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We present an analysis of strong two-body decays of the $a_1(1420)$ with$J^{PC} = 1^{++}$ recently reported by the COMPASS Collaboration at CERN.Following the interpretation of the COMPASS Collaboration that the $a_1$ is anunusual state with a four-quark $q\bar q s \bar s$ structure we consider twopossible configurations for this state --- hadronic molecular and colordiquark-antidiquark structures. We find that the dominant decay mode of the$a_1$ is the decay into $K$ and $K^*$. In particular, we calculate that thefour decay modes $a_1 \to VP$ with $VP = K^{*\pm}K^\mp$, $K^{*0}\bar K^0$,$\bar K^{*0}K^0$ together give a dominant contribution to the measured totalwidth of about 150 MeV. The observational mode $a_1 \to f_0(980) + \pi^0$ issignificantly suppressed by one order of magnitude.

Test of the multiquark structure of $a_1(1420)$ in strong two-body decays