Observation of the decay <math display='inline'> <mi>ψ</mi> <mo stretchy='false'>(</mo> <mn>3686</mn> <mo stretchy='false'>)</mo> <mo stretchy='false'>→</mo> <msup> <mi mathvariant='normal'>Σ<

<p> Using a dataset of <math display='inline'> <mo stretchy='false'>(</mo> <mn>27.12</mn> <mo>±</mo> <mn>0.14</mn> <mo stretchy='false'>)</mo> <mo>×</mo> <msup> <mn>10</mn> <mn>8</mn> </msup> <mtext> </mtext> <mtext> </mtext> <mi>ψ</mi> <mo stretchy='false'>(</mo> <mn>3686</mn> <mo stretchy='false'>)</mo> </math> events collected by the BESIII detector operating at the BEPCII collider, we report the first observation of the decay <math display='inline'> <mi>ψ</mi> <mo stretchy='false'>(</mo> <mn>3686</mn> <mo stretchy='false'>)</mo> <mo stretchy='false'>→</mo> <msup> <mi mathvariant='normal'>Σ</mi> <mn>0</mn> </msup> <msup> <mover accent='true'> <mi mathvariant='normal'>Σ</mi> <mo stretchy='false'>¯</mo> </mover> <mn>0</mn> </msup> <mi>ω</mi> </math> with a statistical significance of <math display='inline'> <mrow> <mn>8.9</mn> <mi>σ</mi> </mrow> </math> . The measured branching fraction is <math display='inline'> <mo stretchy='false'>(</mo> <mn>1.24</mn> <mo>±</mo> <mn>0.1</mn> <msub> <mn>6</mn> <mrow> <mi>stat</mi> </mrow> </msub> <mo>±</mo> <mn>0.1</mn> <msub> <mn>1</mn> <mi>sys</mi> </msub> <mo stretchy='false'>)</mo> <mo>×</mo> <msup> <mn>10</mn> <mrow> <mo>−</mo> <mn>5</mn> </mrow> </msup> </math> , where the first uncertainty is statistical and the second is systematic. Additionally, we investigate potential intermediate states in the invariant mass distributions of <math display='inline'> <msup> <mi mathvariant='normal'>Σ</mi> <mn>0</mn> </msup> <mi>ω</mi> </math> , <math display='inline'> <msup> <mover accent='true'> <mi mathvariant='normal'>Σ</mi> <mo stretchy='false'>¯</mo> </mover> <mn>0</mn> </msup> <mi>ω</mi> </math> and <math display='inline'> <msup> <mi mathvariant='normal'>Σ</mi> <mn>0</mn> </msup> <msup> <mover accent='true'> <mi mathvariant='normal'>Σ</mi> <mo stretchy='false'>¯</mo> </mover> <mn>0</mn> </msup> </math> . A hint of a resonanc. Authors: Ablikim, M.; Achasov, M. N.; Adlarson, P.; Ai, X. C.; Aliberti, R.. DOE Contract: FG02-05ER41374