2007 Fiscal Year Final Research Report Summary
Dynamics of nou-Iinear Sigma models and their application to the little Higgs models
| Project/Area Number |
16540226
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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 | Nagoya University (2007)
Tohoku University (2004-2006) |
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Principal Investigator |
TANABASHI Masaharu Nagoya University, Department of Physirs, Professor (00270398)
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| Project Period (FY) |
2004 – 2007
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| Keywords | beyond-the-standard-models / non-linear sigma models / electroweak precision measurements / chiral perturbation / deconstruction / Higgsless models / unitarity |
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| Research Abstract |
It is widely believed that certain "physics beyond the standard modal" should exist above the TeV scale. These beyond the-standard models(BSM)include various Technicolor models and supeisymmetric model Among them, QCD-lice Technicolor models have been ruled out almost completely by precision measurements of W and Z bosons at LET and Tevatron. Also, we have never observed SUSY partner particles as predicted in SUSY models.
Recently, new type of ESM, such as the lithe Higgs models and the deconstructed Higgsless models, has been proposed. There models ale based on the non-linear sigma models, and are thus non-renormalizable. It is therefore quite difficult to analyze these modals including their radiative corrections.
In this study, from a viewpoint of chiral perturbation theory, we performed a comprehensive analysis on these BSM non-linear sigma models For Higgsless models, we lurid that 1) in any unitary theory, Higgsless models with localized fermion am disfavored by precision electroweak data, 2) it is possible to construct phenomenologically viable Higgsless models once we allow the fermion delocalization, 3) assuming ideal fermion delocalization" deviations in electroweak precision parameters axe minimized, 4) the current constraint on these “ideal fermion delocalization" Higgsless models comes from the measurement of the triple gauge boson vertices We also perfumed a systematic next order evaluation in the chiral perturbation analysis including the radiative corrections in these models.
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