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Constraining multi-Higgs flavour models Ivanov, Igor ; ; et al in European Physical Journal C -- Particles & Fields (2014), 74 To study a flavour model with a non-minimal Higgs sector one must first define the symmetries of the fields; then identify what types of vacua exist and how they may break the symmetries; and finally ... [more ▼] To study a flavour model with a non-minimal Higgs sector one must first define the symmetries of the fields; then identify what types of vacua exist and how they may break the symmetries; and finally determine whether the remnant symmetries are compatible with the experimental data. Here we address all these issues in the context of flavour models with any number of Higgs doublets. We stress the importance of analysing the Higgs vacuum expectation values that are pseudo-invariant under the generators of all subgroups. It is shown that the only way of obtaining a physical CKM mixing matrix and, simultaneously, non-degenerate and non-zero quark masses is requiring the vacuum expectation values of the Higgs fields to break completely the full flavour group, except possibly for some symmetry belonging to baryon number. The application of this technique to some illustrative examples, such as the flavour groups Delta(27), A4 and S3, is also presented. [less ▲] Detailed reference viewed: 5 (0 ULg)A Flavor Kit for BSM models ; ; Vicente, Avelino in European Physical Journal C -- Particles & Fields (2014), 74(8), 2992 Detailed reference viewed: 5 (0 ULg)Evading death by vacuum ; ; Ivanov, Igor et al in European Physical Journal C -- Particles & Fields (2013), 73 In the Standard Model, the Higgs potential allows only one minimum at tree level. But the open possibility that there might be two scalar doublets enriches the vacuum structure, allowing for the risk that ... [more ▼] In the Standard Model, the Higgs potential allows only one minimum at tree level. But the open possibility that there might be two scalar doublets enriches the vacuum structure, allowing for the risk that we might now be in a metastable state, which we dub the panic vacuum. Current experiments at the LHC are probing the Higgs particle predicted as a result of the spontaneous symmetry breaking. Remarkably, in the two Higgs model with a softly broken U(1) symmetry, the LHC experiments already allow to exclude many panic vacuum solutions. [less ▲] Detailed reference viewed: 11 (1 ULg)Geometrical CP violation in the N-Higgs-doublet model Ivanov, Igor ; in European Physical Journal C -- Particles & Fields (2013), 73 Geometrical CP violation is a particular type of spontaneous CP violation in which the vacuum expectation values have phases which are calculable, i.e. stable against the variation of the free parameters ... [more ▼] Geometrical CP violation is a particular type of spontaneous CP violation in which the vacuum expectation values have phases which are calculable, i.e. stable against the variation of the free parameters of the scalar potential. Although originally suggested within a specific version of the three-Higgs-doublet model, it is a generic phenomenon. We investigate its viability and characteristic features in models with several Higgs doublets. Our work contains both general results and illustrative examples. [less ▲] Detailed reference viewed: 19 (0 ULg)Classification of finite reparametrization symmetry groups in the three-Higgs-doublet model Ivanov, Igor ; in European Physical Journal C -- Particles & Fields (2013), 73 Symmetries play a crucial role in electroweak symmetry breaking models with non-minimal Higgs content. Within each class of these models, it is desirable to know which symmetry groups can be implemented ... [more ▼] Symmetries play a crucial role in electroweak symmetry breaking models with non-minimal Higgs content. Within each class of these models, it is desirable to know which symmetry groups can be implemented via the scalar sector. In N-Higgs-doublet models, this classification problem was solved only for N=2 doublets. Very recently, we suggested a method to classify all realizable finite symmetry groups of Higgs-family transformations in the three-Higgs-doublet model (3HDM). Here, we present this classification in all detail together with an introduction to the theory of solvable groups, which play the key role in our derivation. We also consider generalized-CP symmetries, and discuss the interplay between Higgs-family symmetries and CP-conservation. In particular, we prove that presence of the $Z_4$ symmetry guarantees the explicit CP-conservation of the potential. This work completes classification of finite reparametrization symmetry groups in 3HDM. [less ▲] Detailed reference viewed: 17 (0 ULg)Central exclusive production of dijets at hadronic colliders Cudell, Jean-René ; Dechambre, Alice ; et al in European Physical Journal C -- Particles & Fields (2009), 61(3), 369 In view of the recent diffractive dijet data from CDF run II, we critically re-evaluate the standard approach to the calculation of central production of dijets in quasi-elastic hadronic collisions. We ... [more ▼] In view of the recent diffractive dijet data from CDF run II, we critically re-evaluate the standard approach to the calculation of central production of dijets in quasi-elastic hadronic collisions. We find that the process is dominated by the non-perturbative region, and that even perturbative ingredients, such as the Sudakov form factor, are not under theoretical control. Comparison with data allows us to fix some of the uncertainties. Although we focus on dijets, our arguments apply to other high-mass central systems, such as the Higgs boson. [less ▲] Detailed reference viewed: 51 (13 ULg)Corrections to the generalized vector dominance due to diffractive ρ3 production Ivanov, Igor ; in European Physical Journal C -- Particles & Fields (2008), 53 The idea of the vector dominance is still in use in various analyses of the experimental data of photon–hadron reactions. It makes sense, therefore, to recast results of microscopic calculations of such ... [more ▼] The idea of the vector dominance is still in use in various analyses of the experimental data of photon–hadron reactions. It makes sense, therefore, to recast results of microscopic calculations of such reactions in this language. Here we present the diffractive DIS ρ3 production as a specific correction to generalized vector dominance. We perform a coupled channel analysis of spin–orbital excitations in diffractive photoproduction and reiterate the point that ρ3 in diffractive DIS will be sensitive to a novel aspect of diffraction. [less ▲] Detailed reference viewed: 8 (0 ULg)Collider aspects of flavor physics at high Q ; ; et al in European Physical Journal C -- Particles & Fields (2008), 57(1-2), 183-307 This chapter of the 'Flavor in the era of LHC' workshop report discusses flavor-related issues in the production and decays of heavy states at the LHC at high momentum transfer Q, both from the ... [more ▼] This chapter of the 'Flavor in the era of LHC' workshop report discusses flavor-related issues in the production and decays of heavy states at the LHC at high momentum transfer Q, both from the experimental and the theoretical perspective. We review top quark physics, and discuss the flavor aspects of several extensions of the standard model, such as supersymmetry, little Higgs models or models with extra dimensions. This includes discovery aspects, as well as the measurement of several properties of these heavy states. We also present publicly available computational tools related to this topic. © Springer-Verlag / Società Italiana di Fisica 2008. [less ▲] Detailed reference viewed: 19 (11 ULg) |
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