20,748 research outputs found
Heavy Vector Triplets: Bridging Theory and Data
We introduce a model-independent strategy to study narrow resonances which we
apply to a heavy vector triplet of the Standard Model (SM) group for
illustration. The method is based on a simplified phenomenological Lagrangian
which reproduces a large class of explicit models. Firstly, this allows us to
derive robust model-independent phenomenological features and, conversely, to
identify the peculiarities of different explicit realizations. Secondly, limits
on cross-section times BR can be converted into bounds on a few relevant
parameters in a fully analytic way, allowing for an interpretation in any given
explicit model. Based on the available 8 TeV LHC analyses, we derive current
limits and interpret them for vector triplets arising in weakly coupled (gauge)
and strongly coupled (composite) extensions of the SM. We point out that a
model-independent limit setting procedure must be based on purely on-shell
quantities, like a cross-section times BR. Finite width effects altering the
limits can be considerably reduced by focusing on the on-shell signal region.
We illustrate this aspect with a study of the invariant mass distribution in
di-lepton searches and the transverse mass distribution in lepton-neutrino
final states. In addition to this paper we provide a set of online tools
available at a dedicated webpage.Comment: 53 pages, 10 figures; references added, typos corrected; published
versio
Methods of power line interference elimination in EMG signals
Electromyogram (EMG) recordings are often corrupted by the wide range of artifacts, which one of them is power line interference (PLI). The study focuses on some of the well-known signal processing approaches used to eliminate or attenuate PLI from EMG signal. The results are compared using signal-to-noise ratio (SNR), correlation coefficients and Bland-Altman analysis for each tested method: notch filter, adaptive noise canceller (ANC) and wavelet transform (WT). Thus, the power of the remaining noise and shape of the output signal are analysed. The results show that the ANC method gives the best output SNR and lowest shape distortion compared to the other methods.Web of Science40706
The HLMA project: determination of high delta-m^2 LMA mixing parameters and constraint on |U_e3| with a new reactor neutrino experiment
In the forthcoming months, the KamLAND experiment will probe the parameter
space of the solar large mixing angle (LMA) MSW solution as the origin of the
solar neutrino deficit with \nuebar's from distant nuclear reactors. If
however the solution realized in nature is such that \Dm2_{sol} \gsim 2 \cdot
10^{-4} eV (thereafter named the HLMA region), KamLAND will only observe a
rate suppression but no spectral distortion and hence it will not have the
optimal sensitivity to measure the mixing parameters. In this case, we propose
a new medium baseline reactor experiment located at Heilbronn (Germany) to pin
down the precise value of the solar mixing parameters. In this paper, we
present the Heilbronn detector site, we calculate the \nuebar interaction
rate and the positron spectrum expected from the surrounding nuclear power
plants. We also discuss the sensitivity of such an experiment to |U_e3| in both
normal and inverted neutrino mass hierarchy scenarios. We then outline the
detector design, estimate background signals induced by natural radioactivity
as well as by in-situ cosmic ray muon interaction, and discuss a strategy to
detect the anti-neutrino signal 'free of background'.Comment: 22 pages, 5 figures; v2: added references, caption of Fig.4 and typos
corrected; v3: accepted for publication in Astroparticle Physics, references
added, typo in Sec. 6.3 correcte
Possible Suppression of Resonant Signals for Split-UED by Mixing at the LHC?
The mixing of the imaginary parts of the transition amplitudes of nearby
resonances via the breakdown of the Breit-Wigner approximation has been shown
to lead to potentially large modifications in the signal rates for new physics
at colliders. In the case of suppression, this effect may be significant enough
to lead to some new physics signatures being initially missed in searches at,
e.g., the LHC. Here we explore the influence of this `width mixing' on the
production of the nearly degenerate, level-2 Kaluza-Klein (KK) neutral gauge
bosons present in Split-UED. We demonstrate that in this particular case large
cross section modifications in the resonance region are necessarily absent and
explain why this is so based on the group theoretical structure of the SM.Comment: 10 pages, 2 figures; discussion and references adde
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