Dynamics of Non-renormalizable Electroweak Symmetry Breaking (0711.2511v2)

Abstract: We compute the complete one-loop finite temperature effective potential for electroweak symmetry breaking in the Standard Model with a Higgs potential supplemented by higher dimensional operators as generated for instance in composite Higgs and Little Higgs models. We detail the resolution of several issues that arise, such as the cancellation of infrared divergences at higher order and imaginary contributions to the potential. We follow the dynamics of the phase transition, including the nucleation of bubbles and the effects of supercooling. We characterize the region of parameter space consistent with a strong first-order phase transition which may be relevant to electroweak baryogenesis. Finally, we investigate the prospects of present and future gravity wave detectors to see the effects of a strong first-order electroweak phase transition.

• The paper computes the finite temperature effective potential including non-renormalizable operators to analyze electroweak symmetry breaking, finding these operators can enable a strong first-order phase transition.
• The study analyzes the dynamics of the phase transition, including bubble nucleation and supercooling, highlighting how supercooling impacts the transition timing and dynamics relevant for baryogenesis.
• The research explores detecting gravitational waves from the phase transition by calculating parameters that determine the gravity wave spectrum and comparing potential signals with the sensitivity of current and future detectors.

Dynamics of Non-renormalizable Electroweak Symmetry Breaking

The paper "Dynamics of Non-renormalizable Electroweak Symmetry Breaking" focuses on the computation of the one-loop finite temperature effective potential for electroweak symmetry breaking within the framework of the Standard Model (SM) extended by non-renormalizable operators. The paper particularly addresses the electroweak phase transition (EWPT), a crucial aspect for understanding baryogenesis and the generation of matter-antimatter asymmetry in the universe. The analysis is elaborate, accounting for contributions from higher-dimensional operators that are often encountered in scenarios involving composite Higgs and Little Higgs models.

One-Loop Finite Temperature Effective Potential

The paper computes the finite temperature effective potential by including contributions from SM particles and considering higher dimensional operators, primarily focusing on the $H^6$ operators. This allows for exploring dynamics that are not captured by the renormalizable part of the SM. The computation reveals that the presence of these operators can facilitate a strong first-order phase transition, a necessary condition for electroweak baryogenesis. The resolution of the infrared divergences and imaginary contributions to the potential is also detailed. These aspects are handled using a consistent renormalization approach, highlighting the importance of properly accounting for higher-loop corrections and ring diagrams when evaluating the potential at finite temperatures.

Dynamics of the Phase Transition

The dynamics of the phase transition, characterized by phenomena such as bubble nucleation and supercooling, are intricately analyzed. The paper identifies a region in the parameter space where a strong first-order phase transition occurs, which is pertinent for electroweak baryogenesis. Notably, the effects of supercooling—where the universe cools below the critical temperature before bubbles nucleate and grow—are significant. This modification affects the timing and dynamics of the phase transition, which has implications for baryogenesis.

Implications for Gravitational Waves

The paper explores the prospects of detecting gravitational waves emanating from the EWPT. The authors calculate the relevant parameters, such as the latent heat and the duration of the phase transition, which determine the characteristics of gravity wave production. These parameters allow for estimating the gravity wave spectrum, facilitating a comparative analysis with the sensitivity of current and future detectors like LIGO, LISA, and BBO. The possibility of detecting gravitational signatures from the EWPT provides a novel observational pathway to test electroweak theories beyond the SM.

Practical and Theoretical Implications

The insights from this research extend beyond the immediate phenomenological implications. Theoretical models incorporating composite or Little Higgs frameworks stand to benefit significantly, given the paper's detailed analysis of higher dimensional operators and their effects. Practically, advancements in gravitational wave detection could offer an empirical foothold to validate such theoretical extensions.

Future Developments

Looking forward, further exploration into the effective potential’s behavior at multi-loop levels and a more exhaustive examination of new physics scenarios will be vital. Additionally, improving the precision of gravitational wave predictions and enhancing detector capabilities will be crucial for any potential detection of gravitational waves from the EWPT.

In conclusion, the research enriches our understanding of the complex dynamics at play in non-renormalizable extensions of electroweak symmetry breaking, with significant implications for both cosmology and particle physics. This work not only aids in better understanding the nature of the electroweak phase transition but also opens up new avenues for probing the early universe through gravitational wave astronomy.