Model for anomalous $Υ'' \to Υππ$ transition with account of chiral phase shift in hadron bag of quarkonium

Abstract

We assume that a rather large bag of the $Υ''(3S b\bar b)$ heavy quarkonium is in the phase of spontaneously broken chiral symmetry, in contrast to the $Υ(1S b \bar b)$ hadron bag, having small size and being in the phase of exact chiral symmetry, so that the shift of the phases in the $Υ'' \to Υππ$ transition is the additional source for the $ππ$ pairs. This source causes an anomalous $ππ$ invariant mass distribution, which is experimentally observed.