scholarly journals Higgs potential from Wick rotation in conformal BSM

2019 ◽  
Vol 34 (31) ◽  
pp. 1950257
Author(s):  
Ichiro Oda
Keyword(s):  
Standard Model ◽  
Conformal Symmetry ◽  
Planck Scale ◽  
Mass Term ◽  
Conformal Factor ◽  
Higgs Potential ◽  
Wick Rotation ◽  
Potential Term ◽  
Conformally Invariant ◽  
Invariant Potential

It is well known that in order to make the path integral of general relativity converge, one has to perform the Wick rotation over the conformal factor in addition to the more familiar Wick rotation of the time axis to pass to the spacetime with Euclidean signature. In this paper, we will apply this technique to a scalar field in the conformally invariant scalar–tensor gravity with a conformally invariant beyond-standard-model (BSM). It is then shown that a potential term in the conformally invariant potential, which corresponds to the Higgs mass term in the Higgs potential of the Standard Model (SM), can have a negative coefficient. The change of sign of the potential term naturally induces spontaneous symmetry breakdown of the electroweak gauge symmetry after symmetry breaking of conformal symmetry (local scale symmetry) via the Coleman–Weinberg mechanism around the Planck scale. This study might shed light on the fact that the existence of a stable vacuum in quantum gravity is relevant to that in the SM.

scholarly journals A First-Quantized Model for Unparticles and Gauge Theories around Conformal Window

Universe ◽  
2021 ◽  
Vol 7 (12) ◽  
pp. 471
Author(s):  
Nicolas Boulanger ◽  
Fabien Buisseret ◽  
Guillaume Lhost
Keyword(s):  
Bound States ◽  
Gauge Theories ◽  
Mass Operator ◽  
Conformal Symmetry ◽  
Mass Term ◽  
String Tension ◽  
Coupling Constant ◽  
Scalar Particles ◽  
Conformally Invariant ◽  
Invariant Potential

We first quantize an action proposed by Casalbuoni and Gomis in 2014 that describes two massless relativistic scalar particles interacting via a conformally invariant potential. The spectrum is a continuum of massive states that may be interpreted as unparticles. We then obtain in a similar way the mass operator for a deformed action in which two terms are introduced that break the conformal symmetry: a mass term and an extra position-dependent coupling constant. A simple Ansatz for the latter leads to a mass operator with linear confinement in terms of an effective string tension σ. The quantized model is confining when σ≠0 and its mass spectrum shows Regge trajectories. We propose a tensionless limit in which highly excited confined states reduce to (gapped) unparticles. Moreover, the low-lying confined bound states become massless in the latter limit as a sign of conformal symmetry restoration and the ratio between their masses and σ stays constant. The originality of our approach is that it applies to both confining and conformal phases via an effective interacting model.

scholarly journals Softly broken conformal symmetry and the stability of the electroweak scale

2015 ◽  
Vol 30 (02) ◽  
pp. 1550006 ◽  
Author(s):  
Piotr H. Chankowski ◽  
Adrian Lewandowski ◽  
Krzysztof A. Meissner ◽  
Hermann Nicolai
Keyword(s):  
Field Theory ◽  
Standard Model ◽  
Conformal Symmetry ◽  
Planck Scale ◽  
Effective Field ◽  
Effective Theory ◽  
Minimal Extension ◽  
Fundamental Theory ◽  
Hierarchy Problem ◽  
Physical Scale

We point out a possible mechanism by which the electroweak hierarchy problem can be avoided in the low energy effective quantum field theory. Assuming the existence of a UV complete underlying fundamental theory and treating the cutoff scale Λ of the effective field theory as a real physical scale we argue that the hierarchy problem would be solved if the coefficient in front of quadratic divergences vanished at the scale Λ, and if the effective theory mass parameters fixed at Λ by the fundamental theory were hierarchically smaller than Λ itself. While this mechanism most probably cannot work in the Standard Model if the scale Λ is to be close to the Planck scale, we show that it can work in a minimal extension (Conformal Standard Model) proposed recently for a different implementation of conformal symmetry breaking.

Cotton-Squared Theory

2018 ◽  
Author(s):  
Flavio Mercati
Keyword(s):  
Relational Theory ◽  
Potential Term ◽  
Conformally Invariant ◽  
Invariant Potential ◽  
Cotton Tensor ◽  
Theory Of Gravity

This chapter analyzes a non-viable theory of gravity based on a Jacobi-type action with a conformally invariant potential term based on the square of the Cotton tensor. This theory has striking similarities with Maxwell’s electromagnetism, of which it represents the generalization to spin 2, but unfortunately it is not dynamically consistent, leaving SD as the only viable spatially conformally invariant relational theory of gravity.

scholarly journals Vanishing Higgs potential at the Planck scale in a singlet extension of the standard model

2014 ◽  
Vol 90 (3) ◽  
Author(s):  
Naoyuki Haba ◽  
Hiroyuki Ishida ◽  
Kunio Kaneta ◽  
Ryo Takahashi
Keyword(s):  
Standard Model ◽  
Planck Scale ◽  
Higgs Potential ◽  
The Standard Model

scholarly journals Renormalization group equations of Higgs-R2 inflation

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Yohei Ema ◽  
Kyohei Mukaida ◽  
Jorinde van de Vis
Keyword(s):  
Renormalization Group ◽  
Standard Model ◽  
Planck Scale ◽  
Energy Scale ◽  
Einstein Frame ◽  
Ricci Scalar ◽  
Minimal Coupling ◽  
Renormalization Group Equations ◽  
The Standard Model

Abstract We derive one- and two-loop renormalization group equations (RGEs) of Higgs-R2 inflation. This model has a non-minimal coupling between the Higgs and the Ricci scalar and a Ricci scalar squared term on top of the standard model. The RGEs derived in this paper are valid as long as the energy scale of interest (in the Einstein frame) is below the Planck scale. We also discuss implications to the inflationary predictions and the electroweak vacuum metastability.

scholarly journals Planck Neutrinos as Ultra High Energy Cosmic Rays

2020 ◽  
Vol 29 (1) ◽  
pp. 40-46
Author(s):  
Dmitri L. Khokhlov
Keyword(s):  
Black Holes ◽  
Cosmic Rays ◽  
Standard Model ◽  
Active Galactic Nuclei ◽  
Planck Scale ◽  
Galactic Nuclei ◽  
High Energy ◽  
Ultra High Energy ◽  
High Energy Cosmic Rays ◽  
The Standard Model

AbstractThe studied conjecture is that ultra high energy cosmic rays (UHECRs) are hypothetical Planck neutrinos arising in the decay of the protons falling onto the gravastar. The proton is assumed to decay at the Planck scale into positron and four Planck neutrinos. The supermassive black holes inside active galactic nuclei, while interpreted as gravastars, are considered as UHECR sources. The scattering of the Planck neutrinos by the proton at the Planck scale is considered. The Planck neutrinos contribution to the CR events may explain the CR spectrum from 5 × 1018 eV to 1020 eV. The muon number in the Planck neutrinos-initiated shower is estimated to be larger by a factor of 3/2 in comparison with the standard model that is consistent with the observational data.

scholarly journals A more natural composite Higgs model

2020 ◽  
Vol 2020 (10) ◽  
Author(s):  
Hsin-Chia Cheng ◽  
Yi Chung
Keyword(s):  
Standard Model ◽  
Higgs Model ◽  
Quadratic Term ◽  
Beyond The Standard Model ◽  
Higgs Potential ◽  
Little Higgs ◽  
Composite Higgs ◽  
Partial Compositeness ◽  
Quartic Term ◽  
Natural Composite

Abstract Composite Higgs models provide an attractive solution to the hierarchy problem. However, many realistic models suffer from tuning problems in the Higgs potential. There are often large contributions from the UV dynamics of the composite resonances to the Higgs potential, and tuning between the quadratic term and the quartic term is required to separate the electroweak breaking scale and the compositeness scale. We consider a composite Higgs model based on the SU(6)/Sp(6) coset, where an enhanced symmetry on the fermion resonances can minimize the Higgs quadratic term. Moreover, a Higgs quartic term from the collective symmetry breaking of the little Higgs mechanism can be realized by the partial compositeness couplings between elementary Standard Model fermions and the composite operators, without introducing new elementary fields beyond the Standard Model and the composite sector. The model contains two Higgs doublets, as well as several additional pseudo-Nambu-Goldstone bosons. To avoid tuning, the extra Higgs bosons are expected to be relatively light and may be probed in the future LHC runs. The deviations of the Higgs couplings and the weak gauge boson couplings also provide important tests as they are expected to be close to the current limits in this model.

scholarly journals Dark matter spectra from the electroweak to the Planck scale

2021 ◽  
Vol 2021 (6) ◽  
Author(s):  
Christian W. Bauer ◽  
Nicholas L. Rodd ◽  
Bryan R. Webber
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
Symmetry Breaking ◽  
Planck Scale ◽  
Electroweak Symmetry Breaking ◽  
Indirect Detection ◽  
Electroweak Symmetry ◽  
Stable States ◽  
Decay Spectrum ◽  
Crucial Ingredient

Abstract We compute the decay spectrum for dark matter (DM) with masses above the scale of electroweak symmetry breaking, all the way to the Planck scale. For an arbitrary hard process involving a decay to the unbroken standard model, we determine the prompt distribution of stable states including photons, neutrinos, positrons, and antiprotons. These spectra are a crucial ingredient in the search for DM via indirect detection at the highest energies as being probed in current and upcoming experiments including IceCube, HAWC, CTA, and LHAASO. Our approach improves considerably on existing methods, for instance, we include all relevant electroweak interactions.

scholarly journals Conformal symmetry and the Standard Model

2007 ◽  
Vol 648 (4) ◽  
pp. 312-317 ◽  
Author(s):  
Krzysztof A. Meissner ◽  
Hermann Nicolai
Keyword(s):  
Standard Model ◽  
Conformal Symmetry ◽  
The Standard Model

scholarly journals Weak scale from Planck scale: Mass scale generation in a classically conformal two-scalar system

2020 ◽  
Vol 2020 (3) ◽  
Author(s):  
Junichi Haruna ◽  
Hikaru Kawai
Keyword(s):  
Scalar Field ◽  
Standard Model ◽  
Planck Scale ◽  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
The Other ◽  
Expectation Value ◽  
Weak Scale ◽  
The Standard Model ◽  
The One

Abstract In the standard model, the weak scale is the only parameter with mass dimensions. This means that the standard model itself cannot explain the origin of the weak scale. On the other hand, from the results of recent accelerator experiments, except for some small corrections, the standard model has increased the possibility of being an effective theory up to the Planck scale. From these facts, it is naturally inferred that the weak scale is determined by some dynamics from the Planck scale. In order to answer this question, we rely on the multiple point criticality principle as a clue and consider the classically conformal $\mathbb{Z}_2\times \mathbb{Z}_2$ invariant two-scalar model as a minimal model in which the weak scale is generated dynamically from the Planck scale. This model contains only two real scalar fields and does not contain any fermions or gauge fields. In this model, due to a Coleman–Weinberg-like mechanism, the one-scalar field spontaneously breaks the $ \mathbb{Z}_2$ symmetry with a vacuum expectation value connected with the cutoff momentum. We investigate this using the one-loop effective potential, renormalization group and large-$N$ limit. We also investigate whether it is possible to reproduce the mass term and vacuum expectation value of the Higgs field by coupling this model with the standard model in the Higgs portal framework. In this case, the one-scalar field that does not break $\mathbb{Z}_2$ can be a candidate for dark matter and have a mass of about several TeV in appropriate parameters. On the other hand, the other scalar field breaks $\mathbb{Z}_2$ and has a mass of several tens of GeV. These results will be verifiable in near-future experiments.

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