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Large Two-Loop Contributions to g-2 from a Generic Pseudoscalar Boson

Darwin Chang·We-Fu Chang·Chung-Hsien Chou·Wai-Yee Keung
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Abstract

We calculate the dominant contributions to the muon $g-2$ at the two-loop level due to a generic pseudoscalar boson that may exist in any exotic Higgs sector in most extensions of the standard model. The leading effect comes from diagrams of the Barr-Zee type. A sufficiently light pseudoscalar Higgs boson can give rise to contribution as large as the electroweak contribution which is measurable in the next round of $g-2$ experiment. Through the contribution we calculated here, the anticipated improved data in the recent future on the muon $g-2$ can put the best limit on the possible existence of a light pseudoscalar boson in physics beyond the standard model.

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Darwin Chang, We-Fu Chang, Chung-Hsien Chou, Wai-Yee Keung. 2001-03-16. Large Two-Loop Contributions to g-2 from a Generic Pseudoscalar Boson. https://doi.org/10.1103/physrevd.63.091301

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