Newly observed <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msub><mml:mi>a</mml:mi><mml:mn>0</mml:mn></mml:msub><mml:mo stretchy="false">(</mml:mo><mml:mn>1817</mml:mn><mml:mo stretchy="false">)</mml:mo></mml:math> as the scaling point of constructing the scalar meson spectroscopy
Dan Guo, Wei Chen, Hua-Xing Chen, Xiang Liu, Shi-Lin Zhu
Abstract
Stimulated by the newly observed ${a}_{0}(1817)$ by the BESIII Collaboration, we find a perfect Regge trajectory composed of the ${a}_{0}(980)$, ${a}_{0}(1450)$, and ${a}_{0}(1817)$, which leads us to categorize the ${a}_{0}(980)$, ${a}_{0}(1450)$, and ${a}_{0}(1817)$ into the isovector scalar meson family. This scenario is supported by their two-body Okubo-Zweig-Iizuka allowed strong decay behaviors. In this scheme, we also predict the third radial excitation of the ${a}_{0}(980)$, which is denoted as the ${a}_{0}(2115)$, accessible at future experiment as a direct test of this assignment. We find another Regge trajectory which contains three isoscalar scalar states ${f}_{0}(980)$, $X(1812)$, and ${f}_{0}(2100)$. We investigate their two-body Okubo-Zweig-Iizuka allowed strong decay patterns, which are roughly consistent with the experimental data. The ${f}_{0}(980)$, $X(1812)$, and ${f}_{0}(2100)$ can be well grouped into the isoscalar scalar meson family. We want to emphasize that these two Regge trajectories have a similar slope. In summary, the present work provides a scheme of constructing the scalar meson family based on these reported scalar states. The possibility of the ${f}_{0}(1710)$ as the candidate of the scalar glueball cannot be excluded by the observation of the ${a}_{0}(1817)$ since the ${a}_{0}(1817)$ is more suitable as the isovector partner of the $X(1812)$.