3,815 research outputs found
Characterizing Higgs portal dark matter models at the ILC
We study the Dark Matter (DM) discovery prospect and its spin discrimination
in the theoretical framework of gauge invariant and renormalizable Higgs portal
DM models at the ILC with GeV. In such models, the DM pair is
produced in association with a boson. In case the singlet scalar DM, the
mediator is just the SM Higgs boson, whereas for the fermion or vector DM there
is an additional singlet scalar mediator that mixes with the SM Higgs boson,
which produces significant observable differences. After careful investigation
of the signal and backgrounds both at parton level and at detector level, we
find the signal with hadronically decaying boson provides a better search
sensitivity than the signal with leptonically decaying boson. Taking the
fermion DM model as a benchmark scenario, when the DM-mediator coupling
is relatively small, the DM signals are discoverable only for
benchmark points with relatively light scalar mediator . And the spin
discriminating from scalar DM is always promising while it is difficult to
discriminate from vector DM. As for approaching the perturbative
limit, benchmark points with the mediator in the full mass region of
interest are discoverable. And the spin discriminating from both the scalar and
fermion DM are quite promising.Comment: 26 pages, 9 figures, version accepted for publication in EPJ
Scaling quasi-stationary states in long range systems with dissipation
Hamiltonian systems with long-range interactions give rise to long lived out
of equilibrium macroscopic states, so-called quasi-stationary states. We show
here that, in a suitably generalized form, this result remains valid for many
such systems in the presence of dissipation. Using an appropriate mean-field
kinetic description, we show that models with dissipation due to a viscous
damping or due to inelastic collisions admit "scaling quasi-stationary states",
i.e., states which are quasi-stationary in rescaled variables. A numerical
study of one dimensional self-gravitating systems confirms both the relevance
of these solutions, and gives indications of their regime of validity in line
with theoretical predictions. We underline that the velocity distributions
never show any tendency to evolve towards a Maxwell-Boltzmann form.Comment: 5 pages, 3 figures, to appear in Phys. Rev. Let
Tools for producing formal specifications : a view of current architectures and future directions
During the last decade, one important contribution towards requirements engineering has been the advent of formal specification languages. They offer a well-defined notation that can improve consistency and avoid ambiguity in specifications.
However, the process of obtaining formal specifications that are consistent with the requirements is itself a difficult activity. Hence various researchers are developing systems that aid the transition from informal to formal specifications.
The kind of problems tackled and the contributions made by these proposed systems are very diverse. This paper brings these studies together to provide a vision for future architectures that aim to aid the transition from informal to formal specifications. The new architecture, which is based on the strengths of existing studies, tackles a
number of key issues in requirements engineering such as identifying ambiguities, incompleteness, and reusability.
The paper concludes with a discussion of the research problems that need to be addressed in order to realise the proposed architecture
Embedding Riemannian Manifolds by the Heat Kernel of the Connection Laplacian
Given a class of closed Riemannian manifolds with prescribed geometric
conditions, we introduce an embedding of the manifolds into based on
the heat kernel of the Connection Laplacian associated with the Levi-Civita
connection on the tangent bundle. As a result, we can construct a distance in
this class which leads to a pre-compactness theorem on the class under
consideration
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