Observation of the Decay B_{s}^{0}→K^{0}K[over ¯]^{0}

Area of Science:

• Particle Physics
• High-Energy Physics
• Quantum Chromodynamics

Background:

• The B_{s}^{0} meson is a key probe for New Physics beyond the Standard Model.
• Understanding its decay modes, like B_{s}^{0}→K^{0}K[over ¯]^{0}, is crucial for testing theoretical predictions.

Purpose of the Study:

• To measure the branching fraction of the B_{s}^{0}→K^{0}K[over ¯]^{0} decay.
• To provide the first experimental observation of this specific decay channel.

Main Methods:

• Analysis of data collected by the Belle detector at the KEKB e^{+}e^{-} collider.
• Utilizing data from the ϒ(5S) resonance with an integrated luminosity of 121.4 fb^{-1}.

Main Results:

• The branching fraction for B_{s}^{0}→K^{0}K[over ¯]^{0} was measured as [19.6_{-5.1}^{+5.8}(stat)±1.0(syst)±2.0(N_{B_{s}^{0}B[over ¯]_{s}^{0}})]×10^{-6}.
• The observation achieved a statistical significance of 5.1 standard deviations.

Conclusions:

• This study presents the first observation of the B_{s}^{0}→K^{0}K[over ¯]^{0} decay.
• The measured branching fraction provides a new data point for theoretical models in particle physics.