  Multi-quark states were predicted by Gell-Mann when the quark model was first
formulated. Recently, numerous exotic states that are considered to be
multi-quark states have been experimentally confirmed (four-quark mesons and
five-quark baryons). Theoretical research indicates that the four-quark state
might comprise molecular and/or tetraquark structures. We consider that the
meson containing four different flavors $su\bar b\bar d$ should exist and decay
via the $X(5568)\to B_s\pi$ channel. However, except for the D0 collaboration,
all other experimental collaborations have reported negative observations for
$X(5568)$ in this golden portal. This contradiction has stimulated the interest
of both theorists and experimentalists. To address this discrepancy, we propose
that the assumed $X(5568)$ is a mixture of a molecular state and tetraquark,
which contributes destructively to $X(5568)\to B_s\pi$. The cancellation may be
accidental and it should be incomplete. In this scenario, there should be two
physical states with the same flavor ingredients, with spectra of $5344\pm307$
and $6318\pm315$. $X(5568)$ lies in the error range of the first state. We
predict the width of the second state (designated as $S_2$) as
$\Gamma(X_{S_2}\to B_s\pi)=224\pm97$ MeV. We strongly suggest searching for it
in future experiments.
