Results 11 to 20 of about 1,453 (168)
Alternative framework for the left-right symmetric model including vector-like fermions
Journal of High Energy PhysicsWe extend the left-right symmetric model with an additional non-abelian SU (2) gauge symmetry. The particle content is augmented by one generation of vector-like fermions transforming under the fundamental representation of this new gauge group ...
Yassine Bouzeraib, Mohamed Sadek Zidi
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Baryogenesis and dark matter with vector-like fermions [PDF]
Journal of High Energy Physics, 2013 We show that vector-like fermions can act as the dark matter candidate in the universe whilst also playing a crucial role in electroweak baryogenesis through contributing to the barrier in the one-loop thermal scalar potential. In order for the new fermions to give rise to a strong first order phase transition, we show that one requires rather large ...
Fairbairn, M., Grothaus, P.
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Electroweak precision constraints on vector-like fermions [PDF]
The European Physical Journal C, 2008 We calculate the oblique electroweak corrections and confront with the experiments in an extension of the Standard Model. The new fields added are a vector-like weak doublet and a singlet fermion. After electroweak symmetry breaking there is a mixing between the components of the new fields, but no mixing allowed with the standard fermions.
Cynolter, G, Lendvai, E
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Vector-like fermion contributions to ε′ [PDF]
Nuclear Physics B, 1986 We consider extensions to the standard electroweak model which contain new vector-like fermions at the Fermi scale as a source of CP violation. After a detailed calculation of the QCD corrections to leading order, we find that the new contributions to |e′/e| range typically from 10 −3 to 10 −2 when we require that the corresponding contributions to
F. Del Aguila, M.K. Chase, J. Cortes
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Parity realization in vector-like theories from fermion bilinears [PDF]
Journal of High Energy Physics, 2008 We reconsider in this paper the old aim of trying to understand if the observed realization of discrete symmetries as Parity or CP in the QCD vacuum can be satisfied from first principles. We show how under the appropriate assumptions implicitely done by Vafa and Witten in their old paper on parity realization in vector-like theories, all parity and CP
Azcoiti, V., di Carlo, G., Vaquero, A.
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Wilson coefficients and natural zeros from the on-shell viewpoint
Journal of High Energy Physics, 2022 We show how to simplify the calculation of the finite contributions from heavy particles to EFT Wilson coefficients by using on-shell methods. We apply the technique to the one-loop calculation of g − 2 and Hγγ, showing how finite contributions can be ...
Luigi Delle Rose +2 more
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SU(5) × U(1)′ Models with a Vector-like Fermion Family [PDF]
Universe, 2021 Motivated by experimental measurements indicating deviations from the Standard Model predictions, we discuss F-theory-inspired models, which, in addition to the three chiral generations, contain a vector-like complete fermion family. The analysis takes place in the context of SU(5)×U(1)′ GUT embedded in an E8 covering group, which is associated with ...
A. Karozas +2 more
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Current status on pair-produced muon-philic vectorlike leptons in multilepton channels at the LHC
Journal of High Energy Physics, 2023 In this work, we obtain the current limits on the pair production of vectorlike leptons decaying to a Standard Model gauge boson and a lepton in the second generation using the Run-2 data at the LHC.
Junichiro Kawamura, Seodong Shin
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The two scales of new physics in Higgs couplings
Journal of High Energy Physics, 2023 Higgs coupling deviations from Standard Model predictions contain information about two scales of Nature: that of new physics responsible for the deviation, and the scale where new bosons must appear. The two can coincide, but they do not have to.
Raffaele Tito D’Agnolo +3 more
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Higgs vacuum stability with vectorlike fermions [PDF]
Physical Review D, 2019 We present the effects of vector-like fermions (VLF) on the stability of the Higgs electroweak vacuum, using the renormalization group improved Higgs effective potential. We review the calculation of the one-loop beta-functions of the standard model couplings, paying particular attention to the fermion contributions.
Gopalakrishna, Shrihari +1 more
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