| 1. |
- Belyaev, Alexander, et al.
(författare)
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Di-boson signatures as standard candles for partial compositeness
- 2017
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Ingår i: Journal of High Energy Physics. - 1029-8479 .- 1126-6708. ; 2017:1
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Tidskriftsartikel (refereegranskat)abstract
- Composite Higgs Models are often constructed including fermionic top partners with a mass around the TeV scale, with the top partners playing the role of stabilizing the Higgs potential and enforcing partial compositeness for the top quark. A class of models of this kind can be formulated in terms of fermionic strongly coupled gauge theories. A common feature they all share is the presence of specific additional scalar resonances, namely two neutral singlets and a colored octet, described by a simple effective Lagrangian. We study the phenomenology of these scalars, both in a model independent and model dependent way, including the bounds from all the available searches in the relevant channels with di-boson and di-top final states. We develop a generic framework which can be used to constrain any model containing pseudo-scalar singlets or octets. Using it, we find that such signatures provide strong bounds on the compositeness scale complementary to the traditional EWPT and Higgs couplings deviations. In many cases a relatively light scalar can be on the verge of discovery as a first sign of new physics.
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| 2. |
- Cacciapaglia, Giacomo, et al.
(författare)
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Light scalars in composite Higgs models
- 2019
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Ingår i: Frontiers of Physics. - : Frontiers Media SA. - 2296-424X. ; 7:12
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Tidskriftsartikel (refereegranskat)abstract
- A composite Higgs boson is likely to be accompanied by additional light states generated by the same dynamics. This expectation is substantiated when realising the composite Higgs mechanism by an underlying gauge theory. We review the dynamics of such objects, which may well be the first sign of compositeness at colliders. We also update our previous analysis of the bounds from LHC searches to the latest results, and discuss the projected reach of the High-Luminosity run.
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| 3. |
- Cacciapaglia, Giacomo, et al.
(författare)
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Revealing timid pseudo-scalars with taus at the LHC
- 2018
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Ingår i: European Physical Journal C. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 78:9
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Tidskriftsartikel (refereegranskat)abstract
- A light pseudo-scalar that is copiously produced at the LHC may still be allowed by present searches. While masses above 65 GeV are effectively covered by di-photon searches, the lower mass window can be tested by a new search for boosted di-tau resonances. We test this strategy on a set of composite Higgs models with top partial compositeness, where most models can be probed with an integrated luminosity below 300 fb−1
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| 4. |
- Ferreira, P. M., et al.
(författare)
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CP4 miracle : shaping Yukawa sector with CP symmetry of order four
- 2018
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Ingår i: Journal of High Energy Physics. - 1029-8479. ; 2018:1
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Tidskriftsartikel (refereegranskat)abstract
- We explore the phenomenology of a unique three-Higgs-doublet model based on the single CP symmetry of order 4 (CP4) without any accidental symmetries. The CP4 symmetry is imposed on the scalar potential and Yukawa interactions, strongly shaping both sectors of the model and leading to a very characteristic phenomenology. The scalar sector is analyzed in detail, and in the Yukawa sector we list all possible CP4-symmetric structures which do not run into immediate conflict with experiment, namely, do not lead to massless or mass-degenerate quarks nor to insufficient mixing or CP -violation in the CKM matrix. We show that the parameter space of the model, although very constrained by CP4, is large enough to comply with the electroweak precision data and the LHC results for the 125 GeV Higgs boson phenomenology, as well as to perfectly reproduce all fermion masses, mixing, and CP violation. Despite the presence of flavor changing neutral currents mediated by heavy Higgs scalars, we find through a parameter space scan many points which accurately reproduce the kaon CP -violating parameter ϵK as well as oscillation parameters in K and B(s) mesons. Thus, CP4 offers a novel minimalistic framework for building models with very few assumptions, sufficient predictive power, and rich phenomenology yet to be explored.
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| 5. |
- Ferretti, Gabriele, 1963, et al.
(författare)
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Beyond the Standard Model Physics at the HL-LHC and HE-LHC
- 2018
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This is the third out of five chapters of the final report [1] of the Workshop on Physics at HL-LHC, and perspectives on HE-LHC [2]. It is devoted to the study of the potential, in the search for Beyond the Standard Model (BSM) physics, of the High Luminosity (HL) phase of the LHC, defined as 3 ab−1 of data taken at a centre-of-mass energy of 14 TeV, and of a possible future upgrade, the High Energy (HE) LHC, defined as 15 ab−1 of data at a centre-of-mass energy of 27 TeV. We consider a large variety of new physics models, both in a simplified model fashion and in a more model-dependent one. A long list of contributions from the theory and experimental (ATLAS, CMS, LHCb) communities have been collected and merged together to give a complete, wide, and consistent view of future prospects for BSM physics at the considered colliders. On top of the usual standard candles, such as supersymmetric simplified models and resonances, considered for the evaluation of future collider potentials, this report contains results on dark matter and dark sectors, long lived particles, leptoquarks, sterile neutrinos, axion-like particles, heavy scalars, vector-like quarks, and more. Particular attention is placed, especially in the study of the HL-LHC prospects, to the detector upgrades, the assessment of the future systematic uncertainties, and new experimental techniques. The general conclusion is that the HL-LHC, on top of allowing to extend the present LHC mass and coupling reach by 20−50% on most new physics scenarios, will also be able to constrain, and potentially discover, new physics that is presently unconstrained. Moreover, compared to the HL-LHC, the reach in most observables will generally more than double at the HE-LHC, which may represent a good candidate future facility for a final test of TeV-scale new physics.
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| 6. |
- Meirose, Bernhard, et al.
(författare)
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Real-time accelerator diagnostic tools for the max iv storage rings
- 2020
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Ingår i: Instruments. - : MDPI AG. - 2410-390X. ; 4:3
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, beam diagnostic and monitoring tools developed by the MAX IV Operations Group are discussed. In particular, beam position monitoring and accelerator tunes visualization software tools, as well as tools that directly influence the beam quality and stability, are introduced. An availability and downtime monitoring application is also presented.
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| 7. |
- Nottensteiner, Franz, et al.
(författare)
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Classification of anomaly-free 2HDMs with a gauged U (1)′ symmetry
- 2019
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Ingår i: Physical Review D. - 2470-0010. ; 100:11
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Tidskriftsartikel (refereegranskat)abstract
- Two-Higgs-doublet models (2HDMs) with a flavored U(1)′ gauge symmetry are a popular extension to the Standard Model (SM), yet they currently lack a complete survey. In this paper, we present a full classification of anomaly-free 2HDMs within the SM fermion content, resulting in a total of 11 distinct models. Four of these are relatively well studied, while the rest either partially, or entirely, lack previous treatment. We study these textures under a variety of experimental bounds, focusing mainly on the previously unexplored models. This work is intended to act as a catalog to models worth considering in greater detail.
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| 8. |
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