scholarly journals Towards a non-perturbative approach to the Hierarchy problem

2018 ◽  
Vol 191 ◽  
pp. 02022
Author(s):  
Andrey Shkerin
Keyword(s):  
Planck Scale ◽  
Low Energy ◽  
Successful Implementation ◽  
Hierarchy Problem ◽  
Perturbative Approach ◽  
Strong Gravity ◽  
Nonperturbative Effect

In this report, based on [1], we suggest that the hierarchy between the Electroweak (EW) and the Planck scales can emerge due to a nonperturbative effect that relates low-energy and strong-gravity physics. In this mechanism, the EW scale results from an exponential suppression of the Planck scale by an instanton. We illustrate the mechanism in a toy-model example and discuss what features of a theory in the strong-gravity domain would favor its successful implementation.

scholarly journals INFINITE STATISTICS, SYMMETRY BREAKING AND COMBINATORIAL HIERARCHY

2009 ◽  
Vol 24 (18) ◽  
pp. 1425-1435 ◽  
Author(s):  
VLADIMIR SHEVCHENKO
Keyword(s):  
Symmetry Breaking ◽  
Mechanical Model ◽  
Degrees Of Freedom ◽  
High Energy ◽  
Low Energy ◽  
Effective Theory ◽  
Quantum Mechanical ◽  
Hierarchy Problem ◽  
Induced Gravity ◽  
Large Numbers

The physics of symmetry breaking in theories with strongly interacting quanta obeying infinite (quantum Boltzmann) statistics known as quons is discussed. The picture of Bose/Fermi particles as low energy excitations over nontrivial quon condensate is advocated. Using induced gravity arguments, it is demonstrated that the Planck mass in such low energy effective theory can be factorially (in number of degrees of freedom) larger than its true ultraviolet cutoff. Thus, the assumption that statistics of relevant high energy excitations is neither Bose nor Fermi but infinite can remove the hierarchy problem without necessity to introduce any artificially large numbers. Quantum mechanical model illustrating this scenario is presented.

scholarly journals QUANTUM EVOLUTION IN SPACE–TIME FOAM

1999 ◽  
Vol 14 (26) ◽  
pp. 4079-4120 ◽  
Author(s):  
LUIS J. GARAY
Keyword(s):  
Quantum Coherence ◽  
Planck Scale ◽  
Space Time ◽  
Low Energy ◽  
Quantum Evolution ◽  
Minimum Length ◽  
Resolution Limit ◽  
Large Length ◽  
Non Local ◽  
Quantum Mechanical Systems

In this work, I review some aspects concerning the evolution of quantum low-energy fields in a foamlike space–time, with involved topology at the Planck scale but with a smooth metric structure at large length scales, as follows. Quantum gravitational fluctuations may induce a minimum length thus introducing an additional source of uncertainty in physics. The existence of this resolution limit casts doubts on the metric structure of space–time at the Planck scale and opens a doorway to nontrivial topologies, which may dominate Planck scale physics. This foamlike structure of space–time may show up in low-energy physics through loss of quantum coherence and mode-dependent energy shifts, for instance, which might be observable. Space–time foam introduces non-local interactions that can be modeled by a quantum bath, and low-energy fields evolve according to a master equation that displays such effects. Similar laws are also obtained for quantum mechanical systems evolving according to good real clocks, although the underlying Hamiltonian structure in this case establishes serious differences among both scenarios.

Complex geometry of space–time motivated by gravity’s rainbow

2019 ◽  
Vol 97 (5) ◽  
pp. 558-561
Author(s):  
Faizan Bhat ◽  
Mussadiq H. Qureshi ◽  
Manzoor A. Malik ◽  
Asif Iqbal
Keyword(s):  
Imaginary Part ◽  
Complex Space ◽  
Complex Geometry ◽  
Planck Scale ◽  
Space Time ◽  
Low Energy ◽  
Gravity’S Rainbow ◽  
Gravity's Rainbow ◽  
Energy Approximation ◽  
Planck Energy

In this paper, we generalize the formalism of gravity’s rainbow to complex space–time. The resulting geometry depends on the energy of the probe in such a way that the usual real manifold is the low energy approximation of the Planck scale geometry of space–time. So, our formalism agrees with all the observational data about our space–time being real, as at the scale these experiments are preformed, the imaginary part of the geometry is suppressed by Planck energy. However, the imaginary part of the geometry becomes important near the Planck energy, and so it cannot be neglected near the Planck scale. So, the Planck scale geometry of space–time is described by a complex manifold.

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.

scholarly journals Hierarchy problem, gauge coupling unification at the Planck scale, and vacuum stability

2015 ◽  
Vol 900 ◽  
pp. 244-258 ◽  
Author(s):  
Naoyuki Haba ◽  
Hiroyuki Ishida ◽  
Ryo Takahashi ◽  
Yuya Yamaguchi
Keyword(s):  
Planck Scale ◽  
Gauge Coupling ◽  
Hierarchy Problem ◽  
Vacuum Stability

scholarly journals Flavor anomalies from asymptotically safe gravity

2021 ◽  
Vol 81 (4) ◽  
Author(s):  
Kamila Kowalska ◽  
Enrico Maria Sessolo ◽  
Yasuhiro Yamamoto
Keyword(s):  
Hadron Collider ◽  
Planck Scale ◽  
Mass Range ◽  
Low Energy ◽  
Matrix Elements ◽  
Yukawa Couplings ◽  
Leptonic Decays ◽  
Scalar Leptoquark ◽  
S 100 ◽  
Gravity Driven

AbstractWe use the framework of asymptotically safe quantum gravity to derive predictions for scalar leptoquark solutions to the $$b\rightarrow s$$ b → s and $$b\rightarrow c$$ b → c flavor anomalies. The presence of an interactive UV fixed point in the system of gauge and Yukawa couplings imposes a set of boundary conditions at the Planck scale, which allows one to determine low-energy values of the leptoquark Yukawa matrix elements. As a consequence, the allowed leptoquark mass range can be significantly narrowed down. We find that a consistent gravity-driven solution to the $$b\rightarrow s$$ b → s anomalies predicts a leptoquark with the mass of 4–7 $$\,\mathrm {TeV}$$ TeV , entirely within the reach of a future hadron-hadron collider with $$\sqrt{s}=100\,\mathrm {TeV}$$ s = 100 TeV . Conversely, in the case of the $$b\rightarrow c$$ b → c anomalies the asymptotically safe gravity framework predicts a leptoquark mass at the edge of the current LHC bounds. Complementary signatures appear in flavor observables, namely the (semi)leptonic decays of B and D mesons and kaons.

scholarly journals Flavour physics and extra-dimensions

2018 ◽  
Vol 179 ◽  
pp. 01006
Author(s):  
Abhishek M. Iyer
Keyword(s):  
Extra Dimensions ◽  
Neutral Current ◽  
Low Energy ◽  
Hierarchy Problem ◽  
Fermionic Sector ◽  
Supersymmetric Version ◽  
Flavour Violation ◽  
Standard Scenario ◽  
Lepton Decays ◽  
The Right

Randall-Sundrum (RS) model of warped extra-dimensions were originally proposed to explain the Planck-weak scale hierarchy. It was soon realised that modifications of the original setup, by introducing the fields in the bulk, has several interesting features. In particular it imbues a rich flavour structure to the fermionic sector thereby offering an understanding of the Yukawa hierarchy problem. This construction is also useful in explaining the recently observed deviations in the decay of the B mesons. We consider two scenarios to this effect : A) Right handed muon fields coupled more to NP that the corresponding muon doublets (unorthodox case). Non-universality exists in the right handed sector. B) Standard scenario with anomalies explained primarily by non-universal couplings to the lepton doublets. Further, we establish correlation with the parameter space consistent with the flavour anomalies in the neutral current sector and obtain predictions for rare K- decay which are likely to be another candle for NP with increased precision. The prediction for rare K- decays are different according to the scenario, thereby serving as a useful discriminatory tool. We also discussthe large flavour violation in the lepton sector and present an example with the implementation of bulk leptonic MFV which is essential to realize the model with low KK scales. Further we consider a radical solution, called GUT RS models, where the RS geometry can work as theory of flavour in the absence of flavour symmetries. In this case the low energy brane corresponds to the GUT scale as a result of which RS is no longer solution to the gauge hierarchy problem. The Kaluza Klein (KK) modes in this setup are naturally heavy due to which the low energy constraints can be easily avoided. We use this framework to discuss the supersymmetric version of the RS model and provide means to test this scenario by considering rare lepton decays like τ → μγ.

POSSIBLE LOW ENERGY MANIFESTATIONS OF STRINGS AND GRAVITY

2010 ◽  
Vol 19 (08n10) ◽  
pp. 1339-1350
Author(s):  
I. ANTONIADIS
Keyword(s):  
Theoretical Framework ◽  
Low Energy ◽  
Mass Hierarchy ◽  
Hierarchy Problem ◽  
Mass Hierarchy Problem

Lowering the string scale in the TeV region provides a theoretical framework for solving the mass hierarchy problem and unifying all interactions. The apparent weakness of gravity can then be accounted by the existence of large internal dimensions, in the submillimeter region, and transverse to a braneworld where our universe must be confined. The author reviews the main properties of this scenario and its implications for observations at both particle colliders, and in non-accelerator gravity experiments.

scholarly journals On gapped continuum resonance spectra

2021 ◽  
pp. 2141002
Author(s):  
Eugenio Megías ◽  
Mariano Quirós
Keyword(s):  
Standard Model ◽  
Cross Section ◽  
Mass Formula ◽  
Planck Scale ◽  
Hierarchy Problem ◽  
Linear Dilaton ◽  
Curvature Parameter ◽  
Kaluza Klein ◽  
Fundamental Formula ◽  
Conformal Coordinates

In this work, we study a warped five-dimensional (5D) model with ultraviolet (UV) and infrared (IR) branes, that solves the hierarchy problem with a fundamental 5D Planck scale [Formula: see text], and curvature parameter [Formula: see text], of the order of the 4D Planck mass [Formula: see text] TeV. The model exhibits a continuum of Kaluza–Klein (KK) modes with different mass gaps, at the TeV scale, for all fields. We have computed Green’s functions and spectral densities, and shown how the presence of a continuum KK spectrum can produce an enhancement in the cross-section of some Standard Model processes. The metric is linear near the IR, in conformal coordinates, as in the linear dilaton (LD) and 5D clockwork models, for which [Formula: see text] TeV. We also analyze a pure (continuum) LD scenario, solving the hierarchy problem with more conventional fundamental [Formula: see text] and [Formula: see text] scales of the order of [Formula: see text], and a continuum spectrum.

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