Observation of a Narrow Meson Decaying to D{sub s}{sup +} {pi}{sup 0} at a Mass of 2.32 GeV/c{sup 2}

Abstract

We have observed a narrow state near 2.32 GeV/c{sup 2} in the inclusive D{sub s}{sup +} {pi}{sup 0} invariant mass distribution from e{sup +}e{sup -} annihilation data at energies near 10.6 GeV. The observed width is consistent with the experimental resolution. The small intrinsic width and the quantum numbers of the final state indicate that the decay violates isospin conservation. The state has natural spin-parity and the low mass suggests a J{sup P} = 0{sup +} assignment. The data sample corresponds to an integrated luminosity of 91 fb{sup -1} recorded by the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} storage ring.