scholarly journals BOSONIC SEESAW AND A SOLUTION TO THE μ PROBLEM IN THE UNPARTICLE PHYSICS

2010 ◽  
Vol 25 (09) ◽  
pp. 691-701
Author(s):  
TATSURU KIKUCHI

Recently, conceptually new physics beyond the Standard Model has been proposed by Georgi, where a new physics sector becomes conformal and provides "unparticle" which couples to the Standard Model sector through higher dimensional operators in low energy effective theory. Among several possibilities, we focus on operators involving the unparticle and Higgs boson. Once the Higgs develops the vacuum expectation value (VEV), the conformal symmetry is broken and as a result, the mixing between the unparticle and the Higgs boson emerges. In the former part of this paper, we consider a natural realization of bosonic seesaw in the context of unparticle physics. In this framework, the negative mass squared or the electroweak symmetry breaking vacuum is achieved as a result of mass matrix diagonalization. So, the bosonic seesaw mechanism for the electroweak symmetry breaking can naturally be understood in the framework of unparticle physics. In the latter part of this paper, we consider the unparticle as a hidden sector of supersymmetry breaking, and give some phenomenological consequences of this scenario. The result shows that there is a possibility for the unparticle as a hidden sector in SUSY breaking sector, and can provide a solution to the μ problem in SUSY models.

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Timothy Cohen ◽  
Nathaniel Craig ◽  
Xiaochuan Lu ◽  
Dave Sutherland

Abstract There are two canonical approaches to treating the Standard Model as an Effective Field Theory (EFT): Standard Model EFT (SMEFT), expressed in the electroweak symmetric phase utilizing the Higgs doublet, and Higgs EFT (HEFT), expressed in the broken phase utilizing the physical Higgs boson and an independent set of Goldstone bosons. HEFT encompasses SMEFT, so understanding whether SMEFT is sufficient motivates identifying UV theories that require HEFT as their low energy limit. This distinction is complicated by field redefinitions that obscure the naive differences between the two EFTs. By reformulating the question in a geometric language, we derive concrete criteria that can be used to distinguish SMEFT from HEFT independent of the chosen field basis. We highlight two cases where perturbative new physics must be matched onto HEFT: (i) the new particles derive all of their mass from electroweak symmetry breaking, and (ii) there are additional sources of electroweak symmetry breaking. Additionally, HEFT has a broader practical application: it can provide a more convergent parametrization when new physics lies near the weak scale. The ubiquity of models requiring HEFT suggests that SMEFT is not enough.


2007 ◽  
Vol 22 (30) ◽  
pp. 5502-5512
Author(s):  
D. I. KAZAKOV

Review of recent developments in attempts to go beyond the Standard Model is given. We concentrate on three main unresolved problems: mechanism of electroweak symmetry breaking, expected new physics at the TeV scale (mainly SUSY) and the origin of the Dark matter.


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.


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

2014 ◽  
Vol 29 (21) ◽  
pp. 1444007
Author(s):  
George Wei-Shu Hou

Fermion mass generation in the standard model was invented by Weinberg, while it is an old notion that strong Yukawa coupling could be the agent of electroweak symmetry breaking. Observation of the 126 GeV boson has crashed the prospects for such a heavy chiral quark doublet Q. However, the dilaton possibility can only be ruled out by confirming vector boson fusion with Run 2 data at the LHC, which starts only in 2015. We recast the [Formula: see text] condensation scenario as Fermi–Yang model v2.0. A Gap Equation has been constructed, with numerical solution demonstrating dynamical mQ generation; scale invariance of this equation may be consistent with a dilaton. Other consequences to be checked are [Formula: see text] "annihilation stars," and enhanced Bd →μ+μ-, KL →π0νν, and possibly sin ϕs. If verified in Nature, the Agent of BEH mechanism would differ from current perception, the 126 GeV boson would be the first New Physics at the LHC, and we would have enough CP violation for baryogenesis.


2013 ◽  
Vol 28 (02) ◽  
pp. 1330004 ◽  
Author(s):  
ALEKSANDR AZATOV ◽  
JAMISON GALLOWAY

In this review, we discuss methods of parsing direct information from collider experiments regarding the Higgs boson and describe simple ways in which experimental likelihoods can be consistently reconstructed and interfaced with model predictions in pertinent parameter spaces. We review prevalent scenarios for extending the electroweak symmetry breaking sector and emphasize their predictions for nonstandard Higgs phenomenology that could be observed in large hadron collider (LHC) data if naturalness is realized in particular ways. Specifically we identify how measurements of Higgs couplings can be used to imply the existence of new physics at particular scales within various contexts. The most dominant production and decay modes of the Higgs-like state observed in the early data sets have proven to be consistent with predictions of the Higgs boson of the Standard Model, though interesting directions in subdominant channels still exist and will require our careful attention in further experimental tests. Slightly anomalous rates in certain channels at the early LHC have spurred effort in model building and spectra analyses of particular theories, and we discuss these developments in some detail. Finally, we highlight some parameter spaces of interest in order to give examples of how the data surrounding the new state can most effectively be used to constrain specific models of weak scale physics.


2015 ◽  
Vol 30 (31) ◽  
pp. 1550160 ◽  
Author(s):  
Ernesto A. Matute

Recently we proposed a model for light Dirac neutrinos in which two right-handed (RH) neutrinos per generation are added to the particles of the Standard Model (SM), implemented with the symmetry of fermionic contents. The ordinary one is decoupled via the high scale type-I seesaw mechanism, while the extra pairs off with its left-handed (LH) partner. The symmetry of lepton and quark contents was merely used as a guideline to the choice of parameters because it is not a proper symmetry. Here we argue that the underlying symmetry to take for this correspondence is presymmetry, the hidden electroweak symmetry of the SM extended with RH neutrinos defined by transformations which exchange lepton and quark bare states with the same electroweak charges and no Majorana mass terms in the underlying Lagrangian. It gives a topological character to fractional charges, relates the number of families to the number of quark colors, and now guarantees the great disparity between the couplings of the two RH neutrinos. Thus, Dirac neutrinos with extremely small masses appear as natural predictions of presymmetry, satisfying the ’t Hooft’s naturalness conditions in the extended seesaw where the extra RH neutrinos serve to adulterate the mass properties in the low scale effective theory, which retains without extensions the gauge and Higgs sectors of the SM. However, the high energy threshold for the seesaw implies new physics to stabilize the quantum corrections to the Higgs boson mass in agreement with the naturalness requirement.


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