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arXiv · 2005.06455

Semileptonic decays $D\toπ^+π^-e^+ν_e$ and $D_s\toπ^+π^-e^+ν_e$ as the probe of constituent quark-antiquark pairs in the light scalar mesons

N. N. Achasov·A. V. Kiselev·G. N. Shestakov
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Abstract

Decays $D\toπ^+π^-e^+ν_e$ and $D_s\toπ^+ π^-e^+ν_e$ serve as probes that check the existence of constituent $q\bar q$ components in the wave functions of scalar mesons decaying into $π^+π^-$. 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 $q^2\bar q^2$ model validity for light scalars on ever new processes seems extremely interesting and important. We analyze the BESIII and CLEO data on the decays $D^+\to π^+π^- e^+ν_e$ and $D^+_s\to π^+π^- e^+ν_e$ and show that the results of these experiments together can be interpreted in favor of the four-quark nature of light scalar mesons $σ(500)$ and $f_0(980)$. Our approach can also be applied to the description of other similar decays involving light scalars.

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N. N. Achasov, A. V. Kiselev, G. N. Shestakov. 2020-07-28. Semileptonic decays $D\toπ^+π^-e^+ν_e$ and $D_s\toπ^+π^-e^+ν_e$ as the probe of constituent quark-antiquark pairs in the light scalar mesons. https://doi.org/10.1103/physrevd.102.016022

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