- The paper demonstrates that tiny black holes can catalyze Higgs vacuum decay by reducing the tunneling action required for bubble nucleation.
- It extends conventional nucleation theory by incorporating gravitational effects and thick-wall bubble dynamics in the metastability framework.
- Numerical results show that enhanced decay rates may necessitate new physics or the absence of primordial black holes in our universe.
The Fate of the Higgs Vacuum: An Analytical and Numerical Exploration
The paper "The Fate of the Higgs Vacuum" by Ruth Gregory and Ian G. Moss addresses an important topic in particle physics: the stability of the Higgs vacuum. This research explores the potential role of tiny black holes in catalyzing the decay of a metastable Higgs vacuum, providing theoretical insights into this phenomenon using both analytical and numerical methods.
Recent discussions in the field have centered on the metastability of the Higgs vacuum. Given the measured mass of the Higgs boson, it suggests that our universe's vacuum is not absolute but metastable. The core question, as posed by the authors, is the lifetime of this metastable state. The probability of transition to true vacuum is exponentially dependent on the action of a Euclidean tunneling solution which measures the likelihood of nucleation.
In their work, Gregory and Moss begin by considering the conventional theory of vacuum decay via bubble nucleation. Typically, it involves the formation of a true vacuum bubble within a false vacuum, where the energy balance dictates the nucleation dynamics. This model is extended to include gravitational effects—a consideration of prime importance considering the Higgs vacuum structure involves gravity, as proposed decades ago by Coleman and collaborators.
The novel aspect of this paper is the introduction of black holes as nucleation sites. The presence of a black hole can significantly lower the action required for vacuum decay, thus enhancing the decay probability. Specifically, the authors explore the decoherence effects of a Euclidean tunneling solution modulated by a black hole, demonstrating that even minute black holes can dramatically influence vacuum stability, challenging previous postulations relying solely on cosmic homogeneity.
The paper provides strong numerical support showing that bubble nucleation rates can be drastically heightened when thick-wall bubbles, rather than thin-wall assumptions, are considered. The results imply that either small black holes do not naturally exist as a component of our universe or that beyond Standard Model (BSM) corrections are necessary to stabilize the Higgs potential to prevent decay into a lower energy state.
The numerical results highlight a significant enhancement of vacuum decay rates that far exceed those predicted by conventional models without black holes. This enhancement suggests that even in cases where Hawking radiation is expected to be the dominant decay channel for small black holes, vacuum decay can prevail, effectively outpacing Hawking evaporation and leading to possible catastrophic consequences for our universe.
The authors speculate on the future implications of this research, suggesting that if small primordial black holes exist, they could trigger a transition to a universe with different physical constants and laws—a scenario that runs contrary to current observational data. The absence of such black holes or a requisite adjustment to the Higgs potential through unknown BSM physics implies an area ripe for exploration, possibly directing future collider experiments or observational cosmology to address these concerns.
In conclusion, Gregory and Moss's work provides a rigorous theoretical framework bolstered by numerical analysis that challenges the stability assumptions of the Higgs vacuum. This research sets the stage for deeper investigations into the quantum gravitational corrections to the Higgs potential, paving the way for new discoveries in particle physics and cosmology.