  Experiments on a thin layer of cohesive wet granular matter under vertical
vibrations reveal kink separated domains that collide with the container at
different phases. Due to the strong cohesion arising from the formation of
liquid bridges between adjacent particles, the domains move collectively upon
vibrations. Depending on the periodicity of this collective motion, the kink
fronts may propagate, couple with each other and form rotating spiral patterns
in the case of period tripling, or stay as standing wave patterns in the case
of period doubling. Moreover, both patterns may coexist with granular `gas
bubbles' - phase separation into a liquidlike and a gaslike state. Stability
diagrams for the instabilities measured with various granular layer mass $m$
and container height $H$ are presented. The onsets for both types of patterns
and their dependency on $m$ and $H$ can be quantitatively captured with a model
considering the granular layer as a single particle colliding completely
inelastically with the container.
