DPA on quasi delay insensitive asynchronous circuits: formalization and improvement

The purpose of this paper is to formally specify a flow devoted to the design of Differential Power Analysis (DPA) resistant QDI asynchronous circuits. The paper first proposes a formal modeling of the electrical signature of QDI asynchronous circuits. The DPA is then applied to the formal model in order to identify the source of leakage of this type of circuits. Finally, a complete design flow is specified to minimize the information leakage. The relevancy and efficiency of the approach is demonstrated using the design of an AES crypto-processor.Comment: Submitted on behalf of EDAA (http://www.edaa.com/

Global fit to Higgs signal strengths and couplings and implications for extended Higgs sectors

The most recent LHC data have provided a considerable improvement in the precision with which various Higgs production and decay channels have been measured. Using all available public results from ATLAS, CMS and the Tevatron, we derive for each final state the combined confidence level contours for the signal strengths in the (gluon fusion + ttH associated production) versus (vector boson fusion + VH associated production) space. These "combined signal strength ellipses" can be used in a simple, generic way to constrain a very wide class of New Physics models in which the couplings of the Higgs boson deviate from the Standard Model prediction. Here, we use them to constrain the reduced couplings of the Higgs boson to up-quarks, down-quarks/leptons and vector boson pairs. We also consider New Physics contributions to the loop-induced gluon-gluon and photon-photon couplings of the Higgs, as well as invisible/unseen decays. Finally, we apply our fits to some simple models with an extended Higgs sector, in particular to Two-Higgs-Doublet models of Type I and Type II, the Inert Doublet model, and the Georgi-Machacek triplet Higgs model.Comment: 31 pages, 15 figures; v2: fixed important factor of 2 missing in Eq. (1) (results unchanged), extended discussion in the next-to-last paragraph of Section 3, some references added; v3: appendices and references added, matches version accepted by PR

Status of invisible Higgs decays

We analyze the extent to which the LHC and Tevatron results as of the end of 2012 constrain invisible (or undetected) decays of the Higgs boson-like state at ~ 125 GeV. To this end we perform global fits for several cases: 1) a Higgs boson with Standard Model (SM) couplings but additional invisible decay modes; 2) SM couplings to fermions and vector bosons, but allowing for additional new particles modifying the effective Higgs couplings to gluons and photons; 3) no new particles in the loops but tree-level Higgs couplings to the up-quarks, down-quarks and vector bosons, relative to the SM, treated as free parameters. We find that in the three cases invisible decay rates of 23%, 61%, 88%, respectively, are consistent with current data at 95% confidence level (CL). Limiting the coupling to vector bosons, CV, to CV < 1 in case 3) reduces the allowed invisible branching ratio to 56% at 95% CL. Requiring in addition that the Higgs couplings to quarks have the same sign as in the SM, an invisible rate of up to 36% is allowed at 95% CL. We also discuss direct probes of invisible Higgs decays, as well as the interplay with dark matter searches.Comment: 14 pages, 8 figures; v2: extended discussion on ZH associated production, references added, minor corrections; v4: matches final version published in Phys. Lett.

Higgs Couplings at the End of 2012

Performing a fit to all publicly available data, we analyze the extent to which the latest results from the LHC and Tevatron constrain the couplings of the Higgs boson-like state at ~ 125 GeV. To this end we assume that only Standard Model (SM) particles appear in the Higgs decays, but tree-level Higgs couplings to the up-quarks, down-quarks and vector bosons, relative to the SM are free parameters. We also assume that the leptonic couplings relative to the SM are the same as for the down-quark, and a custodial symmetry for the V=W,Z couplings. In the simplest approach, the effective Higgs couplings to gluons and photons are computed in terms of the previous parameters. This approach is also applied to Two-Higgs-Doublet Models of Type I and Type II. However, we also explore the possibility that the net Higgs to gluon-gluon and gamma-gamma couplings have extra loop contributions coming from Beyond-the-Standard Model physics. We find that the SM p-value ~ 0.5 is more than 2 sigma away from fits in which: a) there is some non-SM contribution to the gamma-gamma coupling of the Higgs; or b) the sign of the top quark coupling to the Higgs is opposite that of the W coupling. In both these cases p-values ~ 0.9 can be achieved. Since option b) is difficult to realize in realistic models, it would seem that new physics contributions to the effective couplings of the Higgs are preferred.Comment: 25 pages, 11 figures; v2: minor corrections, references added; v3: acknowledgement adde

Evaluation de la sécurité du trafic par microsimulation

Actuellement, les analyses de sécurité des réseaux routiers sont essentiellement « réactives », s’efforçant de localiser des points noirs à partir de relevés d’accidents. La présente étude propose de mener des analyses de sécurité « actives » en déterminant un indicateur de sécurité issu de la microsimulation des flux de circulation. Limitée à la problématique des accidents en file, la présente recherche propose un nouvel indicateur de sécurité : la densité d’insécurité UD (pour Unsafety Density). Dans la microsimulation, des modèles de comportement gouvernent la progression des véhicules, en interdisant toute collision. Le paramètre UD proposé se base sur le concept d’une hypothétique collision survenant entre deux véhicules se suivant, en prenant en compte aussi bien la probabilité que la gravité de l’accident. Une étude de cas sur une portion autoroutière fournit des résultats encourageants, démontrant les potentialités de la microsimulation pour l’évaluation de la sécurité routière. Des zones présentant une dangerosité plus importante que le reste du réseau peuvent ainsi être localisées en fonction des conditions de trafic. En complément aux indicateurs classiques de performance, la densité d’insécurité permet une analyse globale, fournissant une aide précieuse lors de la gestion, mais aussi de la conception de réseaux routiers

Géométrie tridimensionnelle des voies de circulation

L’étude des projets routiers se déroule depuis toujours selon un découpage parfaitement défini qui donne lieu à l’étude successive des trois aspects du tracé que sont le plan de situation, le profil en long et le profil en travers. Pris indépendamment, ces trois espaces-plans étroitement liés sont faciles d’accès. Le problème devient plus ardu si on les traite simultanément. Pourtant, une vision globale en trois dimensions est nécessaire pour certains paramètres comme la visibilité, la lisibilité ou l’intégration dans le site, caractéristiques fondamentales dont dépendront la sécurité, la viabilité et la qualité d’une route. La maîtrise de ces questions d’interaction d’espaces-plans est donc indispensable. L’avènement et le développement des logiciels de conception assistée par ordinateur (CAO) ont permis de répondre en partie aux besoins de traitement tridimensionnel, notamment au niveau de la visualisation des projets, formidable outil de communication avec les professionnels et le public. Néanmoins des lacunes subsistent. La présente étude permet la prospection et l’étude théorique de méthodes et principes de base permettant une meilleure maîtrise spatiale du tracé. Sans révolutionner totalement la conception routière, elle apporte un « cahier des charges » pour les logiciels routiers de CAO permettant de mieux appréhender la conception, mais aussi le contrôle des voies de circulation, par exemple lors d’audits de sécurité

On the presentation of the LHC Higgs Results

We put forth conclusions and suggestions regarding the presentation of the LHC Higgs results that may help to maximize their impact and their utility to the whole High Energy Physics community.Comment: Conclusions from the workshops "Likelihoods for the LHC Searches", 21-23 January 2013 at CERN, "Implications of the 125 GeV Higgs Boson", 18-22 March 2013 at LPSC Grenoble, and from the 2013 Les Houches "Physics at TeV Colliders" workshop. 16 pages, 3 figures. Version 2: Comment added on the first publication of signal strength likelihoods in digital form by ATLA

Chemical and dynamical processes in the mesospheric emissive layer. First results of stereoscopic observations

[1] The mesospheric emissive layer is an efficient tracer of the dynamical processes propagating in the atmosphere at that level. CCD images in the near infrared taken from the ground at slant angles often reveal the existence of wavy fields. A series of such images has been transformed, using matrix operations, producing a downward satellite-type view that covers a circular area of radius ∼1000 km at the altitude of the layer. The Fourier characteristics of the wave system are measured using a Morlet-type wavelet generator function with horizontal wavelengths of mostly ∼20–40 km and 100–150 km and temporal periods of ∼15–30 min. An oxygen-hydrogen model is used to evaluate the response of the emissive layer to a progressive density wave. The altitude of the layer is modulated with an amplitude of ∼0.8–1.8 km when a density wave propagates vertically. The layer thickness is slightly modulated and is equal to ∼7 km. Stereoscopic pairs of photographs taken simultaneously on 8–9 September 2000 at the Château-Renard and Pic du Midi observatories are used to obtain surface maps of the emission layer barycenter altitude. A stereocorrelation method suitable for low contrast objects without discrete contours is employed. Preliminary results for areas ∼50 × 50 km2 are presented. The surface maps of the layer barycenter altitude depict the existence of waves. They show the same wavy structure and compare favorably with the maps showing the emission intensity