Strong decays of the lowest bottomonium hybrid within an extended Born-Oppenheimer framework

TL;DR

This paper develops a QCD-motivated framework to analyze the decay properties of the lowest bottomonium hybrid, revealing potential experimental evidence for its existence through decay width comparisons and mixing with known states.

Contribution

It introduces a new decay model for bottomonium hybrids within an extended Born-Oppenheimer framework, linking hybrid and bottomonium decay descriptions and analyzing their experimental implications.

Findings

H(1P) and $mbda(5S)$ have very different decay widths.

Neither pure $mbda(5S)$ nor $H(1P)$ explains the decay data.

Possible $mbda(5S)$-$H(1P)$ mixing could account for observed decay widths.

Abstract

We analyze the decays of the theoretically predicted lowest bottomonium hybrid $H(1P)$ to open bottom two-meson states. We do it by embedding a quark pair creation model into the Born-Oppenheimer framework which allows for a unified, QCD-motivated description of bottomonium hybrids as well as bottomonium. A new $^{1}\!P_{1}$ decay model for $H(1P)$ comes out. The same analysis applied to bottomonium leads naturally to the well-known $^{3}\!P_{0}$ decay model. We show that $H(1P)$ and the theoretically predicted bottomonium state $\Upsilon(5S)$, whose calculated masses are close to each other, have very different widths for such decays. A comparison with data from $\Upsilon(10860)$, an experimental resonance whose mass is similar to that of $\Upsilon(5S)$ and $H(1P)$, is carried out. Neither a $\Upsilon(5S)$ nor a $H(1P)$ assignment can explain the measured decay widths. However, a $\Upsilon(5S)$-$H(1P)$ mixing may give account of them supporting previous analyses of dipion decays of $\Upsilon(10860)$ and suggesting a possible experimental evidence of $H(1P)$.