2007 Fiscal Year Final Research Report Summary
Unification of Forces in Gauge Theory and Gravity
| Project/Area Number |
17540257
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Particle/Nuclear/Cosmic ray/Astro physics
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| Research Institution | Osaka University |
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Principal Investigator |
HOSOTANI Yutaka Osaka University, Graduate School of Science, Professor (50324744)
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| Project Period (FY) |
2005 – 2007
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| Keywords | Particle Physics / Hither dimensional gauge theory / Hosotani mechanism / gauge-Higgs unification / Extra dimensions |
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| Research Abstract |
In 1983 Hosotani proposed a scenario called the Hosotani mechanism in which gauge fields and Higgs fields are unified in higher dimensional gauge theory and gauge symmetry is dynamically broken by quantum effects. This mechanism is applied to electroweak interactions to show how to check and verify the scenario in experiments at LHC. The 4D Higgs field becomes a part of gauge fields, its interactions being governed and dictated by the gauge principle. There was difficulty in gauge-Higgs unification in flat space that both the mass of the Higgs particle and the Kaluza-Klein mass scale become too small. Hosotani pointed out that this difficulty is solved in the gauge-Higgs unification scenario in the Randall-Sundrum (RS) warped space. In the RS space the Higgs mass is predicted in a range 120 GeV - 290 GeV, and the Kaluza-Klein scale in a range 1.5 TeV - 3.5 TeV. In the SO (5) x U (1) model there appear deviation from the standard model in the Higgs couplings to W and Z bosons by a universal factor cos (theta_H) where theta_H is an AB phase characterizing the Hosotani mechanism. This suppression can be tested at LHC. A similar suppression occurs for Yukawa couplings of fermions.
It has been known that the mass of a Higgs particle is finite in the gauge-Higgs unification scenario at the one loop level. It is shown that this property generalizes to the two loop level in QED when the fifth dimension is a circle. This fact implies that even though higher dimensional gauge theory is not renormalizable, it is possible to make a definitive, meaningful prediction for the mass of the Higgs particle.
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Research Products
(57 results)
