Options for the SELEX state D$_{s\J}^+(2632)$

Abstract

We consider possible assignments for the D$_{s\J}^+(2632)$, which was recently reported in D$_s^+η$ and D$^0$K$^+$ final states by the SELEX Collaboration at Fermilab. The most plausible quark model assignment for this state is the first radial excitation ($2^3§_1$) of the $c\bar s$ D$_s^*(2112)$, although the predicted mass and strong decay branching fractions for this assignment are not in agreement with the SELEX data. The reported dominance of D$_sη$ over DK appears especially problematic. An intriguing similarity to the K$^*(1414)$ is noted. $2^3§_1$--$^3\D_1$ configuration mixing is also considered, and we find that this effect is unlikely to resolve the branching fraction discrepancy. Other interpretations as a $c\bar s$-hybrid or a two-meson molecule are also considered, but appear unlikely. Thus, if this state is confirmed, it will require reconsideration of the systematics of charmed meson spectroscopy and strong decays.