Electroweak phase transitions
An analytic treatment of the one Higgs doublet, electroweak phase transition is given. The phase transition is first order, occurs by the nucleation of thin walled bubbles, and completes at a temperature where the order parameter, [[phi]][sub T], is significantly smaller than it is when the origin becomes absolutely unstable. The rate of anomalous baryon number violation is an exponentially sensitive function of [[phi]][sub T]. In very minimal extensions of the standard model it is easy to increase [[phi]][sub T] so that anomalous baryon number violation is suppressed after completion of the phase transition. Baryogenesis at the electroweak phase transition is tenable in minimal extensions of the standard model. In some cases additional phase transitions are possible. For a light Higgs boson, when the top quark mass is sufficiently large, the state where the Higgs field has a vacuum expectation value [[phi]] = 246 GeV is not the true minimum of the Higgs potential. When this is the case, and when the top quark mass exceeds some critical value, thermal fluctuations in the early universe would have rendered the state [[phi]] = 246 GeV unstable. The requirement that the state [[phi]] = 246 GeV is sufficiently long lived constrains the masses of the Higgs boson and the top quark. Finally, the author considers whether local phase transitions can be induced by heavy particles which act as seeds for deformations in the scalar field. Semi-classical reasoning suggests that, when a particle receives a contribution to its mass from the vacuum expectation value of a scalar, under certain conditions, the ground state of particle number one contains a [open quotes]dimple[close quotes] or shallow scalar field condensate around the particle. It is argued that this is not the case. A careful analysis shows that the semi-classical approximation is a poor one. It is found that there are no energetically favored one-particle dimple solutions for perturbative couplings.
- Research Organization:
- California Univ., Berkeley, CA (United States)
- OSTI ID:
- 7112596
- Resource Relation:
- Other Information: Thesis (Ph.D.)
- Country of Publication:
- United States
- Language:
- English
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STANDARD MODEL
MODIFICATIONS
WEINBERG-SALAM GAUGE MODEL
PHASE TRANSFORMATIONS
HIGGS BOSONS
TOP PARTICLES
WEAK INTERACTIONS
BASIC INTERACTIONS
ELEMENTARY PARTICLES
FIELD THEORIES
INTERACTIONS
MATHEMATICAL MODELS
PARTICLE MODELS
POSTULATED PARTICLES
UNIFIED GAUGE MODELS
UNIFIED-FIELD THEORIES
662210* - Specific Theories & Interaction Models
Particle Systematics- Unified Theories & Models- (1992-)