8,804 research outputs found
Supersymmetry without a light Higgs boson at the LHC
We analyze the LHC phenomenology of lambdaSUSY - a version of NMSSM with a
largish SH1H2 coupling. The scalar spectrum of the model contains a 200-300 GeV
Higgs boson h with Standard-Model like properties, and heavy CP-even and CP-odd
Higgs bosons H and A with masses in 500-800 GeV range. We study the discovery
potential of H and A in the decay chains H->hh->4V->2l6j and A->Zh->Z2V->2l4j.
The dominant backgrounds are the diffuse Z6j and Z4j productions, which can be
suppressed by demanding reconstruction of V's and h's in intermediate states.
The excess of signal events allows for a discovery of both H and A with over
5sigma significance for 100 inverse fb of integrated luminosity.Comment: 29 pages, 19 figure
Inflation Targeting in the Context of IMF-Supported Adjustment Programs
This paper analyzes how an inflation targeting regimes relate with the conditioning established in the IMF assistance programs, and, in particular, with its inclusion within the performance criteria associated with that conditioning. The paper analyzes the Brazil's case, the first country in an IMF program to adopt an inflation target, and the lessons that can be derived from this experience. In its last section, we evaluate the idea of using Taylor rules to assess the inflationary performance. Simulations generated by the rule produces are not very similar to the effective policy rates, although differences diminish when expected inflation replaces current inflation within the rule.
Inflation Targeting in the Context of IMF-Supported Adjustment Programs
This paper argues that the IMF's traditional monetary conditionality--a ceiling on net domestic assets of the central bank and a floor on its net international reserves--should be adapted in IMF-supported adjustment programs with countries that have a framework of explicit inflation targets for the implementation of monetary policy. This adaptation should aim at enhancing correspondence and consistency between the monetary objectives of the central bank and the targets established under the IMF-supported adjustment program, as well as between the different instruments used to achieve the policy objectives and targets. The paper reviews various general options in this regard, and, using the case of Brazil as an example, demonstrates how these options may be implemented in practice. . Copyright 2002, International Monetary Fund
Attachment Styles and Communication of Displeasing Truths
This work explores how humans manage the communication of a displeasing and face-threatening truth and how the communicative strategies of the sender and the reaction of the receiver are influenced by their attachment style. Two experimental studies demonstrate that the attachment styles of both senders and receivers can influence the communicative styles of the sender, the emotions that both senders and receivers feel or attribute to their interlocutor, and the reactions of the receivers. In Study 1, couples of participants played a bogus computer game, ostensibly to test their abilities. Subsequently, “the spokesperson” was given the task to communicate to the “the receiver” a bogus low score of the other and a high score of oneself. Finally, all participants completed an adult Attachment Style Questionnaire (ASQ). A content analysis of the verbal messages of the spokespersons showed two main communication styles: frankness and mitigation. The results suggest that the spokespersons’ attachment style influences these communication styles. Using a similar procedure, Study 2 showed that spokespersons with a high avoidant attachment more frequently used frankness when communicating low scores to the receivers. Furthermore, the emotions and impressions reported by anxious and avoidant spokespersons and receivers, respectively, confirm the negative model of the self or the other, typical, respectively, in anxious and avoidant attachment. The detection of communicative strategies stemming from different attachment styles might be of use in user modeling and the planning of personalized systems
Critical Line in Random Threshold Networks with Inhomogeneous Thresholds
We calculate analytically the critical connectivity of Random Threshold
Networks (RTN) for homogeneous and inhomogeneous thresholds, and confirm the
results by numerical simulations. We find a super-linear increase of with
the (average) absolute threshold , which approaches for large , and show that this asymptotic scaling is
universal for RTN with Poissonian distributed connectivity and threshold
distributions with a variance that grows slower than . Interestingly, we
find that inhomogeneous distribution of thresholds leads to increased
propagation of perturbations for sparsely connected networks, while for densely
connected networks damage is reduced; the cross-over point yields a novel,
characteristic connectivity , that has no counterpart in Boolean networks.
Last, local correlations between node thresholds and in-degree are introduced.
Here, numerical simulations show that even weak (anti-)correlations can lead to
a transition from ordered to chaotic dynamics, and vice versa. It is shown that
the naive mean-field assumption typical for the annealed approximation leads to
false predictions in this case, since correlations between thresholds and
out-degree that emerge as a side-effect strongly modify damage propagation
behavior.Comment: 18 figures, 17 pages revte
CAOS spectroscopy of Am stars Kepler targets
The {\it Kepler} space mission and its {\it K2} extension provide photometric
time series data with unprecedented accuracy. These data challenge our current
understanding of the metallic-lined A stars (Am stars) for what concerns the
onset of pulsations in their atmospheres. It turns out that the predictions of
current diffusion models do not agree with observations. To understand this
discrepancy, it is of crucial importance to obtain ground-based spectroscopic
observations of Am stars in the {\it Kepler} and {\it K2} fields in order to
determine the best estimates of the stellar parameters.
In this paper, we present a detailed analysis of high-resolution
spectroscopic data for seven stars previously classified as Am stars. We
determine the effective temperatures, surface gravities, projected rotational
velocities, microturbulent velocities and chemical abundances of these stars
using spectral synthesis. These spectra were obtained with {\it CAOS}, a new
instrument recently installed at the observing station of the Catania
Astrophysical Observatory on Mt. Etna. Three stars have already been observed
during quarters Q0-Q17, namely: HD\,180347, HD\,181206, and HD\,185658, while
HD\,43509 was already observed during {\it K2} C0 campaign.
We confirm that HD\,43509 and HD\,180347 are Am stars, while HD 52403,
HD\,50766, HD\,58246, HD\,181206 and HD\,185658 are marginal Am stars. By means
of non-LTE analysis, we derived oxygen abundances from O{\sc
I}7771--5{\AA} triplet and we also discussed the results obtained with
both non-LTE and LTE approaches.Comment: accepted in MNRAS main journal 13 pages, 11 figures, 3 tables. arXiv
admin note: text overlap with arXiv:1404.095
Attosecond spectroscopy reveals alignment dependent core-hole dynamics in the ICl molecule.
The removal of electrons located in the core shells of molecules creates transient states that live between a few femtoseconds to attoseconds. Owing to these short lifetimes, time-resolved studies of these states are challenging and complex molecular dynamics driven solely by electronic correlation are difficult to observe. Here, we obtain few-femtosecond core-excited state lifetimes of iodine monochloride by using attosecond transient absorption on iodine 4d-16p transitions around 55 eV. Core-level ligand field splitting allows direct access of excited states aligned along and perpendicular to the ICl molecular axis. Lifetimes of 3.5 ± 0.4 fs and 4.3 ± 0.4 fs are obtained for core-hole states parallel to the bond and 6.5 ± 0.6 fs and 6.9 ± 0.6 fs for perpendicular states, while nuclear motion is essentially frozen on this timescale. Theory shows that the dramatic decrease of lifetime for core-vacancies parallel to the covalent bond is a manifestation of non-local interactions with the neighboring Cl atom of ICl
Dispelling the myth of robotic efficiency: why human space exploration will tell us more about the Solar System than will robotic exploration alone
There is a widely held view in the astronomical community that unmanned
robotic space vehicles are, and will always be, more efficient explorers of
planetary surfaces than astronauts (e.g. Coates, 2001; Clements 2009; Rees
2011). Partly this is due to a common assumption that robotic exploration is
cheaper than human exploration (although, as we shall see, this isn't
necessarily true if like is compared with like), and partly from the
expectation that continued developments in technology will relentlessly
increase the capability, and reduce the size and cost, of robotic missions to
the point that human exploration will not be able to compete. I will argue
below that the experience of human exploration during the Apollo missions, more
recent field analogue studies, and trends in robotic space exploration actually
all point to exactly the opposite conclusion.Comment: 12 pages; 5 figures. Published, with minor modifications, in
Astronomy and Geophysics, Vol. 53, pp. 2.22-2.26, 201
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