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arXiv · 0707.2323

Violation of the Appelquist-Carazzone decoupling in non-SUSY GUT

Piotr H. Chankowski·Jakub Wagner
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Abstract

We point out that in non supersymmetric GUTs, in which the SU(5) gauge symmetry is broken down to the Standard Model gauge group by a $\mathbf{24}$ Higgs multiplet the Appelquist-Carazzone decoupling is violated. This is because the $SU(2)_L$ Higgs triplet contained in the $\mathbf{24}$ acquires a dimensionfull coupling to the $SU(2)_L$ Higgs doublets which is proportional to the GUT breaking vacuum expectation value (VEV) $V$. As a result, at one loop heavy gauge and Higgs fields contribution to tadpoles generate a VEV of the triplet which is not suppressed for $V\to\infty$ and violates the custodial symmetry.

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Piotr H. Chankowski, Jakub Wagner. 2007-07-16. Violation of the Appelquist-Carazzone decoupling in non-SUSY GUT. https://doi.org/10.1103/physrevd.77.025033

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