  In the testable Flipped $SU(5)\times U(1)_X$ model with TeV-scale vector-like
particles from F-theory model building dubbed as the flip SU(5) model, we study
the vector-like quark contributions to B physics processes, including the quark
mass spectra, Feynman rules, new operators and Wilson coefficients, etc. We
focus on the implications of the vector-like quark mass scale on B physics. We
find that there exists the $\bar{s}bZ$ interaction at tree level, and the
Yukawa interactions are changed. Interestingly, different from many previous
models, the effects of vector-like quarks on rare B decays such as $B\to
X_s\gamma$ and $B\to X_s\ell^+\ell^-$ do not decouple in some viable parameter
space, especially when the vector-like quark masses are comparable to the
charged Higgs boson mass. Under the constraints from $B\to X_s\gamma$ and $\
B\to X_s\ell^+\ell^-$, the latest measurement for $B_s\to \mu^+\mu^-$ can be
explained naturally, and the branching ratio of $B_s\to \ell^+\ell^-\gamma$ can
be up to $(4\sim5)\times10^{-8}$. The non-decouling effects are much more
predictable and thus the \fsu5 model may be tested in the near future
experiments.

High Energy Physics - Phenomenology