Enhanced mixing of partial waves near threshold for heavy meson pairs and properties of $Z_b(10610)$ and $Z_b(10650)$ resonances

Abstract

The mixing of $S-D$ partial waves for the heavy meson pairs in the decays ${\rm Y}(5S)\to [B^{\ast }\bar{B}+c.c.]\pi$ and ${\rm Y}(5S)\to B^{\ast }{\bar{B}}^{\ast }\pi$ is considered. It is argued that this mixing, enhanced by the heavy meson mass, is calculable as dominated by a rescattering through pion exchange if the production of the heavy mesons is dominated by $S$-wave `molecular' resonances $Z_b(10610)$ and $Z_b(10650)$. The effect of the mixing grows with the c.m. energy $E$ in each channel over the threshold, and may reach $10÷20$% in the rate at the upper end of applicability of the discussed approach, $E\sim 15$MeV. It is also argued that the mixing is likely to reach maximum at energy approximately equal to the mass gap between the thresholds.

8 pages, 3 figures

References in corpus (1)

• Study of Three-Body Y(10860) Decays

Cited by in corpus (9)

• Confirming the molecular nature of the $Z_b(10610)$ and the $Z_b(10650)$
• More hidden heavy quarkonium molecules and their discovery decay modes
• Enhanced breaking of heavy quark spin symmetry
• Hunting for the $X_b$ via hidden bottomonium decays
• Weak Decays of Triply Heavy Tetraquarks $b\bar{c}b\bar{q}$
• Exploring the ${\rm Y}(4S,5S,6S)\to h_b(1P)\eta$ hidden-bottom hadronic transitions
• $D$ wave bottomonia production from $Z_b^{(\prime )}$ decay
• Evasion of HSR in the charmless decays of excited $P$-wave charmonia
• Decays of ${\rm Y}(10860)$ and ${\rm Y}(10753)$ into $\omega {\chi }_{bJ}$