Searcharxiv⌕ Search
Home/Archive/arXiv

arXiv · 2408.10898

Stability of the Standard Model Vacuum with Vector-Like Leptons: A Critical Examination

Kivanc Y. Cingiloglu·Mariana Frank
View original source ↗Read source document ↗Export metadata ↓

Abstract

The stability of the Standard Model (SM) Higgs vacuum is a long-standing issue in particle physics. The SM Higgs quartic coupling parameter is expected to become negative at high scales, potentially generating an unstable vacuum well before reaching the Planck scale. We investigate whether the introduction of vector-like leptons (VLLs) in six distinct gauge anomaly-independent representations can stabilize the SM vacuum without introducing additional scalar fields. By analyzing the mass spectrum and mixing angles of these VLLs with the SM leptons, we identify conditions under which the Higgs potential remains stable. We demonstrate that there exists a set of allowed but narrowed VLL spectra that can indeed stabilize the SM vacuum. We also study the effect of these VLLs on electroweak precision observables, particularly the oblique parameters S and T to ensure fit within global experimental constraints. Finally, we perform a comprehensive analysis of the parameter space allowed by electroweak precision data and the parameter space required for stability, highlighting cases that accommodate both. This study opens up new avenues for understanding the role of vector-like leptons in extending the validity of the Standard Model up to the Planck scale.

Explore related subjects

hep-ph

Keep this discovery

BibTeXRIS

Kivanc Y. Cingiloglu, Mariana Frank. 2024-08-20. Stability of the Standard Model Vacuum with Vector-Like Leptons: A Critical Examination. https://doi.org/10.1103/physrevd.111.016025

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Axionic Wormholes in Metric-Affine Gravity

The axion is a promising candidate for solving the strong CP problem. To solve this problem, the global U(1) symmetry must be preserved to a high degree of accuracy. However, it is well known that global symmetries are explicitly violated by quantum gravity effects, giving rise to what is referred to as the axion quality problem. In this paper, we investigate axionic wormholes as a source of explicit U(1) violation in Metric-Affine Gravity. This framework allows for spacetime torsion and non-metricity, which accommodate additional curvature-like and topological terms, such as the Holst and Nieh--Yan terms, that are absent from the metric and Palatini formalisms. We show that non-minimal couplings to these terms modify the wormhole dynamics and enhance the Euclidean wormhole action, thereby alleviating the axion quality problem. We also find that the viable parameter space is enlarged when two of these couplings are simultaneously present. We further identify representative parameter regions where the alleviation of the axion quality problem is compatible with inflationary constraints.

hep-ph↗
arXiv2026

Qubit-Qutrit Quantum Tomography of hadronic $\Lambda\phi$ and $\Lambda K^{\ast 0}$ systems

Quantum-information observables have emerged in recent years as new tools in nuclear and particle physics, from entanglement in top-quark pairs to spin correlations in $\Lambda\bar{\Lambda}$ production. Extending these studies to unequal-spin hadronic final states poses a fundamental challenge: the $6\times6$ density matrix of a qubit-qutrit system contains 35 independent spin parameters, but the decays of $\Lambda V$ pairs, with $V=\phi$ or $K^{*0}$, provide access to only 23 due to the hidden vector polarization from the strong decay. In this Letter, we formulate a qubit-qutrit quantum tomography (QQQT) technique for these spin-$\tfrac{1}{2}\otimes1$ systems and establish exact criteria for entanglement certification from the \textit{incomplete} density matrix. Compared with the $\Lambda\bar{\Lambda}$ system, QQQT of $\Lambda\phi$ and $\Lambda K^{*0}$ provides a new probe of nonperturbative QCD hadronization, enabling a direct comparison of the spin evolution of entangled quark pairs produced from the vacuum as they hadronize into a baryon or a vector meson.

hep-ph↗
arXiv2026

Twist decomposition of exclusive heavy meson production cross sections

We study the twist decomposition of the total cross sections for exclusive heavy vector meson electroproduction and photoproduction in the $\gamma^\ast p$ processes, within the leading logarithmic $1/x$ BFKL formalism. The Mellin transforms of the impact factors of the vector meson are calculated. We show that the higher twist contributions are strongly suppressed in the low-$x$ kinematical regime. Possible enhancement of the higher twists effects for nuclei targets is discussed.

hep-ph↗