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arXiv · 1901.05626

Vector-like Quark Interpretation of Excess in Higgs Signal Strength

Kingman Cheung·Wai-Yee Keung·Jae Sik Lee·Po-Yan Tseng
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Abstract

There is a $+2σ$ deviation in the average Higgs-signal strength for all the $7+8+13$ TeV data up to Summer 2018. We find that a slight reduction of the bottom-Yukawa coupling can fit the data better than the standard model. We suggest an extension with a vector-like quark doublet, of which the right-handed component of $b'$ mixes nonnegligibly with the standard model $b$ quark. We show that the mixing would induce a reduction of the bottom Yukawa coupling. Simultaneously, the coupling of the $Z$ boson to the right-handed $b$ quark increases, which could reduce the forward-backward asymmetry of bottom production at LEP and bring it closer to the experimental value.

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Kingman Cheung, Wai-Yee Keung, Jae Sik Lee, Po-Yan Tseng. 2019-01-17. Vector-like Quark Interpretation of Excess in Higgs Signal Strength. https://doi.org/10.1016/j.physletb.2019.134983

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