scholarly journals Improving fermion mass hierarchy in grand gauge–Higgs unification with localized gauge kinetic terms

2020 ◽  
Vol 80 (10) ◽  
Author(s):  
Nobuhito Maru ◽  
Yoshiki Yatagai

AbstractGrand gauge–Higgs unification of five dimensional SU(6) gauge theory on an orbifold $$S^1/Z_2$$ S 1 / Z 2 with localized gauge kinetic terms is discussed. The Standard model (SM) fermions on one of the boundaries and some massive bulk fermions coupling to the SM fermions on the boundary are introduced, so that they respect an SU(5) symmetry structure. The SM fermion masses including top quark are reproduced by mild tuning the bulk masses and parameters of the localized gauge kinetic terms. Gauge coupling universality is not guaranteed by the presence of the localized gauge kinetic terms and it severely constrains the Higgs vacuum expectation value. Higgs potential analysis shows that the electroweak symmetry breaking occurs by introducing additional bulk fermions in simplified representations. The localized gauge kinetic terms enhance the magnitude of the compactification scale, which helps Higgs boson mass large. Indeed the observed Higgs boson mass 125 GeV is obtained.

1998 ◽  
Vol 13 (10) ◽  
pp. 753-757 ◽  
Author(s):  
ALI AL-NAGHMOUSH ◽  
MURAT ÖZER ◽  
M. O. TAHA

We impose the condition that the eigenvalues of the mass matrix in the shifted Lagrangian density be positive at ϕ=ϕ0, the vacuum expectation value of the scalar field. Using the one-loop effective potential of the standard model, this condition leads to an upper bound on the Higgs boson mass m H :m H <230 GeV, for a top quark mass of 175 GeV.


1997 ◽  
Vol 12 (21) ◽  
pp. 1531-1535 ◽  
Author(s):  
Zhen Yun Fang ◽  
G. López Castro ◽  
J. Pestieau ◽  
J. L. M. Lucio

We assume the stability of the vacuum expectation value of the Higgs boson field under radiative corrections in the context of the standard electroweak theory. We find that this theory behaves as a good effective model already at cutoff energy scales as low as 0.7 TeV. This stability criterion allows us to predict mH=318±13 GeV for the Higgs boson mass.


2022 ◽  
Vol 258 ◽  
pp. 06003
Author(s):  
Giancarlo Rossi

In this talk we describe examples of renormalizable strongly interacting field theories where chiral symmetry, broken at the UV cutoff by the presence of some irrelevant d > 4 operators in the fundamental Lagrangian, is recovered at low energy owing to the tuning of certain Lagrangian parameters. The interference of UV effects with IR features coming from the spontaneous breaking of the recovered chiral symmetry yields non perturbatively generated elementary fermion masses parametrically expressed by formulae of the kind mq ~ Cq(α)ΛRGI with α the gauge coupling constant and ΛRGI the RGI scale of the theory. Upon introducing EW interactions, this mechanism can be extended to give mass to EW bosons and leptons and can thus be used as an alternative to the Higgs scenario. In order to give the top quark and the weak gauge bosons a mass of the phenomenologically correct order of magnitude, the model must necessarily include (yet unobserved) super-strongly interacting massive fermions endowed, besides ordinary Standard Model interactions, with super-strong interactions with a RGI scale, ΛT ΛQCD in the few TeV range. Though limited in its scope (here we ignore hypercharge and leptons and discuss only the case of one family neglecting weak isospin splitting), the model opens the way to a solution of the naturalness problem and an understanding of the fermion mass hierarchy.


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.


1997 ◽  
Vol 12 (08) ◽  
pp. 553-559 ◽  
Author(s):  
Sin Kyu Kang ◽  
Gye T. Park

We study the question of distinguishability of the Higgs sector between the standard model with four generations (SM4) and the minimal supersymmetric standard model with four generations (MSSM4). We find that a gap exists between the SM4 and MSSM4 Higgs boson masses for a range of fourth generation fermion mass considered in the analysis at a fixed top quark mass. We also compare the Higgs boson mass bounds in these models with those in the standard and the minimal supersymmetric standard models.


2021 ◽  
Vol 81 (1) ◽  
Author(s):  
Junxing Pan ◽  
Jung-Hsin Chen ◽  
Xiao-Gang He ◽  
Gang Li ◽  
Jhih-Ying Su

AbstractIn this work, we study the potential of searching for triply charged Higgs boson originating from a complex Higgs quadruplet in the final state with at least three same-sign leptons. A detailed collider analysis of the SM backgrounds and signals is performed at a 100 TeV pp collider for the triply charged Higgs boson mass below 1 TeV and the Higgs quadruplet vacuum expectation value $$v_\Delta $$ v Δ ranging from $$1.5\times 10^{-9}~\text {GeV}$$ 1.5 × 10 - 9 GeV to $$1.3~\text {GeV}$$ 1.3 GeV and the mass splitting $$\Delta m$$ Δ m between the nearby states of the Higgs quadruplet satisfying $$|\Delta m|\lesssim 30~\text {GeV}$$ | Δ m | ≲ 30 GeV . About $$100~\text {fb}^{-1}$$ 100 fb - 1 of data are required at most for $$5\sigma $$ 5 σ discovery. We also revisit the sensitivity at the Large Hadron Collider (LHC) and find that $$5\sigma $$ 5 σ discovery of the triply charged Higgs boson below 1 TeV can be reached for a relatively small $$v_\Delta $$ v Δ . For example, if $$v_\Delta =10^{-6}~\text {GeV}$$ v Δ = 10 - 6 GeV and $$\Delta m=0$$ Δ m = 0 , the integrated luminosity of $$330~\text {fb}^{-1}$$ 330 fb - 1 is needed. But for a relatively large $$v_\Delta $$ v Δ , i.e., $$v_\Delta \gtrsim 10^{-3}~\text {GeV}$$ v Δ ≳ 10 - 3 GeV , the triply charged Higgs boson above about 800 GeV cannot be discovered even in the high-luminosity LHC era. For $$\Delta m>0$$ Δ m > 0 , the cascade decays are open and the sensitivity can be improved depending on the value of $$v_\Delta $$ v Δ .


2021 ◽  
Vol 10 (6) ◽  
Author(s):  
Ketan Patel

A mechanism to generate realistic fermion mass hierarchies based on supersymmetric gauged U(1)_FU(1)F symmetry in flat five-dimensional (5D) spacetime is proposed. The fifth dimension is compactified on S^1/Z_2S1/Z2 orbifold. The standard model fermions charged under the extra abelian symmetry along with their superpartners live in the 5D bulk. Bulk masses of fermions are generated by the vacuum expectation value of N=2N=2 superpartner of U(1)_FU(1)F gauge field, and they are proportional to U(1)_FU(1)F charges of respective fermions. This decides localization of fermions in the extra dimension, which in turn gives rise to exponentially suppressed Yukawa couplings in the effective 4D theory. Anomaly cancellation puts stringent constraints on the allowed U(1)_FU(1)F charges which leads to correlations between the masses of quarks and leptons. We perform an extensive numerical scan and obtain several solutions for anomaly-free U(1)_FU(1)F, which describe the observed pattern of fermion masses and mixing with all the fundamental parameters of order unity. It is found that the possible existence of SM singlet neutrinos substantially improves the spectrum of solutions by offering more freedom in choosing U(1)_FU(1)F charges. The model predicts Z^\primeZ′ boson mediating flavour violating interactions in both the quark and lepton sectors with the couplings which can be explicitly determined from the Yukawa couplings.


2012 ◽  
Vol 2012 (7) ◽  
Author(s):  
Marcin Badziak ◽  
Emilian Dudas ◽  
Marek Olechowski ◽  
Stefan Pokorski

1990 ◽  
Vol 05 (32) ◽  
pp. 2675-2682 ◽  
Author(s):  
CHRISTOPHER T. HILL

We review the recent idea of a mechanism for dynamically breaking the symmetries of the electroweak interactions which relies upon the formation of condensates involving the conventional quarks and leptons, such as the top quark. In particular, such a scheme would indicate that the top quark is heavy, greater than or of order 200 GeV, and gives further predictions for the Higgs boson mass. It may be extended to a fourth generation with new strong TeV scale flavor-interactions.


1991 ◽  
Vol 67 (21) ◽  
pp. 2933-2936 ◽  
Author(s):  
Haukur Arason ◽  
Diego Castao ◽  
Bettina Keszthelyi ◽  
Samuel Mikaelian ◽  
Eric Piard ◽  
...  

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