| DATE: |
2009-05-19 11:00 - |
| PLACE: |
Kenkyu Honkan 2F RM 220 |
| TITLE: |
The strongly coupled fourth family and a first-order electroweak phase transition |
| CONTACT: |
SAKURAI, Kazuki/sakurai AT post.kek.jp |
| SPEAKER: |
Dr. Masaya Kohda (Saitama University) |
| LANGUAGE: |
English |
| ABSTRACT: |
We discuss a finite-temperature electroweak phase transition in models of dynamical electroweak symmetry breaking due to strongly coupled fourth-family fermions from the point of view of the electroweak baryogenesis. Based on the low-energy renormalizable effective theory, which consists of the fourth-family quarks and two SU(2)-doublet composite Higgs fields, we examine a possibility that the electroweak phase transition is strongly first order. Through the analysis of the finite-temperature effective potential at one loop with ring improvement, we found that the strongly first-order phase transition is possible even if the mass of the neutral scalar Higgs is larger than 114 GeV. It is also found that the requirements of the strongly first-order phase transition as well as the renormalizability lead to the fourth-family quark masses being smaller than about 300 GeV.
Referenceˇ§ arXiv:0901.1962 [hep-ph] |
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