Does zero temperature decide on the nature of the electroweak phase transition?

• Published in: The journal of high energy physics Vol. 2016; no. 6; pp. 1 - 35
• Main Authors: Harman, Christopher P.D., Huber, Stephan J.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-06-2016; Springer Nature B.V
• Subjects: Breaking down; Classical and Quantum Gravitation; Correlation; Elementary Particles; High energy physics; Mathematical analysis; Mathematical models; Phase transformations; Phenomenology; Physics; Physics and Astronomy; Quantum Field Theories; Quantum Field Theory; Quantum Physics; Regular Article - Theoretical Physics; Relativity Theory; Scalars; String Theory; Symmetry; Beyond Standard Model; Higgs Physics; Thermal Field Theory
• ISSN: 1029-8479
• DOI: 10.1007/JHEP06(2016)005

A
bstract
Taking on a new perspective of the electroweak phase transition, we investigate in detail the role played by the depth of the electroweak minimum (“vacuum energy difference”). We find a strong correlation between the vacuum energy difference and the strength of the phase transition. This correlation only breaks down if a negative eigen-value develops upon thermal corrections in the squared scalar mass matrix in the broken vacuum before the critical temperature. As a result the scalar fields slide across field space toward the symmetric vacuum, often causing a significantly weakened phase transition. Phenomenological constraints are found to strongly disfavour such sliding scalar scenarios. For several popular models, we suggest numerical bounds that guarantee a strong first order electroweak phase transition. The zero temperature phenomenology can then be studied in these parameter regions without the need for any finite temperature calculations. For almost all non-supersymmetric models with phenomenologically viable parameter points, we find a strong phase transition is guaranteed if the vacuum energy difference is greater than −8.8 × 10
7
GeV
4
. For the GNMSSM, we guarantee a strong phase transition for phenomenologically viable parameter points if the vacuum energy difference is greater than −6.9×10
7
GeV
4
. Alternatively, we capture more of the parameter space exhibiting a strong phase transition if we impose a simultaneous bound on the vacuum energy difference and the singlet mass.