.8 fb$^{-1}$. The
measured asymmetry values are found to be in agreement with the corresponding
Standard Model predictions. The combination of the muon and electron channels
yields a value of the effective weak mixing angle of $0.2308 \pm 0.0005
\mathrm{(stat.)} \pm 0.0006 \mathrm{(syst.)} \pm 0.0009\mathrm{(PDF)}$, where
the first uncertainty corresponds to data statistics,the second to systematic
effects and the third to knowledge of the parton density functions. This result
agrees with the current world average from the Particle Data Group fit.Comment: 27 pages plus author list + cover page (44 pages total), 7 figures, 4
  tables, submitted to JHEP, All figures including auxiliary figures are
  available at
  http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2011-34
Rational quantum integrable systems of D_N type with polarized spin
  reversal operators

We study the spin Calogero model of D_N type with polarized spin reversal
operators, as well as its associated spin chain of Haldane-Shastry type, both
in the antiferromagnetic and ferromagnetic cases. We compute the spectrum and
the partition function of the former model in closed form, from which we derive
an exact formula for the chain's partition function in terms of products of
partition functions of Polychronakos-Frahm spin chains of type A. Using a
recursion relation for the latter partition functions that we derive in the
paper, we are able to numerically evaluate the partition function, and thus the
spectrum, of the D_N-type spin chain for relatively high values of the number
of spins N. We analyze several global properties of the chain's spectrum, such
as the asymptotic level density, the distribution of consecutive spacings of
the unfolded spectrum, and the average degeneracy. In particular, our results
suggest that this chain is invariant under a suitable Yangian group, and that
its spectrum coincides with that of a Yangian-invariant vertex model with
linear energy function and dispersion relation.Comment: 26 pages, 5 figures, typeset in LaTe
Heavy neutrinos and the $pp\to lljj$ CMS data

We show that the excess in the $pp \to ee jj$ CMS data can be naturally
interpreted within the Minimal Left Right Symmetric model (MLRSM), keeping $g_L
= g_R$, if CP phases and non-degenerate masses of heavy neutrinos are taken
into account. As an additional benefit, a natural interpretation of the
reported ratio (14:1) of the opposite-sign (OS) $pp\to l^\pm l^\mp jj$ to the
same-sign (SS) $pp\to l^\pm l^\pm jj$ lepton signals is possible. Finally, a
suppression of muon pairs with respect to electron pairs in the $pp \to lljj$
data is obtained, in accordance with experimental data. If the excess in the
CMS data survives in the future, it would be a first clear hint towards
presence of heavy neutrinos in right-handed charged currents with specific CP
phases, mixing angles and masses, which will have far reaching consequences for
particle physics directions.Comment: 8 pages, 7 figures. v2: minor changes, refs added, typos corrected,
  version accepted for publication in PL
The parity-preserving massive QED3: vanishing beta-function and no
  parity anomaly

The parity-preserving massive QED3 exhibits vanishing gauge coupling
beta-function and is parity and infrared anomaly free at all orders in
perturbation theory. Parity is not an anomalous symmetry, even for the
parity-preserving massive QED3, in spite of some claims about the possibility
of a perturbative parity breakdown, called parity anomaly. The proof is done by
using the algebraic renormalization method, which is independent of any
regularization scheme, based on general theorems of perturbative quantum field
theory.Comment: In honor of Prof. Raymond Stora (1930-2015), to appear in Phys. Lett.
  B, 5 page