Abstract
The attractive interaction between
and
has to be strong enough if X(6900) is of the molecule type. We argue that since
decays predominantly into a
pair, the interactions between
and
may be significantly enhanced owing to the three point
loop diagram. The enhancement originates from the anomalous threshold located at
GeV
, whose effect propagates into the s-channel partial wave amplitude in the vicinity of
GeV. This effect may be helpful in the formation of the
peak.
