7,255 research outputs found
Signs of heavy Higgs bosons at CLIC: An road to the Electroweak Phase Transition
We analyse the sensitivity of the proposed Compact Linear Collider (CLIC) to
the existence of beyond the Standard Model (SM) Higgs bosons through their
decays into pairs of massive gauge bosons and SM-like Higgses , considering CLIC centre of mass energies TeV and TeV.
We find that resonant di-Higgs searches at CLIC would allow for up to two
orders of magnitude improvement w.r.t. the sensitivity achievable by HL-LHC in
the mass range . Focusing then
on a real singlet extension of the SM, we explore the prospects of heavy Higgs
searches at CLIC for probing the regions of parameter space yielding a strongly
first order electroweak phase transition that could generate the observed
matter-antimatter asymmetry of the Universe. Our study illustrates the
complementarity between CLIC and other possible future colliders like FCC-ee in
probing singlet extensions of the SM, and shows that high-energy
colliders provide a powerful means to unravel the nature of electroweak
symmetry breaking in the early Universe.Comment: 27 pages, 15 figure
A strong electroweak phase transition in the 2HDM after LHC8
The nature of the electroweak phase transition in two-Higgs-doublet models is revisited in light of the recent LHC results. A scan over an extensive region of their parameter space is performed, showing that a strongly first-order phase transition favours a light neutral scalar with SM-like properties, together with a heavy pseudo-scalar (m_A^0 > 400 GeV) and a mass hierarchy in the scalar sector, m_H^+ gamma gamma decay channel and find that an enhancement in the branching ratio is allowed, and in some cases even preferred, when a strongly first-order phase transition is required
Echoes of the electroweak phase transition: discovering a second Higgs doublet through A0 → ZH0
The existence of a second Higgs doublet in nature could lead to a cosmological first-order electroweak
phase transition and explain the origin of the matter-antimatter asymmetry in the Universe. We obtain the
spectrum and properties of the new scalars H0, A0, and H� that signal such a phase transition and show that
the observation of the decay A0 → ZH0 at LHC would be a “smoking gun” signature of these scenarios. We
analyze the LHC search prospects for this decay in the llbb¯ and llWþW− final states, arguing that current
data may be sensitive to this signature in the former channel as well as there being great potential for a
discovery in either channel at the very early stages of the 14 TeV run
Role models for complex networks
We present a framework for automatically decomposing ("block-modeling") the
functional classes of agents within a complex network. These classes are
represented by the nodes of an image graph ("block model") depicting the main
patterns of connectivity and thus functional roles in the network. Using a
first principles approach, we derive a measure for the fit of a network to any
given image graph allowing objective hypothesis testing. From the properties of
an optimal fit, we derive how to find the best fitting image graph directly
from the network and present a criterion to avoid overfitting. The method can
handle both two-mode and one-mode data, directed and undirected as well as
weighted networks and allows for different types of links to be dealt with
simultaneously. It is non-parametric and computationally efficient. The
concepts of structural equivalence and modularity are found as special cases of
our approach. We apply our method to the world trade network and analyze the
roles individual countries play in the global economy
A dynamical system approach to higher order gravity
The dynamical system approach has recently acquired great importance in the
investigation on higher order theories of gravity. In this talk I review the
main results and I give brief comments on the perspectives for further
developments.Comment: 6 pages, 1 figure, 2 tables, talk given at IRGAC 2006, July 200
Some Cosmological Implications of Hidden Sectors
We discuss some cosmological implications of extensions of the Standard Model
with hidden sector scalars coupled to the Higgs boson. We put special emphasis
on the conformal case, in which the electroweak symmetry is broken radiatively
with a Higgs mass above the experimental limit. Our refined analysis of the
electroweak phase transition in this kind of models strengthens the prediction
of a strongly first-order phase transition as required by electroweak
baryogenesis. We further study gravitational wave production and the
possibility of low-scale inflation as well as a viable dark matter candidate.Comment: 23 pages, 8 figures; some comments added, published versio
Variational calculations on the hydrogen molecular ion
We present high-precision non-relativistic variational calculations of bound
vibrational-rotational state energies for the and molecular
ions in each of the lowest electronic states of , , and
symmetry. The calculations are carried out including coupling between
and states but without using the Born-Oppenheimer or any
adiabatic approximation. Convergence studies are presented which indicate that
the resulting energies for low-lying levels are accurate to about .
Our procedure accounts naturally for the lambda-doubling of the state.Comment: 23 pp., RevTeX, epsf.sty, 5 figs. Enhanced data in Table II, dropped
3 figs. from previous versio
A Hierarchical Emotion Regulated Sensorimotor Model: Case Studies
Inspired by the hierarchical cognitive architecture and the perception-action
model (PAM), we propose that the internal status acts as a kind of
common-coding representation which affects, mediates and even regulates the
sensorimotor behaviours. These regulation can be depicted in the Bayesian
framework, that is why cognitive agents are able to generate behaviours with
subtle differences according to their emotion or recognize the emotion by
perception. A novel recurrent neural network called recurrent neural network
with parametric bias units (RNNPB) runs in three modes, constructing a
two-level emotion regulated learning model, was further applied to testify this
theory in two different cases.Comment: Accepted at The 5th International Conference on Data-Driven Control
and Learning Systems. 201
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