Faculte des science et Techniques

Nouakchott, Mauritania

Faculte des science et Techniques

Nouakchott, Mauritania
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Michard A.,Paris West University Nanterre La Défense | Ibouh H.,Faculte des science et Techniques | Charriere A.,26 rue J. P. Chabrol
Terra Nova | Year: 2011

We question for the first time the origin of enigmatic structures, herein termed syncline-topped anticlinal ridges (STARs). In the Central High Atlas (CHA) of Morocco, small synclines of Upper Palaeocene-? Eocene deposits are only preserved on top of Triassic-Jurassic anticlinal ridges. We explain these peculiar structures through a three-step evolution: (i) early halokinetic evolution leading to the formation of elongated diapiric ridges over basement faults, ending with magmatic intrusions and enhanced diapiric ascent up to the surface; (ii) Palaeocene-? Eocene unconformable sedimentation; (iii) Late Eocene-Quaternary shortening phases, which resulted in the erosion of the Palaeocene-? Early Eocene deposits, except in the breached anticlinal axes. The comparison with the breached valley ("makhteshim") of the Syrian Arc in the Negev Desert allows us to emphasize the role of the early diapiric evolution of the CHA domain in the genesis of the STAR structure. © 2011 Blackwell Publishing Ltd.

Arhrib A.,Faculte des science et Techniques | Arhrib A.,Cadi Ayyad University | Benbrik R.,Cadi Ayyad University | Benbrik R.,Institute Fisica Of Cantabria Csic Uc | And 3 more authors.
Journal of High Energy Physics | Year: 2012

We study the two photon decay channel of the Standard Model-like component of the CP-even Higgs bosons present in the type II Seesaw Model. The corresponding cross-section is found to be significantly enhanced in parts of the parameter space, due to the (doubly-)charged Higgs bosons' (H ±±)H ± virtual contributions, while all the other Higgs decay channels remain Standard Model(SM)-like. In other parts of the parameter space H ±± (and H ±) interfere destructively, reducing the two photon branching ratio tremendously below the SM prediction. Such properties allow to account for any excess such as the one reported by ATLAS/CMS at ≈ 125 GeV if confirmed by future data; if not, for the fact that a SM-like Higgs exclusion in the diphoton channel around 114-115 GeV as reported by ATLAS, does not contradict a SM-like Higgs at LEP(!), and at any rate, for the fact that ATLAS/CMS exclusion limits put stringent lower bounds on the H ±± mass, particularly in the parameter space regions where the direct limits from same-sign leptonic decays of H ±± do not apply. © SISSA 2012.

Kaouadji M.,Faculte des science et Techniques | Bennini B.,Laboratoire Of Pharmacognosie Et Of Phytochimie | Chulia A.J.,Laboratoire Of Pharmacognosie Et Of Phytochimie
Tetrahedron Letters | Year: 2012

Continuation of the phytochemical analysis of Erica cinerea fresh aerial parts resulted in the isolation of two new compounds with a very close chromatographic behavior. On the basis of spectroscopic evidence (UV, MS and NMR), the structures were established as (-)-(3S,6E)-1,9-bis(p-hydroxyphenyl)-3- hydroxynon-6-en-5-one 3-O-β-d-glucoside named 6,7-anhydroericaone 3-O-β-d-glucoside and (-)-(3S)-1,9-bis(p-hydroxyphenyl)-3-hydroxynonan-5,6- dione 3-O-β-d-glucoside named α-ericadione 3-O-β-d-glucoside. Unanticipated by its α-alkadione type structure - a very unusual feature in the plant kingdom - the latter metabolite was found as a mixture of the minor s-cis and the major s-trans conformers. Moreover, the GC-MS analysis of the aglycone moieties of such glucosides, pointed out the permanent absence of the molecular ion and the constant hydroxybenzylium base peak, as well as the conversion of the α-dione into the major α-keto-enol tautomer. © 2012 Published by Elsevier Ltd.

Arhrib A.,Faculte des science et Techniques | Ferreira P.M.,Polytechnic Institute of Lisbon | Ferreira P.M.,University of Lisbon | Santos R.,Polytechnic Institute of Lisbon | Santos R.,University of Lisbon
Journal of High Energy Physics | Year: 2014

The Higgs boson recently discovered at the Large Hadron Collider has shown to have couplings to the remaining particles well within what is predicted by the Standard Model. The search for other new heavy scalar states has so far revealed to be fruitless, imposing constraints on the existence of new scalar particles. However, it is still possible that any existing heavy scalars would preferentially decay to final states involving the light Higgs boson thus evading the current LHC bounds on heavy scalar states. Moreover, decays of the heavy scalars could increase the number of light Higgs bosons being produced. Since the number of light Higgs bosons decaying to Standard Model particles is within the predicted range, this could mean that part of the light Higgs bosons could have their origin in heavy scalar decays. This situation would occur if the light Higgs couplings to Standard Model particles were reduced by a concomitant amount. Using a very simple extension of the SM - the two-Higgs doublet model - we show that in fact we could already be observing the effect of the heavy scalar states even if all results related to the Higgs are in excellent agreement with the Standard Model predictions. © 2014 The Author(s).

El Baghdadi M.,Faculte des science et Techniques | El Baghdadi M.,CNRS Georesources lab | Barakat A.,CNRS Georesources lab | Sajieddine M.,Sultan Moulay Slimane University | Nadem S.,CNRS Georesources lab
Environmental Earth Sciences | Year: 2012

The assessment of anthropogenic impact in the urban environment can be evaluated according to heavy metal contents of soils such as Pb, Cu, Zn, Cd and Fe. These elements have more affinity to establish metallic bond with ferrous material leading to enhancement of soil magnetic susceptibility. The objective of this study was to undertake joint magnetic and geochemical investigations of road-side urban soil materials to address the environmental pollution of Beni Mellal city that has been subjected to environmental stress, due to population overpressure and related urbanization. Twenty three soils magnetic susceptibility profiles were made along 5 km peripheral national road (N8) in Beni Mellal. The magnetic survey reported here for the first time on this City's topsoils tries to establish the link between magnetic properties and the content of heavy metals. High magnetic susceptibility values and high contents of heavy metals were found near the paved edge of the road and within the place reserved as large engine park. Magnetic extracts of highly polluted areas and unpolluted soil (olive plantation) were analyzed by SEM coupled with RDX in order to discriminate anthropogenic magnetic spherules and pedo-lithogenic magnetite-like minerals. Magnetic mineralogy determined by Mössbauer spectroscopy suggests the presence of hematite, magnetite and goethite in highly polluted areas. The iron oxides and especially goethite are efficient in incorporating and/or adsorbing foreign ions. © 2011 Springer-Verlag.

Douda S.,Faculte des science et Techniques | Bagri A.,ENIC | El Imrani A.A.,Mohammed V University
Electronic Letters on Computer Vision and Image Analysis | Year: 2011

Fractal image compression is time consuming due to the search of the matching between range and domain blocks. In order to improve this compression method, we propose firstly, a fast method for reducing the computational complexity of fractal encoding by reducing the size of the domain pool. This reduction is based on the lowest horizontal and vertical DCT coefficients of domain blocks. The experimental results on the test images show that the proposed method reduces the time computation and reaches a high speedup factor without decreasing the image quality. Secondly, we combine our method to the AP2D approach which uses two domain pools in two steps of encoding. A more reduction of encoding time is obtained without decreasing the image quality.

Arhrib A.,Faculte des science et Techniques | Arhrib A.,National Cheng Kung University | Arhrib A.,Cadi Ayyad University | Chiang C.-W.,National Central University | And 5 more authors.
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2012

We study the implications of the searches based on H→τ +τ - by the ATLAS and CMS collaborations on the parameter space of the two-Higgs-doublet model (2HDM). In the 2HDM, the scalars can decay into a tau pair with a branching ratio larger than the SM one, leading to constraints on the 2HDM parameter space. We show that in model II, values of tanβ>1.8 are definitively excluded if the pseudoscalar is in the mass range 110GeV

Arhrib A.,Faculte des science et Techniques | Arhrib A.,Cadi Ayyad University | Benbrik R.,Cadi Ayyad University | Benbrik R.,Institute Fisica Of Cantabria Csic Uc | Gaur N.,University of Delhi
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2012

Motivated by the recent results from LHC on the di-photon search for a standard model (SM) Higgs-like boson, in this work we discuss the implications of this signal in the framework of the inert Higgs doublet model. Our analysis takes account of the previous limits from Higgs searches at LEP, the Tevatron, and the LHC. We have also considered the bounds coming from perturbativity, unitarity, vacuum stability, and electroweak precision tests. We show that the charged Higgs contributions can interfere constructively or destructively with the W gauge bosons' loops leading to enhancement or suppression of the di-photon rate with respect to the SM rate. We show also that the invisible decay of the Higgs, if open, could affect the total width of the SM Higgs boson and therefore suppress the di-photon rate. © 2012 American Physical Society.

Arnaud E.,Faculte des science et Techniques | Chantalat R.,CISTEME | Monediere T.,Faculte des science et Techniques | Rodes E.,Faculte des science et Techniques | Thevenot M.,Faculte des science et Techniques
IEEE Antennas and Wireless Propagation Letters | Year: 2010

This letter presents an original solution to solve the matching problem of the circularly self-polarizing electromagnetic band-gap (EBG) antennas. More precisely, a comprehensive method to design a self-polarizing EBG antenna will be detailed. This kind of antenna had been designed before, but it was very poorly matched. An iris-based matching system has been used here, which produced a satisfying return loss while deteriorating the axial ratio (AR). An original device will be introduced, which allowed us to compensate for this degradation. Finally, to validate this new structure, a 20-dBi antenna working around 9 GHz and showing an AR lower than 1 dB over a 100-MHz bandwidth has been conceived, realized, and successfully measured. © 2006 IEEE.

Arhrib A.,Faculte des science et Techniques | Arhrib A.,Cadi Ayyad University | Benbrik R.,Cadi Ayyad University | Benbrik R.,Institute Fisica Of Cantabria Csic Uc | And 6 more authors.
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2011

The standard model Higgs sector, extended by one weak gauge triplet of scalar fields with a very small vacuum expectation value, is a very promising setting to account for neutrino masses through the so-called type II seesaw mechanism. In this paper we consider the general renormalizable doublet/triplet Higgs potential of this model. We perform a detailed study of its main dynamical features that depend on five dimensionless couplings and two mass parameters after spontaneous symmetry breaking, and highlight the implications for the Higgs phenomenology. In particular, we determine (i) the complete set of tree-level unitarity constraints on the couplings of the potential and (ii) the exact tree-level boundedness from below constraints on these couplings, valid for all directions. When combined, these constraints delineate precisely the theoretically allowed parameter space domain within our perturbative approximation. Among the seven physical Higgs states of this model, the mass of the lighter (heavier) CPeven state h0 (H0) will always satisfy a theoretical upper (lower) bound that is reached for a critical value μc of μ (the mass parameter controlling triple couplings among the doublet/triplet Higgses). Saturating the unitarity bounds, we find an upper bound mh0

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