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1.
Phys Rev Lett ; 129(22): 221801, 2022 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-36493433

RESUMO

We show that any new interaction resulting in a chirally enhanced contribution to the muon magnetic moment necessarily modifies the decay rate of the Higgs boson to muon pairs or generates the muon electric dipole moment. These three observables are highly correlated, and near future measurements of h→µ^{+}µ^{-} will carve an ellipse in the plane of dipole moments for any such model. Together with the future measurements of the electric dipole moment many models able to explain the muon g-2 anomaly can be efficiently tested.


Assuntos
Mésons , Eletricidade
2.
Phys Rev Lett ; 126(19): 191801, 2021 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-34047579

RESUMO

We show that, in a two Higgs doublet model type II extended by vectorlike leptons, the contributions from heavy neutral and charged Higgs bosons to the anomalous magnetic moment of the muon simultaneously feature chiral enhancement from masses of new leptons and tan^{2}ß enhancement from couplings of Higgs bosons. Assuming moderate values of new Yukawa couplings, not exceeding one, that can remain perturbative to very high energy scales, the measured value of muon g-2 can be explained within one standard deviation even with 6.5 TeV leptons or 20 TeV Higgs bosons. Allowing new couplings near the perturbativity limit, these mass ranges extend to 45 TeV for leptons and 185 TeV for Higgs bosons. In spite of the high scale of new physics, this scenario can be completely probed at planned future colliders.

3.
Phys Rev Lett ; 122(18): 181803, 2019 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-31144911

RESUMO

We report on an intriguing observation that the values of all the couplings in the standard model, except those related to first two generations, can be understood from the IR fixed point structure of renormalization group equations in the minimal supersymmetric model extended by one complete vectorlike family with the scale of new physics in a multi-TeV range.

4.
Phys Rev Lett ; 117(6): 061801, 2016 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-27541458

RESUMO

Any new particle charged under SU(3)_{C} and carrying an electric charge will leave an imprint in the diphoton invariant mass spectrum, as it can mediate the gg→γγ process through loops. The combination of properties of loop functions, threshold resummation, and gluon parton distribution functions can result in a peaklike feature in the diphoton invariant mass around twice the mass of a given particle even if the particle is short lived, and thus it does not form a narrow bound state. Using a recent ATLAS analysis, we set upper limits on the combined SU(3)_{C} and electric charge of new particles and indicate future prospects. We also discuss the possibility that the excess of events in the diphoton invariant mass spectrum around 750 GeV originates from loops of a particle with a mass of around 375 GeV.

5.
Phys Rev Lett ; 113(5): 051801, 2014 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-25126909

RESUMO

We discuss an extension of the standard model by fields not charged under standard model gauge symmetry in which the electroweak symmetry breaking is driven by the Higgs quartic coupling itself without the need for a negative mass term in the potential. This is achieved by a scalar field S with a large coupling to the Higgs field at the electroweak scale which is driven to very small values at high energies by the gauge coupling of a hidden symmetry under which S is charged. This model can remain perturbative all the way to the Planck scale. The Higgs boson is fully standard-model-like in its couplings to fermions and gauge bosons. However, the effective cubic and quartic self-couplings of the Higgs boson are significantly enhanced.

6.
Phys Rev Lett ; 100(13): 131804, 2008 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-18517937

RESUMO

We show that, in string models with the minimal supersymmetric standard model residing on D-branes, the bino mass can be generated in a geometrically separated hidden sector. Hypercharge mediation thus naturally teams up with anomaly mediation. The mixed scenario predicts a distinctive yet viable superpartner spectrum, provided that the ratio alpha between the bino and gravitino mass lies in the range 0.05 < or = |alpha| < or = 0.25 and m(3/2) > or = 35 TeV. We summarize some of the experimental signatures of this scenario.

7.
Phys Rev Lett ; 96(21): 211803, 2006 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-16803229

RESUMO

We argue that given the experimental constraints on the Higgs boson mass the least fine-tuned parameter space of the minimal supersymmetric standard model is with negative top-squark masses squared at the grand unification scale. While the top-squark mass squared is typically driven to positive values at the weak scale, the contribution to the Higgs boson mass squared parameter from the running can be arbitrarily small, which reduces the fine-tuning of electroweak symmetry breaking. At the same time the top-squark mixing is necessarily enhanced and the maximal mixing scenario for the Higgs boson mass can be generated radiatively even when starting with negligible mixing at the unification scale. This highly alleviates constraints on possible models for supersymmetry breaking in which fine-tuning is absent.

8.
Phys Rev Lett ; 95(4): 041801, 2005 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-16090795

RESUMO

We demonstrate that the next to minimal supersymmetric model can have small fine-tuning and modest top-squark mass while still evading all experimental constraints. For small tan(beta (large tan(beta), the relevant scenarios are such that there is always (often) a standard-model-like Higgs boson that decays to two lighter--possibly much lighter--Higgs pseudoscalars.

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