  In this paper, we are concerned with the Cauchy problem and wave-breaking
phenomenon for a sine-type modified Camassa-Holm (alias sine-FORQ/mCH)
equation. Employing the transport equations theory and the Littlewood-Paley
theory, we first establish the local well-posedness for the strong solutions of
the sine-FORQ/mCH equation in Besov spaces. In light of the Moser-type
estimates, we are able to derive the blow-up criterion and the precise blow-up
quantity of this equation in Sobolev spaces. We then give a sufficient
condition with respect to the initial data to ensure the occurance of the
wave-breaking phenomenon by trace the precise blow-up quantity along the
characteristics associated with this equation.
