Search for ∆S = 2 nonleptonic hyperon decays Ω− → Σ0π− and Ω− → nK−

A bstract Using (27 . 12 ± 0 . 14) × 10 8 ψ (3686) events collected by the BESIII detector at the center-of-mass energy of $$ \sqrt{s} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msqrt> <mml:mi>s</mml:mi> </mml:msqrt> </mml:math> = 3 . 686 GeV, we search for the first time for two nonleptonic hyperon decays that change strangeness by two units, Ω − → Σ 0 π − and Ω − → nK − . No significant signal is observed. The upper limits on their decay branching fractions are determined to be $$ \mathcal{B} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>B</mml:mi> </mml:math> (Ω − → Σ 0 π − ) &lt; 5 . 4 × 10 − 4 and $$ \mathcal{B} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>B</mml:mi> </mml:math> (Ω − → nK − ) &lt; 2 . 4 × 10 − 4 at the 90% confidence level.