5,112 research outputs found
ScannerS: Constraining the phase diagram of a complex scalar singlet at the LHC
We present the first version of a new tool to scan the parameter space of
generic scalar potentials, ScannerS. The main goal of ScannerS is to help
distinguish between different patterns of symmetry breaking for each scalar
potential. In this work we use it to investigate the possibility of excluding
regions of the phase diagram of several versions of a complex singlet extension
of the Standard Model, with future LHC results. We find that if another scalar
is found, one can exclude a phase with a dark matter candidate in definite
regions of the parameter space, while predicting whether a third scalar to be
found must be lighter or heavier. The first version of the code is publicly
available and contains various generic core routines for tree level vacuum
stability analysis, as well as implementations of collider bounds, dark matter
constraints, electroweak precision constraints and tree level unitarity.Comment: 24 pages, 4 figures, 3 tables. Project development webpage -
http://gravitation.web.ua.pt/Scanner
NLO electroweak corrections in general scalar singlet models
If no new physics signals are found, in the coming years, at the Large Hadron
Collider Run-2, an increase in precision of the Higgs couplings measurements
will shift the dicussion to the effects of higher order corrections. In Beyond
the Standard Model (BSM) theories this may become the only tool to probe new
physics. Extensions of the Standard Model (SM) with several scalar singlets may
address several of its problems, namely to explain dark matter, the
matter-antimatter asymmetry, or to improve the stability of the SM up to the
Planck scale. In this work we propose a general framework to calculate one
loop-corrections in BSM models with an arbitrary number of scalar singlets. We
then apply our method to a real and to a complex scalar singlet models. We
assess the importance of the one-loop radiative corrections first by computing
them for a tree level mixing sum constraint, and then for the main Higgs
production process . We conclude that, for the currently allowed
parameter space of these models, the corrections can be at most a few percent.
Notably, a non-zero correction can survive when dark matter is present, in the
SM-like limit of the Higgs couplings to other SM particles.Comment: 35 pages, 3 figure
Wrong sign and symmetric limits and non-decoupling in 2HDMs
We analyse the possibility that, in two Higgs doublet models, one or more of
the Higgs couplings to fermions or to gauge bosons change sign, relative to the
respective Higgs Standard Model couplings. Possible sign changes in the
coupling of a neutral scalar to charged ones are also discussed. These
\textit{wrong signs} can have important physical consequences, manifesting
themselves in Higgs production via gluon fusion or Higgs decay into two gluons
or into two photons. We consider all possible wrong sign scenarios, and also
the \textit{symmetric limit}, in all possible Yukawa implementations of the two
Higgs doublet model, in two different possibilities: the observed Higgs boson
is the lightest CP-even scalar, or the heaviest one. We also analyse thoroughly
the impact of the currently available LHC data on such scenarios. With all 8
TeV data analysed, all wrong sign scenarios are allowed in all Yukawa types,
even at the 1 level. However, we will show that B-physics constraints
are crucial in excluding the possibility of wrong sign scenarios in the case
where is below 1. We will also discuss the future prospects for
probing the wrong sign scenarios at the next LHC run. Finally we will present a
scenario where the alignment limit could be excluded due to non-decoupling in
the case where the heavy CP-even Higgs is the one discovered at the LHC.Comment: 20 pages, 15 figure
Discrete-Time Fractional Variational Problems
We introduce a discrete-time fractional calculus of variations on the time
scale , . First and second order necessary optimality
conditions are established. Examples illustrating the use of the new
Euler-Lagrange and Legendre type conditions are given. They show that solutions
to the considered fractional problems become the classical discrete-time
solutions when the fractional order of the discrete-derivatives are integer
values, and that they converge to the fractional continuous-time solutions when
tends to zero. Our Legendre type condition is useful to eliminate false
candidates identified via the Euler-Lagrange fractional equation.Comment: Submitted 24/Nov/2009; Revised 16/Mar/2010; Accepted 3/May/2010; for
publication in Signal Processing
Deposit Growth in the Wetting of an Angular Region with Uniform Evaporation
Solvent loss due to evaporation in a drying drop can drive capillary flows
and solute migration. The flow is controlled by the evaporation profile and the
geometry of the drop. We predict the flow and solute migration near a sharp
corner of the perimeter under the conditions of uniform evaporation. This
extends the study of Ref. 6, which considered a singular evaporation profile,
characteristic of a dry surrounding surface. We find the rate of the deposit
growth along contact lines in early and intermediate time regimes. Compared to
the dry-surface evaporation profile of Ref. 6, uniform evaporation yields more
singular deposition in the early time regime, and nearly uniform deposition
profile is obtained for a wide range of opening angles in the intermediate time
regime. Uniform evaporation also shows a more pronounced contrast between acute
opening angles and obtuse opening angles.Comment: 12 figures, submitted to Physical Review
Temporal patterns in acoustic presence and foraging activity of oceanic dolphins at seamounts in the Azores
© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Cascao, I., Lammers, M. O., Prieto, R., Santos, R. S., & Silva, M. A. Temporal patterns in acoustic presence and foraging activity of oceanic dolphins at seamounts in the Azores. Scientific Reports, 10(1), (2020): 3610, doi:10.1038/s41598-020-60441-4.Several seamounts have been identified as hotspots of marine life in the Azores, acting as feeding stations for top predators, including cetaceans. Passive acoustic monitoring is an efficient tool to study temporal variations in the occurrence and behaviour of vocalizing cetacean species. We deployed bottom-moored Ecological Acoustic Recorders (EARs) to investigate the temporal patterns in acoustic presence and foraging activity of oceanic dolphins at two seamounts (Condor and Gigante) in the Azores. Data were collected in March–May 2008 and April 2010–February 2011. Dolphins were present year round and nearly every day at both seamounts. Foraging signals (buzzes and bray calls) were recorded in >87% of the days dolphin were present. There was a strong diel pattern in dolphin acoustic occurrence and behaviour, with higher detections of foraging and echolocation vocalizations during the night and of social signals during daylight hours. Acoustic data demonstrate that small dolphins consistently use Condor and Gigante seamounts to forage at night. These results suggest that these seamounts likely are important feeding areas for dolphins. This study contributes to a better understanding of the feeding ecology of oceanic dolphins and provides new insights into the role of seamount habitats for top predators.This research was supported by the Fundação para a Ciência e a Tecnologia (FCT), Azores 2020 Operational Programme and the Fundo Regional da Ciência e Tecnologia (FRCT), through research projects TRACE (PTDC/MAR/74071/2006), MAPCET (M2.1.2/F/012/2011), FCT-Exploratory (IF/00943/2013/CP1199/CT0001), WATCH IT (Acores-01-0145-FEDER-000057) and MISTIC SEAS II (GA11.0661/2017/750679/SUB/ENV.C2), co-funded by FEDER, COMPETE, QREN, POPH, European Social Fund (ESF), the Portuguese Ministry for Science and Education, and EU-DG/ENV. The Azores 2020 Operational Programme is funded by the community structural funds ERDF and ESF. Funds were also provided by FCT to MARE, through the strategic project UID/MAR/04292/2013. MAS was supported through a FCT Investigator contract funded by POPH, QREN, ESF and the Portuguese Ministry for Science and Education (IF/00943/2013). IC was supported by a FCT doctoral grant (SFRH/BD/41192/2007) and RP by a FCT postdoctoral grant (SFRH/BPD/108007/2015). We thank the field and crew teams for assisting with the many deployments and recoveries of the EARs. Special thanks to Norberto Serpa for helping with mooring design, Ken Sexton and Michael Richlen for their roles in manufacturing the EARs, Sergio Gomes for building the battery packs, and Lisa Munger for adapting Triton for EAR data analysis
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