55 research outputs found
Possibility of hypothetical stable micro black hole production at future 100 TeV collider
We study the phenomenology of TeV-scale black holes predicted in theories
with large extra dimensions, under the further assumption that they are
absolutely stable. Our goal is to present an exhaustive analysis of safety of
the proposed 100 TeV collider, as it was done in the case of the LHC. We
consider the theories with different number of extra dimensions and identify
those for which a possible accretion to macroscopic size would have timescales
shorter than the lifetime of the Solar system. We calculate the cross sections
of the black hole production at the proposed 100 TeV collider, the fraction of
the black holes trapped inside the Earth and the resulting rate of capture
inside the Earth via an improved method. We study the astrophysical
consequences of stable micro black holes existence, in particular its influence
on the stability of white dwarfs and neutron stars. We obtain constraints for
the previously unexplored range of higher-dimensional Planck mass values.
Several astrophysical scenarios of the micro black hole production, which were
not considered before, are taken into account. Finally, using the astrophysical
constraints we consider the implications for future 100 TeV terrestrial
experiments. We exclude the possibility of the charged stable micro black holes
production.Comment: 11 pages, 8 figures, accepted for publication in EPJ
Generic axion Maxwell equations: path integral approach
Using the path integral approach, we derive the low energy interactions
between axions and electromagnetic field that arise in models with heavy dyons
charged under a spontaneously broken global axial symmetry. Hence, we
obtain generic axion-Maxwell equations relevant for experimental searches. We
find that the structure of the axion Maxwell equations could be significantly
different compared to what is normally assumed in the literature, as the
derived equations feature new axion-dependent terms including CP-violating
ones. The new terms can reconcile the Peccei-Quinn solution to the strong CP
problem with astrophysical axion hints, as well as give unique signatures in
light-shining-through-wall and haloscope experiments. Moreover, via the latter
signatures, these experiments can indirectly probe the existence of heavy
dyons.Comment: Accepted for publication in Annalen der Physik; an appendix is added
where we give a mathematical proof disproving the claim that the theta-term
in a U(1) gauge theory generates electric charge proportional to theta for
every magnetic monopole of the theory; 22 page
Photophilic hadronic axion from heavy magnetic monopoles
We propose a model for the QCD axion which is realized through a coupling of
the Peccei-Quinn scalar field to magnetically charged fermions at high
energies. We show that the axion of this model solves the strong CP problem and
then integrate out heavy magnetic monopoles using the Schwinger proper time
method. We find that the model discussed yields axion couplings to the Standard
Model which are drastically different from the ones calculated within the
KSVZ/DFSZ-type models, so that large part of the corresponding parameter space
can be probed by various projected experiments. Moreover, the axion we
introduce is consistent with the astrophysical hints suggested both by
anomalous TeV-transparency of the Universe and by excessive cooling of
horizontal branch stars in globular clusters. Assuming infrared Abelian
dominance in QCD, we show that the leading term for the cosmic axion abundance
is not changed compared to the conventional pre-inflationary QCD axion case for
much of the allowed parameter space.Comment: 22 pages, 2 figure
Searching for GUT-scale QCD Axions and Monopoles with a High Voltage Capacitor
The QCD axion has been postulated to exist because it solves the strong CP
problem. Furthermore, if it exists axions should be created in the early
Universe and could account for all the observed dark matter. In particular,
axion masses of order to eV correspond to axions in the
vicinity of the GUT-scale. In this mass range many experiments have been
proposed to search for the axion through the standard QED coupling parameter
. Recently axion electrodynamics has been expanded to
include two more coupling parameters, and , which could
arise if heavy magnetic monopoles exist. In this work we show that both
and may be searched for using a high voltage capacitor.
Since the experiment is not sensitive to , it gives a new
way to search for effects of heavy monopoles if the GUT-scale axion is shown to
exist, or to simultaneously search for both the axion and the monopole at the
same time
Распознавание породного и возрастного состава древостоев с использованием алгоритмов на основе самокорректирующихся кодов
The basic model of the recognition of forest inventory characteristics using spectral features
is represented in the framework of the problem of hyperspectral airborne imagery processing.
The algorithm of multiclass supervised classification based on the error-correcting output codes
underlies this model. The support vector machine method is used as the necessary binary classifier.
The method of the construction of training set by using mixed forest plots is represented. Results
of the retrieval of species and age composition of forest stands from hyperspectral images are
represented for the selected test area. The estimate of accuracy of the retrieval of the mixed forest
composition is comparable with the accuracy of ground-based forest inventory dataПредставлена базовая модель распознавания таксационных характеристик древостоев
по спектральным признакам в проблеме обработки гиперспектральных авиационных
изображений. Основу модели составляет алгоритм многоклассовой обучаемой классификации
с использованием самокорректирующихся кодов. В качестве необходимого метода бинарной
классификации применен метод опорных векторов. Описана методика использования выделов
со смешанным породным составом для построения обучающего ансамбля. Приведен пример
восстановления породного и возрастного состава для выбранного тестового участка по
данным гиперспектральных измерений. Оценка точности восстановления породного состава
соответствует точности наземных данных лесотаксаци
The Spin Structure of the Nucleon
We present an overview of recent experimental and theoretical advances in our
understanding of the spin structure of protons and neutrons.Comment: 84 pages, 29 figure
Letter of interest for a neutrino beam from Protvino to KM3NeT/ORCA
The Protvino accelerator facility located in the Moscow region, Russia, is in a good position to offer a rich experimental research program in the field of neutrino physics. Of particular interest is the possibility to direct a neutrino beam from Protvino towards the KM3NeT/ORCA detector, which is currently under construction in the Mediterranean Sea 40 km offshore Toulon, France. This proposal is known as P2O. Thanks to its baseline of 2595 km, this experiment would yield an unparalleled sensitivity to matter effects in the Earth, allowing for the determination of the neutrino mass ordering with a high level of certainty after only a few years of running at a modest beam intensity of ≈ 90 kW. With a prolonged exposure (≈1500 kWyear), a 2σ sensitivity to the leptonic CP-violating Dirac phase can be achieved. A second stage of the experiment, comprising a further intensity upgrade of the accelerator complex and a densified version of the ORCA detector (Super-ORCA), would allow for up to a 6σ sensitivity to CP violation and a 10º−17º resolution on the CP phase after 10 years of running with a 450 kW beam, competitive with other planned experiments. The initial composition and energy spectrum of the neutrino beam would need to be monitored by a near detector, to be constructed several hundred meters downstream from the proton beam target. The same neutrino beam and near detector set-up would also allow for neutrino-nucleus cross section measurements to be performed. A short-baseline sterile neutrino search experiment would also be possible
Inferring causal molecular networks: empirical assessment through a community-based effort
Inferring molecular networks is a central challenge in computational biology. However, it has remained unclear whether causal, rather than merely correlational, relationships can be effectively inferred in complex biological settings. Here we describe the HPN-DREAM network inference challenge that focused on learning causal influences in signaling networks. We used phosphoprotein data from cancer cell lines as well as in silico data from a nonlinear dynamical model. Using the phosphoprotein data, we scored more than 2,000 networks submitted by challenge participants. The networks spanned 32 biological contexts and were scored in terms of causal validity with respect to unseen interventional data. A number of approaches were effective and incorporating known biology was generally advantageous. Additional sub-challenges considered time-course prediction and visualization. Our results constitute the most comprehensive assessment of causal network inference in a mammalian setting carried out to date and suggest that learning causal relationships may be feasible in complex settings such as disease states. Furthermore, our scoring approach provides a practical way to empirically assess the causal validity of inferred molecular networks
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