scholarly journals Global electroweak symmetric vacuum

2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Yang Bai ◽  
Seung J. Lee ◽  
Minho Son ◽  
Fang Ye

Abstract Although the Higgs potential in the Standard Model (SM) contains only a simple electroweak symmetry breaking vacuum in the small field region, additional metastable or global vacua could exist in models beyond the SM. In this paper, we study one intriguing scenario with an additional electroweak symmetric vacuum that could be the global one. For the thermal universe ending at the current metastable vacuum, the electroweak symmetry should stay non-restored at high temperatures. We realize the scenario in a model with Higgs-portal couplings to SM singlet scalars with approximately global O(N) symmetries with a large N. For a large portion of model parameter space, both the quantum and thermal tunneling rates are suppressed such that our current metastable vacuum is long-lived enough. Our scenario predicts order-one changes for the Higgs self-couplings and a large contribution to the signal of the off-shell Higgs invisible decay. It can be partly probed at the LHC Run 3 and well tested at the high luminosity LHC. We also discuss the subcritical (anti-de Sitter) bubbles from the thermal tunneling that could have a large population and interesting cosmological implications.

2008 ◽  
Vol 23 (25) ◽  
pp. 4107-4124 ◽  
Author(s):  
TAO HAN

The LHC (Large Hadron Collider) will be a top-quark factory. With 80 million pairs of top quarks and an additional 34 million single tops produced annually at the designed high luminosity, the properties of this particle will be studied to a great accuracy. The fact that the top quark is the heaviest elementary particle in the Standard Model with a mass right at the electroweak scale makes it tempting to contemplate its role in electroweak symmetry breaking, as well as its potential as a window to unknown new physics at the TeV scale. We summarize the expectations for top-quark physics at the LHC, and outline new physics scenarios in which the top quark is crucially involved.


2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Sanjoy Mandal ◽  
Rahul Srivastava ◽  
José W. F. Valle

Abstract We investigate the stability of Higgs potential in inverse seesaw models. We derive the full two-loop RGEs of the relevant parameters, such as the quartic Higgs self-coupling, taking thresholds into account. We find that for relatively large Yukawa couplings the Higgs quartic self-coupling goes negative well below the Standard Model instability scale ∼ 1010 GeV. We show, however, that the “dynamical” inverse seesaw with spontaneous lepton number violation can lead to a completely consistent and stable Higgs vacuum up to the Planck scale.


2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
Véronique Bernard ◽  
Sébastien Descotes-Genon ◽  
Luiz Vale Silva

Abstract We consider a left-right symmetric extension of the Standard Model where the spontaneous breakdown of the left-right symmetry is triggered by doublets. The electroweak ρ parameter is protected from large corrections in this Doublet Left-Right Model (DLRM), contrary to the triplet case. This allows in principle for more diverse patterns of symmetry breaking. We consider several constraints on the gauge and scalar sectors of DLRM: the unitarity of scattering processes involving gauge bosons with longitudinal polarisations, the radiative corrections to the muon ∆r parameter and the electroweak precision observables measured at the Z pole and at low energies. Combining these constraints within the frequentist CKMfitter approach, we see that the fit pushes the scale of left-right symmetry breaking up to a few TeV, while favouring an electroweak symmetry breaking triggered not only by the SU(2)L×SU(2)R bi-doublet, which is the case most commonly considered in the literature, but also by the SU(2)L doublet.


2004 ◽  
Vol 13 (04) ◽  
pp. 641-657 ◽  
Author(s):  
CIPRIAN DARIESCU

The Einstein–Gordon equations for Friedmann–Robertson–Walker (FRW) geometries in feedback reaction with the quartically self-interacting physical field, arisen from the spontaneous Z2-symmetry breaking, are explicitly formulated. The fixed point exact solutions to the "inner parity" non-invariant Einstein–Gordon system (mandatory) describe (k=-1)-FRW manifolds which actually are either Milne or anti-de Sitter Universes. Setting the Z2-invariance breaking scale at one of the electroweak symmetry, we speculate on the cosmological implications of the Higgs–anti-de Sitter bubbles and derive a set of closed-form solutions to the S2-cobordism with a spatially-flat FRW Universe.


2003 ◽  
Vol 18 (14) ◽  
pp. 967-975 ◽  
Author(s):  
J. G. KÖRNER ◽  
CHUN LIU

A supersymmetric model with two copies of the Standard Model gauge groups is constructed in the gauge mediated supersymmetry breaking scenario. The supersymmetry breaking messengers are in a simple form. The Standard Model is obtained after first step gauge symmetry breaking. In the case of one copy of the gauge interactions being strong, a scenario of electroweak symmetry breaking is discussed, and the gauginos are generally predicted to be heavier than the sfermions.


2002 ◽  
Vol 17 (23) ◽  
pp. 3300-3317
Author(s):  
FABIO ZWIRNER

The present experimental and theoretical knowledge of the physics of electroweak symmetry breaking is reviewed. Data still favor a light Higgs boson, of a kind that can be comfortably accommodated in the Standard Model or in its Minimal Supersymmetric extension, but exhibit a non-trivial structure that leaves some open questions. The available experimental information may still be reconciled with the absence of a light Higgs boson, but the price to pay looks excessive. Recent theoretical ideas, linking the weak scale with the size of possible extra spatial dimensions, are briefly mentioned. It is stressed once more that experiments at high-energy colliders, such as the Tevatron and the LHC, are the crucial tool for eventually solving the Higgs puzzle.


2014 ◽  
Vol 89 (1) ◽  
Author(s):  
Emidio Gabrielli ◽  
Matti Heikinheimo ◽  
Kristjan Kannike ◽  
Antonio Racioppi ◽  
Martti Raidal ◽  
...  

1993 ◽  
Vol 08 (26) ◽  
pp. 2465-2470 ◽  
Author(s):  
ANIRBAN KUNDU ◽  
TRIPTESH DE ◽  
BINAYAK DUTTA-ROY

The dynamical electroweak symmetry breaking of the Standard Model triggered by a top quark condensate (induced by an effective strong interaction, associated with a highenergy scale, of the form [Formula: see text]) usually requires an embarrassingly large top quark mass. A suggestion that this problem could be avoided through the introduction of an additional interaction [Formula: see text] (where [Formula: see text] are SU(3)c generators á la Okubo) is analyzed using the renormalization group approach. The mass of the top quark and the concomitant emergence of colored composite bosons is discussed.


Author(s):  
Nobuhito Maru ◽  
Yoshiki Yatagai

Abstract Grand gauge-Higgs unification of 5D $SU(6)$ gauge theory on an orbifold $S^1/Z_2$ is discussed. The Standard Model (SM) fermions are introduced on one of the boundaries and some massive bulk fields are also introduced so that they couple to the SM fermions through the mass terms on the boundary. Integrating out the bulk fields generates SM fermion masses with exponentially small bulk mass dependences. The SM fermion masses except for the top quark are shown to be reproduced by mild tuning of the bulk masses. The one-loop Higgs potential is calculated and it is shown that electroweak symmetry breaking occurs by introducing additional bulk fields. The Higgs boson mass is also computed.


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