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Large effects on $\BsBs$ mixing by vector-like quarks

Mayumi Aoki·Gi-Chol Cho·Makiko Nagashima·Noriyuki Oshimo
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Abstract

We calculate the contributions of the vector-like quark model to $\BsBs$ mixing, taking into account the constraints from the decay $B\to X_sγ$. In this model the neutral bosons mediate flavor-changing interactions at the tree level. However, $\BsBs$ mixing is dominated by contributions from the box diagrams with the top quark and the extra up-type quark. In sizable ranges of the model parameters, the mixing parameter $x_s$ is much different from the standard model prediction.

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Mayumi Aoki, Gi-Chol Cho, Makiko Nagashima, Noriyuki Oshimo. 2001-11-26. Large effects on $\BsBs$ mixing by vector-like quarks. https://doi.org/10.1103/physrevd.64.117305

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