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arXiv · 1203.1123

Too many $X's$, $Y's$ and $Z's$?

T. F. Caramés·A. Valcarce·J. Vijande
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Abstract

A large number of new states have been reported during the last few years in charmonium spectroscopy above the charmed meson production threshold. They have been called $X's$, $Y's$, and $Z's$. We reflect on the influence of thresholds on heavy meson spectroscopy comparing different flavor sectors and quantum numbers. The validity of a quark-model picture above open-flavor thresholds would severely restrict the number of channels that may lodge meson-meson molecules.

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T. F. Caramés, A. Valcarce, J. Vijande. 2012-03-06. Too many $X's$, $Y's$ and $Z's$?. https://doi.org/10.1016/j.physletb.2012.02.020

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