scholarly journals Corrections to Yukawa couplings from higher dimensional operators in a natural SUSY SO(10) and HL-LHC implications

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Amin Aboubrahim ◽  
Pran Nath ◽  
Raza M. Syed
Keyword(s):  
Gauge Group ◽  
Hadron Collider ◽  
High Energy ◽  
Spontaneous Breaking ◽  
Electroweak Symmetry ◽  
Yukawa Couplings ◽  
A Value ◽  
Higher Dimensional ◽  
Higgs Fields ◽  
Natural Way

Abstract We consider a class of unified models based on the gauge group SO(10) which with appropriate choice of Higgs representations generate in a natural way a pair of light Higgs doublets needed to accomplish electroweak symmetry breaking. In this class of models higher dimensional operators of the form matter-matter-Higgs-Higgs in the superpotential after spontaneous breaking of the GUT symmetry generate contributions to Yukawa couplings which are comparable to the ones from cubic interactions. Specifically we consider an SO(10) model with a sector consisting of 126 + $$ \overline{126} $$ 126 ¯ + 210 of heavy Higgs which breaks the GUT symmetry down to the standard model gauge group and a sector consisting of 2 × 10 + 120 of light Higgs fields. In this model we compute the corrections from the quartic interactions to the Yukawa couplings for the top and the bottom quarks and for the tau lepton. It is then shown that inclusion of these corrections to the GUT scale Yukawas allows for consistency of the top, bottom and tau masses with experiment for low tan β with a value as low as tan β of 5–10. We compute the sparticle spectrum for a set of benchmarks and find that satisfaction of the relic density is achieved via a compressed spectrum and coannihilation and three sets of coannihilations appear: chargino-neutralino, stop-neutralino and stau-neutralino. We investigate the chargino-neutralino coannihilation in detail for the possibility of observation of the light chargino at the high luminosity LHC (HL-LHC) and at the high energy LHC (HE-LHC) which is a possible future 27 TeV hadron collider. It is shown that all benchmark models but one can be discovered at HL-LHC and all would be discoverable at HE-LHC. The ones discoverable at both machines require a much shorter time scale and a lower integrated luminosity at HE-LHC.

scholarly journals THE MIRAGE OF THE FERMI SCALE

2013 ◽  
Vol 28 (32) ◽  
pp. 1350140 ◽  
Author(s):  
OLEG ANTIPIN ◽  
FRANCESCO SANNINO ◽  
KIMMO TUOMINEN
Keyword(s):  
Model Building ◽  
Hadron Collider ◽  
High Energy ◽  
Low Energy ◽  
The Other ◽  
Electroweak Symmetry ◽  
Light Higgs Boson ◽  
Very High Energy ◽  
Very High ◽  
Natural Way

The discovery of a light Higgs boson at Large Hadron Collider may be suggesting that we need to revise our model building paradigms to understand the origin of the weak scale. We explore the possibility that the Fermi scale is not fundamental but rather a derived one, i.e. a low energy mirage. We show that this scenario emerges in a very natural way in models previously used to break the electroweak symmetry dynamically and suggest a simple dynamical framework for this idea. In our model the electroweak scale results from the interplay between two very high energy scales, one typically of the order of Λ UV ~ 1010 GeV and the other around MU ~ 1016 GeV , although other values are also possible.

scholarly journals VECTOR BOSON SCATTERING AND BOUNDARY CONDITIONS IN KALUZA–KLEIN TOY MODEL

2012 ◽  
Vol 27 (17) ◽  
pp. 1250098 ◽  
Author(s):  
PETR MORÁVEK ◽  
JIŘÍ HOŘEJŠÍ
Keyword(s):  
Scattering Amplitudes ◽  
Boundary Conditions ◽  
Vector Boson ◽  
High Energy ◽  
Electroweak Symmetry ◽  
Least Action ◽  
Higher Dimensional ◽  
Principle Of Least Action ◽  
Vector Bosons ◽  
Vector Boson Scattering

We study a simple higher-dimensional toy model of electroweak symmetry breaking, in particular a pure gauge 5D theory on flat background with one extra finite space dimension. The principle of least action and the requirement of gauge independence of scattering amplitudes are used to determine the possible choices of boundary conditions. We demonstrate that for any of these choices the scattering amplitudes of vector bosons do not exhibit power-like growth in the high energy limit. Our analysis is an extension and generalization of the results obtained previously by other authors.

scholarly journals Moderately suppressed dimension-five proton decay in a flipped SU(5) model

2022 ◽  
Vol 2022 (1) ◽  
Author(s):  
Naoyuki Haba ◽  
Toshifumi Yamada
Keyword(s):  
Mass Term ◽  
Proton Decay ◽  
Model Structure ◽  
Ckm Matrix ◽  
Decay Modes ◽  
Yukawa Couplings ◽  
Higher Dimensional ◽  
Gut Scale ◽  
Higgs Fields ◽  
Current Bound

Abstract We study colored Higgsino-mediated proton decay (dimension-five proton decay) in a model based on the flipped SU(5) GUT. In the model, the GUT-breaking 10, $$ \overline{\mathbf{10}} $$ 10 ¯ fields have a GUT-scale mass term and gain VEVs through higher-dimensional operators, which induces an effective mass term between the color triplets in the 5, $$ \overline{\mathbf{5}} $$ 5 ¯ Higgs fields that is not much smaller than the GUT scale. This model structure gives rise to observable dimension-five proton decay, and at the same time achieves moderate suppression on dimension-five proton decay that softens the tension with the current bound on Γ(p → K+$$ \overline{\nu} $$ ν ¯ ). We investigate the flavor dependence of the Wilson coefficients of the operators relevant to dimension-five proton decay, by relating them with diagonalized Yukawa couplings and CKM matrix components in MSSM, utilizing the fact that the GUT Yukawa couplings are in one-to-one correspondence with the MSSM Yukawa couplings in flipped models. Then we numerically evaluate the Wilson coefficients, and predict the distributions of the ratios of the partial widths of various proton decay modes.

scholarly journals Perspectives and outlook from HEP window on the universe

2019 ◽  
Vol 34 (02) ◽  
pp. 1930002 ◽  
Author(s):  
George Wei-Shu Hou
Keyword(s):  
High Energy Physics ◽  
Hadron Collider ◽  
High Energy ◽  
New Physics ◽  
Personal Perspective ◽  
First Year ◽  
25Th Anniversary ◽  
Yukawa Couplings ◽  
The Universe ◽  
Energy Physics

This brief review grew out from the HEP concluding talk of the 25th Anniversary of the Rencontres du Vietnam, held in August 2018, at Quy Nhon. The first two-thirds gives a summary and highlights, or snapshot, of High Energy Physics at the end of Large Hadron Collider (LHC) Run 2. It can be viewed as the combined effort of the program organizers, the invited plenary speakers, and finally filtered into the present mosaic. It certainly should not be viewed as comprehensive. In the second one-third, a more personal perspective and outlook is given, including my take on the flavor anomalies, and why the next three years, the period of Long Shutdown 2 plus first year (or more) of LHC Run 3, would be bright and flavorful, with much hope for uncovering New Physics. We advocate extra Yukawa couplings as the most likely, next, New Physics to be tested, the effect of which is already written in our Matter Universe.

Z′-GAUGE BOSON AND INFLATION IN THE ELECTROWEAK SCALE

1999 ◽  
Vol 14 (20) ◽  
pp. 1365-1369 ◽  
Author(s):  
B. B. DEO
Keyword(s):  
Symmetry Group ◽  
Gauge Boson ◽  
High Energy ◽  
Radiative Corrections ◽  
Electroweak Symmetry ◽  
Electroweak Scale ◽  
A Value ◽  
Weakly Coupled

An enlarged electroweak symmetry group SU L(2)⊗ U Y(1)⊗ U ′(1) is broken to U em(1) at σ=246 GeV due to radiative corrections. The resulting Coleman–Weinberg potential explains the inflation at 246 GeV scale successfully and the mass of the additional weakly coupled gauge boson Z′ has a value close to 252 GeV accessible to present-day high energy accelerators.

scholarly journals Effective operator bases for beyond Standard Model scenarios: an EFT compendium for discoveries

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Upalaparna Banerjee ◽  
Joydeep Chakrabortty ◽  
Suraj Prakash ◽  
Shakeel Ur Rahaman ◽  
Michael Spannowsky
Keyword(s):  
Standard Model ◽  
High Energy ◽  
Beyond The Standard Model ◽  
Minimal Extension ◽  
Effective Operator ◽  
Abelian Gauge ◽  
Gauge Symmetries ◽  
Higher Dimensional ◽  
The Standard Model ◽  
Mass Dimension

Abstract It is not only conceivable but likely that the spectrum of physics beyond the Standard Model (SM) is non-degenerate. The lightest non-SM particle may reside close enough to the electroweak scale that it can be kinematically probed at high-energy experiments and on account of this, it must be included as an infrared (IR) degree of freedom (DOF) along with the SM ones. The rest of the non-SM particles are heavy enough to be directly experimentally inaccessible and can be integrated out. Now, to capture the effects of the complete theory, one must take into account the higher dimensional operators constituted of the SM DOFs and the minimal extension. This construction, BSMEFT, is in the same spirit as SMEFT but now with extra IR DOFs. Constructing a BSMEFT is in general the first step after establishing experimental evidence for a new particle. We have investigated three different scenarios where the SM is extended by additional (i) uncolored, (ii) colored particles, and (iii) abelian gauge symmetries. For each such scenario, we have included the most-anticipated and phenomenologically motivated models to demonstrate the concept of BSMEFT. In this paper, we have provided the full EFT Lagrangian for each such model up to mass dimension 6. We have also identified the CP, baryon (B), and lepton (L) number violating effective operators.

scholarly journals Generalized vanishing theorems for Yukawa couplings in heterotic compactifications

2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
Lara B. Anderson ◽  
James Gray ◽  
Magdalena Larfors ◽  
Matthew Magill ◽  
Robin Schneider
Keyword(s):  
Vector Bundles ◽  
Geometric Approach ◽  
Low Energy ◽  
Geometric Features ◽  
Vanishing Theorems ◽  
Vanishing Theorem ◽  
Alternative Derivation ◽  
Yukawa Couplings ◽  
Geometric Methods ◽  
Higher Dimensional

Abstract Heterotic compactifications on Calabi-Yau threefolds frequently exhibit textures of vanishing Yukawa couplings in their low energy description. The vanishing of these couplings is often not enforced by any obvious symmetry and appears to be topological in nature. Recent results used differential geometric methods to explain the origin of some of this structure [1, 2]. A vanishing theorem was given which showed that the effect could be attributed, in part, to the embedding of the Calabi-Yau manifolds of interest inside higher dimensional ambient spaces, if the gauge bundles involved descended from vector bundles on those larger manifolds. In this paper, we utilize an algebro-geometric approach to provide an alternative derivation of some of these results, and are thus able to generalize them to a much wider arena than has been considered before. For example, we consider cases where the vector bundles of interest do not descend from bundles on the ambient space. In such a manner we are able to highlight the ubiquity with which textures of vanishing Yukawa couplings can be expected to arise in heterotic compactifications, with multiple different constraints arising from a plethora of different geometric features associated to the gauge bundle.

scholarly journals Electroweak symmetry breaking in the inverse seesaw mechanism

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Sanjoy Mandal ◽  
Rahul Srivastava ◽  
José W. F. Valle
Keyword(s):  
Planck Scale ◽  
Lepton Number ◽  
Electroweak Symmetry Breaking ◽  
Electroweak Symmetry ◽  
Seesaw Mechanism ◽  
Yukawa Couplings ◽  
Lepton Number Violation ◽  
Higgs Vacuum ◽  
The Standard Model ◽  
The Stability

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.

scholarly journals LIGHT COMPOSITE HIGGS: LCH @ LHC

2005 ◽  
Vol 20 (27) ◽  
pp. 6133-6148 ◽  
Author(s):  
FRANCESCO SANNINO
Keyword(s):  
Gauge Group ◽  
Higgs Mass ◽  
Cold Dark Matter ◽  
Precision Measurements ◽  
Chiral Phase ◽  
Symmetric Representation ◽  
Composite Higgs ◽  
Higher Dimensional ◽  
The One ◽  
Intrinsic Scale

Here I summarize some of the salient features of technicolor theories with technifermions in higher dimensional representations of the technicolor gauge group. The expected phase diagram as function of number of flavors and colors for the two index (anti)symmetric representation of the gauge group is reviewed. After having constructed the simplest walking technicolor theory one can show that it is not at odds with the precision measurements. The simplest theory also requires, for consistency, a fourth family of heavy leptons. The latter may result in an interesting signature at LHC. In the case of a fourth family of leptons with ordinary lepton hypercharge the new heavy neutrino can be a natural candidate of cold dark matter. New theories will also be proposed in which the critical number of flavors needed to enter the conformal window is higher than in the one with fermions in the two-index symmetric representation, but lower than in the walking technicolor theories with fermions only in the fundamental representation of the gauge group. Due to the near conformal/chiral phase transition the composite Higgs is very light compared to the intrinsic scale of the technicolor theory. For the two technicolor theory the composite Higgs mass is predicted not to exceed 150 GeV.

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