2,813 research outputs found
Study of corrections for anomalous coupling limits due to the possible background BSM contributions
The search of the anomalous couplings is one of the possible ways to find any
deviation from the Standard Model. The effective field theory is used to
parameterize the anomalous couplings in the Lagrangian with the operators of
higher dimensions, constructed from the SM fields. In the classical way, the
limits on the Wilson coefficients of these operators are set based on beyond
the Standard Model contributions induced for signal process, whereas the ones
induced for background processes are assumed to be negligible. This article
provides a study of the corrections to the limits on Wilson coefficients by
accounting beyond the Standard Model contributions induced for background
processes. The studies of and
productions in collisions with TeV and conditions of the
ATLAS experiment at the LHC are used as example. Cases of collected during Run
II and expected from Run III integrated luminosities of 139 fb and 300
fb are considered. The expected 95% CL limits on coefficients
, , and
are obtained both in classical way and in the way,
where the corrections from background anomalous contributions are applied.
Corrected one-dimensional limits from and
productions are up to 9.1% and 4.4% (depending on
operator) tighter than the classical ones respectively. Corrected combined
limits are up to 3.0% (depending on operator) tighter than the classical ones.
Corrections to two-dimensional limits are also obtained, corrected contours are
more stringent, than the classical ones, and the maximal improvement is of
17.2%
Application of deep learning methods to the study of magnetic phenomena
Nowadays, methods and techniques of Machine Learning and Deep Learning are
being used in various scientific areas. They help to automatize calculations
without losing in quality. In this paper the applying of convolutional neural
network was considered in frame of problems from statistical physics and
computer simulation of magnetic films. In a frame of the first task, CNN was
used to determine critical Curie point for Ising model on 2D square lattice.
Obtained results were compared with classical Monte-Carlo methods and exact
solution. Systems of various lattice sizes and the influence of the size effect
on the results' accuracy were considered. Also, authors considered the
classical two-dimensional Heisenberg model, a spin system with direct
short-range exchange, and studied of its competition with the
Dzyaloshinskii-Moriya interaction. A neural network was applied to the
recognition of Spiral (Sp), Spiral-skyrmion (SpSk) Skyrmion (Sk),
Skyrmion-ferromagnetic (SkF) and Ferromagnetic (FM) phases of the Heisenberg
spin system with magnetic skyrmions. The advantage of CNN's application over
conventional methods for determination of skyrmion's phases was revealed.Comment: 6 pages, 3 figure
Stimulation of reparation in a linear wound model in rats by Bischofit gel
The article is to evaluate Bischofit gel reparative activity in a linear wound model in rat
Search for decay with VES detector
The isospin violating decay has been studied at
VES facility. This study is based at the statistics acquired in
interactions at 27, 36.6 and 41 GeV/c in diffractive reaction . The decay is observed. The ratio of
decay probabilities to is .Comment: 10 pages, 8 figures, presented at XII Conference on Hadron
Spectroscop
Puzzles of Dark Matter - More Light on Dark Atoms?
Positive results of dark matter searches in experiments DAMA/NaI and
DAMA/LIBRA confronted with results of other groups can imply nontrivial
particle physics solutions for cosmological dark matter. Stable particles with
charge -2, bound with primordial helium in O-helium "atoms" (OHe), represent a
specific nuclear-interacting form of dark matter. Slowed down in the
terrestrial matter, OHe is elusive for direct methods of underground Dark
matter detection using its nuclear recoil. However, low energy binding of OHe
with sodium nuclei can lead to annual variations of energy release from OHe
radiative capture in the interval of energy 2-4 keV in DAMA/NaI and DAMA/LIBRA
experiments. At nuclear parameters, reproducing DAMA results, the energy
release predicted for detectors with chemical content other than NaI differ in
the most cases from the one in DAMA detector. Moreover there is no bound
systems of OHe with light and heavy nuclei, so that there is no radiative
capture of OHe in detectors with xenon or helium content. Due to dipole Coulomb
barrier, transitions to more energetic levels of Na+OHe system with much higher
energy release are suppressed in the correspondence with the results of DAMA
experiments. The proposed explanation inevitably leads to prediction of
abundance of anomalous Na, corresponding to the signal, observed by DAMA.Comment: Contribution to Proceedings of XIII Bled Workshop "What Comes beyond
the Standard Model?
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