Semileptonic decays D→π+π−e+νe and Ds

Abstract

Decays D → π þ π − e þ ν e and D s → π þ π − e þ ν e serve as probes that check the existence of constituent qq components in the wave functions of scalar mesons decaying into π þ π −. There exists a great deal of concrete evidence in favor of the exotic four-quark nature of light scalars. At the same time, the further expansion of the area of the q 2q2 model validity for light scalars on ever new processes seems extremely interesting and important. We analyze the BESIII and CLEO data on the decays D þ → π þ π − e þ ν e and D þ s → π þ π − e þ ν e and show that the results of these experiments together can be interpreted in favor of the four-quark nature of light scalar mesons σð500Þ and f 0 ð980Þ. Our approach can also be applied to the description of other similar decays involving light scalars.