Physicists narrow search for rare particle decay, closing theoretical loopholes
An international research team using China's BEPCII collider found no evidence for a predicted particle transformation, but the null result is scientifically valuable: it sets new limits on where exotic matter might hide. The finding refines models of fundamental physics that underpin next-generation detector design and particle research funding priorities.
Originaltitel: Search for <em>h<sub>c</sub></em> → π<sup>+</sup>π<sup>-</sup> <em>J</em>/ψ via ψ(3686) → <em>π<sup>0</sup>h<sub>c</sub></em>
<p>Using (2712.4 ± 14.3) x 10<sup>6</sup> ψ(3686) events collected with the BESIII detector operating at the BEPCII collider, we search for the hadronic transition h<sub>c</sub> → π<sup>+</sup>π<sup>-</sup>J/ψ via ψ(3686) → π<sup>0</sup>h<sub>c</sub>. No significant signal is observed. We set the most stringent upper limits to date on the branching fractions <em>B</em>(ψ(3686) → π<sup>0</sup>h<sub>c</sub>) x <em>B</em>(h<sub>c</sub> → π<sup>+</sup>π<sup>-</sup>J/ψ) and <em>B</em>(h<sub>c</sub> → π<sup>+</sup>π<sup>-</sup>J/ψ) at the 90% confidence level, which are determined to be 6.7 x 10<sup>-7</sup> and 9.4 x 10<sup>-4</sup>, respectively.</p>