671 research outputs found
in the complex two Higgs doublet model
The latest LHC data confirmed the existence of a Higgs-like particle and made
interesting measurements on its decays into , , , , and . It is expected that a decay into might be measured at the next LHC round, for which there already exists
an upper bound. The Higgs-like particle could be a mixture of scalar with a
relatively large component of pseudoscalar. We compute the decay of such a
mixed state into , and we study its properties in the context of the
complex two Higgs doublet model, analysing the effect of the current
measurements on the four versions of this model. We show that a measurement of
the rate at a level consistent with the SM can be used
to place interesting constraints on the pseudoscalar component. We also comment
on the issue of a wrong sign Yukawa coupling for the bottom in Type II models.Comment: 31 pages, 15 figure
A reappraisal of the wrong-sign coupling and the study of
It has been pointed out recently that current experiments still allow for a
two Higgs doublet model where the coupling () is
negative; a sign opposite to that of the Standard Model. Due to the importance
of delayed decoupling in the coupling, improved measurements will have a strong impact on this issue. For the
same reason, measurements or even bounds on are
potentially interesting. In this article, we revisit this problem, highlighting
the crucial importance of , which can be understood with
simple arguments. We show that the impacts on models of both and are very sensitive to
input values for the gluon fusion production mechanism; in contrast, and are not. We also
inquire if the search for and its interplay with will impact the sign of the coupling.
Finally, we study these issues in the context of the Flipped two Higgs doublet
model.Comment: 13 pages, pdf figure
Large pseudoscalar Yukawa couplings in the complex 2HDM
We start by presenting the current status of a complex flavour conserving
two-Higgs doublet model. We will focus on some very interesting scenarios where
unexpectedly the light Higgs couplings to leptons and to b-quarks can have a
large pseudoscalar component with a vanishing scalar component. Predictions for
the allowed parameter space at end of the next run with a total collected
luminosity of and are also discussed. These
scenarios are not excluded by present data and most probably will survive the
next LHC run. However, a measurement of the mixing angle , between
the scalar and pseudoscalar component of the 125 GeV Higgs, in the decay will be able to probe many of these scenarios, even with low
luminosity. Similarly, a measurement of in the vertex
could help to constrain the low region in the Type I model.Comment: 21 pages, 10 figure
CP violation in 2HDM and EFT: the ZZZ vertex
We study the CP violating ZZZ vertex in the two-Higgs doublet model, which is
a probe of a Jarlskog-type invariant in the extended Higgs sector. The form
factor is evaluated at one loop in a general gauge and its
magnitude is estimated in the realistic parameter space. Then we turn to the
decoupling limit of the two-Higgs doublet model, where the extra scalars are
heavy and the physics can be described by the Standard Model supplemented by
higher-dimensional operators. The leading operator contributing to at
one loop is identified. The CP violating ZZZ vertex is not generated in the
effective theory by dimension-8 operators, but instead arises only at the
dimension-12 level, which implies an additional suppression by powers of the
heavy Higgs mass scale.Comment: 21 pages; v2: added references and comments, appendix A on method of
regions, and appendix B on derivation of CP-violating effective Lagrangian.
Corrected discussion of dimension-12 operators contributing to ZZZ vertex.
Final JHEP versio
Stochastic impulsive systems driven by renewal processes
Abstract — Necessary and sufficient conditions are provided for stochastic stability and mean exponential stability of impulsive systems with jumps triggered by a renewal process, that is, the intervals between jumps are independent and identically distributed. The conditions for stochastic stability can be efficiently tested in terms of the feasibility of a set of LMIs or in terms of an algebraic test. The relation between the different stability notions for this class of systems is also discussed. The results are illustrated through their application to the stability analysis of networked control systems. We present two benchmark examples for which one can guarantee stability for inter-sampling times roughly twice as large as in a previous paper. I
Control of Impulsive Renewal Systems: Application to Direct Design in Networked Control
Abstract — We consider the control of impulsive systems with jumps triggered by a renewal process, that is, the intervals between jumps are independent and identically distributed. The control action and output measurement are assumed to take place only at jump times. Necessary and sufficient conditions, in the form of LMIs, are given for mean square stabilizability and detectability for the class of systems considered. An infinite horizon quadratic optimal control problem is solved, under appropriate stabilizability and detectability properties. The class of impulsive renewal systems is shown to be especially suited to model networked control systems utilizing CSMA-type protocols, with stochastic intervals between transmissions and packet drops. In this setting, the analysis and synthesis tools mentioned above are used to (i) prove that for an emulationbased design, stability of the closed-loop is preserved if the distribution of the intervals between transmissions assigns high probability to fast sampling (ii) illustrate through a benchmark example the potential advantages of controller direct-design over an emulation-based design. I
A new proof of the Herman-Avila-Bochi formula for Lyapunov exponents of SL(2,R)-cocycles
We study the geometry of the action of SL(2,R) on the projective line in
order to present a new and simpler proof of the Herman-Avila-Bochi formula.
This formula gives the average Lyapunov exponent of a class of 1-families of
SL(2,R)-cocycles.Comment: 13 pages, 2 figure
VCube-PS: A Causal Broadcast Topic-based Publish/Subscribe System
In this work we present VCube-PS, a topic-based Publish/Subscribe system
built on the top of a virtual hypercube-like topology. Membership information
and published messages are broadcast to subscribers (members) of a topic group
over dynamically built spanning trees rooted at the publisher. For a given
topic, the delivery of published messages respects the causal order. VCube-PS
was implemented on the PeerSim simulator, and experiments are reported
including a comparison with the traditional Publish/Subscribe approach that
employs a single rooted static spanning-tree for message distribution. Results
confirm the efficiency of VCube-PS in terms of scalability, latency, number and
size of messages.Comment: Improved text and performance evaluation. Added proof for the
algorithms (Section 3.4
The effect of the availability of student credit on tuition: testing the Bennett hypothesis using evidence from a large-scale student loan program in Brazil
Exploring the expansion of FIES—a large student lending program in Brazil— we test whether eligibility for subsidized student lending causes tuition to rise, in accordance with the Bennett hypothesis. FIES rules created arguably exogenous variation in eligibility across different majors and higher education institutions, which we exploit in a difference-indifferences framework. Using unique information on tuition, we document that FIES eligibility caused tuition to rise. We then estimate a structural demand model to explore whether a reduction in the sensitivity of demand to price increases is one of the possible mechanisms behind this credit-driven tuition rise. Our results show that FIES expansion is associated with a reduction in the tuition elasticity of demand
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