Model for anomalous ${{\rm Y}}^{\prime \prime }\to {\rm Y}\pi \pi$ transition with account of chiral phase shift in hadron bag of quarkonium

Abstract

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

Comments: 20 pages, IHEP 94-46, Protvino, Russia