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Interactions fondamentales, Astroparticules et Cosmologie
(5) Production(s) de l'année 2022


The hMSSM with a Light Gaugino/Higgsino Sector:Implications for Collider and Astroparticle Physics
Auteur(s): Arcadi Giorgio, Djouadi Abdelhak, He HongJian, Kneur J.L., Xiao RuiQing
(Document sans référence bibliographique) Texte intégral en Openaccess :
Ref HAL: hal03713127_v1
Ref Arxiv: 2206.11881
Ref INSPIRE: 2100088
Ref. & Cit.: NASA ADS
Exporter : BibTex  endNote
Résumé: The hMSSM is a special parameterization of the minimal supersymmetric extension of the Standard Model (MSSM) in which the mass of the lightest Higgs boson is automatically set to the LHC measured value, $M_h\!\!=\!\! 125$ GeV, by adjusting the supersymmetric particle spectrum such that it provides the required amount of radiative corrections to the Higgs boson masses. The latter spectrum was in general assumed to be very heavy, as indicated by the present exclusion limits of the LHC, not to affect the phenomenology of the Higgs sector. In this work, we investigate the impact on the hMSSM by a light gaugino and higgsino sector, that is allowed by the present LHC data. In particular, we discuss the radiative corrections due to charginos and neutralinos to the Higgs boson masses and couplings and show that an hMSSM can still be realized in this context. We first describe how this scenario is implemented in the package SuSpect that generates the MSSM Higgs and supersymmetric spectra. We then analyze the possible impact of Higgs boson decays into these new states, as well as the reverse cascade channels with Higgs bosons in the final states, for the constraints on the MSSM Higgs sector at the LHC. We further explore the cosmological constraints on the hMSSM with a light gauginohiggsino spectrum. We analyze the relic abundance of the lightest neutralino as a candidate of the dark matter in the Universe and the constraints on its mass and couplings by the present and future astroparticle physics experiments.



Holographic models of composite Higgs in the Veneziano limit. Part II. Fermionic sector
Auteur(s): Elander D., Frigerio M., Knecht Marc, Kneur J.L.
(Article) Publié:
Jhep, vol. 05 p.066 (2022)
Texte intégral en Openaccess :
Ref HAL: hal03520952_v1
Ref Arxiv: 2112.14740
Ref INSPIRE: 1998692
DOI: 10.1007/JHEP05(2022)066
Ref. & Cit.: NASA ADS
Exporter : BibTex  endNote
Résumé: We continue our study of stronglycoupled, approximately scaleinvariant gauge theories with a large number of flavours, which provide a suitable ultraviolet completion of the compositeHiggs scenario. We identify the requisite operators to realise partial compositeness of the StandardModel fermions. In order to compute the spectrum of composite fermionic states, we extend the bottomup holographic models, which we previously introduced to capture the main features of the nonperturbative dynamics in the Veneziano limit, by adding fermion fields in the bulk. We identify regions in parameter space where some fermionic bound states become light, depending in particular on the number of flavours, the operator scaling dimensions, and the bulk Yukawa couplings. We also observe a dense spectrum of states, when multiscale dynamics is induced by a large backreaction of bulk scalars on the geometry. Adapting the formalism of the holographic Wilsonian renormalisation group, we study the linear coupling between the composite and elementary fermions, as a function of energy scale. We find that, in some circumstances, the associated operators are dangerously irrelevant: the renormalisationgroup flow gives rise to a large linear coupling in the infrared, even when it is irrelevant from the point of view of the ultraviolet fixed point. We finally compute the partially composite spectrum, correlate it with the analysis of the flow, and assess the potential phenomenological implications, e.g. for the topquark partners.



The Higgs Boson Mass as Fundamental Parameter of the Minimal Supersymmetric Standard Model
Auteur(s): ElKosseifi Rima, Kneur J.L., Moultaka G., Zerwas Dirk
(Document sans référence bibliographique) Texte intégral en Openaccess :
Ref HAL: hal03574108_v1
Ref Arxiv: 2202.06919
Ref INSPIRE: 2032066
Ref. & Cit.: NASA ADS
Exporter : BibTex  endNote
Résumé: In the Minimal Supersymmetric Standard Model (MSSM) the mass of the lightest neutral Higgs boson is determined by the supersymmetric parameters. In the $m_h$MSSM the precisely measured Higgs boson replaces the trilinear coupling $A_t$ as input parameter. Expressions are derived to extract $A_t$ in a semianalytical form as a function of the light Higgs boson (pole) mass. An algorithm is developed and implemented at twoloop precision, generalizable to higher orders, to perform this inversion consistently. The result of the algorithm, implemented in the SuSpect spectrum calculator, is illustrated on a parameter set compatible with LHC measurements.
Commentaires: 32 pages, 4 figures, 4 tables



Effective comparison of neutrinomass models
Auteur(s): Coy R., Frigerio M.
(Article) Publié:
Physical Review D, vol. 105 p.115041 (2022)
Texte intégral en Openaccess :
Ref HAL: hal03410948_v1
Ref Arxiv: 2110.09126
DOI: 10.1103/PhysRevD.105.115041
WoS: WOS:000822568800005
Ref. & Cit.: NASA ADS
Exporter : BibTex  endNote
Résumé: New physics in the lepton sector may account for neutrino masses, affect electroweak precision observables, induce chargedlepton flavour violation, and shift dipole moments. The lowenergy predictions of different models are most conveniently compared within the formalism of effective field theory. To illustrate the benefits of this approach, we derive the Wilson coefficients for a set of representative models: the fermionic seesaw mechanisms (type I and III), the Zee model, and a minimal leptoquark model. In each case, the Weinberg and the dipole operators have qualitatively different origins. In parallel, we present the modelindependent constraints on the Wilson coefficients coming from various lepton observables. We then show that it becomes straightforward to understand the allowed parameter space for each model, and to discriminate between them. The Zee and leptoquark models are suitable to address the muon g − 2 anomaly.We also confront the models with the anomalies in the Wboson mass and semileptonic Bmeson decays.



Towards topdown holographic composite Higgs: minimal coset from maximal supergravity
Auteur(s): Elander D., Piai Maurizio
(Article) Publié:
Journal Of High Energy Physics, vol. 03 p.049 (2022)
Texte intégral en Openaccess :
Ref HAL: hal03380561_v1
Ref Arxiv: 2110.02945
Ref INSPIRE: 1939288
DOI: 10.1007/JHEP03(2022)049
Ref. & Cit.: NASA ADS
Exporter : BibTex  endNote
Résumé: Within the context of topdown holography, we study a oneparameter family of regular background solutions of maximal gauged supergravity in seven dimensions, dimensionally reduced on a 2torus. The dual, fourdimensional confining field theory realises the global (spontaneous as well as explicit) symmetry breaking pattern SO(5) → SO(4). We compute the complete mass spectrum for the fluctuations of the 128 bosonic degrees of freedom of the fivedimensional gravity theory, which correspond to scalar, pseudoscalar, vector, axialvector, and tensor bound states of the dual field theory, and includes particles with exotic SO(4) quantum numbers. We confirm the existence of tachyonic instabilities near the boundaries of the parameter space.We discuss the interplay between explicit and spontaneous symmetry breaking. The SO(5)/SO(4) coset might provide a first step towards the realisation of a calculable framework and ultraviolet completion of minimal composite Higgs models, if the four pseudoNambuGoldstone bosons are identified with the real components of the Higgs doublet in the standard model (SM), and a subgroup of SO(4) with the SU(2) × U(1) SM gauge group. We exhibit an example with an additional localised boundary term that mimics the effect of a weaklycoupled external sector.
