Tests of the nature and of the gluon content of the σ(0.6) from D and D_{s} semileptonic decays
Abstract
Description
We summarize the different features which show that QCD spectral sum rule analyses of the scalar two- and three-point functions do not favour the $\bar uu+\bar dd$ interpretation of the broad and low mass $σ(0.6)$ and emphasize that a measurement of the $D_s$ semileptonic decays into $ππ$ can reveal in a model-independent way its eventual gluon component $σ_B$. The analysis also implies that one expects an observation of the $K\bar K$ final states from the $σ_B$ which may compete (if phase space allowed) with the one from a low mass $\bar ss$ state assumed in the literature to be the SU(3) partner of the observed $σ(0.6)$ if the latter is a $\bar uu+\bar dd$ state
6 pages latex file. 4 fig.eps
6 pages latex file. 4 fig.eps