E-Thesis 261 views 308 downloads
First-order deconfining phase transitions in Yang-Mills theories / DAVID MASON
Swansea University Author: DAVID MASON
DOI (Published version): 10.23889/SUThesis.69934
Abstract
Finite temperature first-order deconfinement phase transitions of non-Abelian gauge theory systems can lead to rich phenomenological implications to the cosmological evolution of the early universe, resulting in potentially observable imprints on the current universe such as the matter anti-matter asy...
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Swansea University, Wales, UK
2024
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| Institution: | Swansea University |
| Degree level: | Doctoral |
| Degree name: | Ph.D |
| Supervisor: | Lucini, B, and Piai, M |
| URI: | https://cronfa.swan.ac.uk/Record/cronfa69934 |
| Abstract: |
Finite temperature first-order deconfinement phase transitions of non-Abelian gauge theory systems can lead to rich phenomenological implications to the cosmological evolution of the early universe, resulting in potentially observable imprints on the current universe such as the matter anti-matter asymmetry and a background of gravitational waves. It is generally accepted that deconfinement in standard model of particle physics arises through a cross-over and therefore the system transitions from one regime to the other without producing non-equilibrium effects. However, it is also widely acknowledged that the standard model is not the full picture in particle physics, since, for instance, to explain problems such as the existence of dark matter, we require new physics. A large array of extensions of the standard model are based on the addition of a new strongly interacting sector, with a new set of non-Abelian gauge fields. This new sector might undergo a first order deconfinement phase transition whose observable effects can in principle be detectable. This thesis develops a methodology for precision studies of these phase transitions considering the be-yond the standard model theory – and in particular its gauge sector - in isolation. As the confining properties of the model are inherently non-perturbative we choose to analyse it numerically using lattice field theory. However, the meta-stable dynamics characteristic of a first-order phase transition can lead to intractable problems with standard importance sampling methods. We resolve this issue through the use of the Logarithmic Linear Relaxation (LLR) method, which samples a flat energy distribution to accurately compute the density of states. Through the density of states, we can reconstruct observables, compute the energy distribution and determine thermodynamic properties, such as the free-energy, that are out of reach with importance sampling methods. This work develops a density of state approach based on the LLR method and tests in SU(3) and Sp(4) gauge theories, for which a highly accurate set of results for thermodynamic observables is obtained. |
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| Keywords: |
Lattice Field Theory, Thermodynamics, Particle Physics, Beyond the Standard Model, Phase transitions, |
| College: |
Faculty of Science and Engineering |
| Funders: |
Data Intensive Centre for Doctoral Training |