Simple Science

Cutting edge science explained simply

# Physics# High Energy Physics - Phenomenology

Little Higgs Models and Conformal Symmetry

A fresh approach to the hierarchy problem in particle physics.

― 4 min read


Conformal Little HiggsConformal Little HiggsInsightsproblem in particle physics.Exploring solutions to the hierarchy
Table of Contents

Little Higgs models are theoretical constructs in particle physics. They aim to tackle a major problem known as the Hierarchy Problem. This problem arises due to the large difference between the gravitational scale and the energy scale of electroweak Interactions. In simpler terms, it questions why the Higgs boson, which gives mass to particles, does not have an extremely high mass compared to other particles.

In these models, the Higgs boson is not viewed as a fundamental particle. Instead, it is considered as a composite object made up of more basic components. This approach can help reduce the sensitivity of the Higgs mass to high-energy processes, which is a key point in addressing the hierarchy problem.

The Importance of UV Completion

Most Little Higgs models operate below a certain energy level, often up to a few TeV. However, they need a consistent framework that works at higher energy levels, known as ultraviolet (UV) completion. This means that these models should not only work well at lower energies but should also be compatible with theories that describe fundamental interactions at high energies.

One promising direction involves combining Little Higgs models with conformal field theories (CFT). In CFT, scale and symmetry play a big role, allowing the emergence of mass and energy scales from the underlying dynamics without requiring additional parameters to be introduced manually.

Conformal Symmetry

Conformal symmetry is a type of symmetry that remains intact under certain transformations, such as scaling. In the context of particle physics, having a theory that exhibits conformal symmetry simplifies the understanding of particle interactions and scales.

In conformal Little Higgs models, the idea is that not all particles have to be treated as fundamental. Instead, they can emerge from interactions and symmetries dynamically, thereby providing a more robust explanation for masses and interactions.

Challenges and Solutions

One of the main challenges in combining Little Higgs models with conformal symmetry is ensuring that the theory does not have issues known as conformal anomalies. These anomalies can arise due to quantum effects, potentially undermining the benefits of having conformal symmetry.

To maintain conformal dynamics, it is crucial to ensure that all interactions have fixed points in the UV limit. This means that the behavior of the interactions should be predictable at high energies without needing fine-tuning of parameters.

A New Framework for Little Higgs Models

Recent developments propose a unified framework that combines the principles of Little Higgs models and conformal symmetry. This novel approach allows for a consistent treatment of the hierarchy problem while providing a natural handling of the flavor issues associated with these models.

In this framework, particle interactions can exhibit both strong and weak behaviors, depending on the energy scale. The importance of strong interactions is particularly notable as they can lead to the formation of composite states, which can explain the properties of the Higgs boson and other particles.

Implications for Particle Physics

By leveraging conformal dynamics, this new framework can naturally decouple flavor scales from the electroweak scale. This decoupling is significant because it helps separate the high-energy dynamics from the low-energy phenomenology typically observed in particle physics. It means that aspects of Flavor Physics, which deals with the differences in mass and charge between different types of particles, do not interfere with the fundamental mechanics of mass generation.

This separation can lead to more precise predictions regarding the behavior of particles in high-energy collisions, such as those performed in particle accelerators like the Large Hadron Collider (LHC).

Predictions and Future Studies

The proposed conformal Little Higgs models lead to several key predictions regarding particle behavior. For instance, the model anticipates the presence of broad resonances and continuum states linked to strong conformal dynamics. These predictions provide a pathway for experimental verification, as they suggest that specific signatures could emerge during high-energy collisions.

Future collider experiments could potentially observe these features and provide insights into the underlying dynamics of the conformal Little Higgs model. This would not only enhance our understanding of particle masses and interactions but also deepen our overall comprehension of fundamental physics.

Conclusion

Little Higgs models represent an exciting avenue for addressing fundamental questions in particle physics. By integrating conformal symmetry into these models, researchers aim to provide a consistent explanation for the hierarchy problem while ensuring that the theory remains valid across a broad range of energy scales.

The exploration of this new framework offers a rich area for theoretical and experimental investigation, with the potential for groundbreaking discoveries in our understanding of the universe at the smallest scales. As experimental possibilities expand, the implications of conformal Little Higgs models will become increasingly relevant, potentially reshaping our understanding of the fundamental forces and particles that govern the universe.

Original Source

Title: Conformal little Higgs models

Abstract: Little Higgs models address the hierarchy problem by identifying the SM Higgs doublet as pseudo-Nambu--Goldstone bosons (pNGB) arising from global symmetries with collective breakings. These models are designed to address the little hierarchy problem up to a scale of $\Lambda\!\sim\! {\cal O}(10)$ TeV. Consequently, these models necessitate an ultraviolet (UV) completion above this scale. On the other hand, conformal extensions of the Standard Model are intriguing because scales emerge as a consequence of dimensional transmutation. In this study, we present a unified framework in which the electroweak hierarchy problem is tackled through a conformal symmetry collectively broken around the TeV scale, offering an appealing UV completion for little Higgs models. Notably, this framework automatically ensures the presence of the required UV fixed points, eliminating the need for careful adjustments to the particle content of the theory. Moreover, this framework naturally addresses the flavor puzzles associated with composite or little Higgs models. Furthermore, we suggest that in this framework all known little Higgs models can be UV-completed through conformal dynamics above the scale $\Lambda$ up to arbitrary high scales.

Authors: Aqeel Ahmed, Manfred Lindner, Philipp Saake

Last Update: 2024-05-09 00:00:00

Language: English

Source URL: https://arxiv.org/abs/2309.07845

Source PDF: https://arxiv.org/pdf/2309.07845

Licence: https://creativecommons.org/licenses/by/4.0/

Changes: This summary was created with assistance from AI and may have inaccuracies. For accurate information, please refer to the original source documents linked here.

Thank you to arxiv for use of its open access interoperability.

More from authors

Similar Articles