Search for a Stable Six-Quark State at BABAR.

Area of Science:

• Particle Physics
• Cosmology
• Nuclear Physics

Background:

• Recent theories propose a stable, deeply bound six-quark state (S) with composition uuddss.
• This exotic particle is considered a potential dark matter candidate due to its unique properties.

Purpose of the Study:

• To conduct the first experimental search for a stable, doubly strange six-quark state (S).
• To investigate the potential existence of S by analyzing specific particle decays.

Main Methods:

• Analysis of ϒ(2S) and ϒ(3S) decays collected by the BABAR experiment.
• Searched for the decay signature ϒ→SΛ[over ¯]Λ[over ¯] to detect the hypothetical S particle.

Main Results:

• No statistically significant signal for the deeply bound six-quark state (S) was observed.
• 90% confidence level limits on the branching fraction for ϒ(2S,3S)→SΛ[over ¯]Λ[over ¯] were established between 1.2×10⁻⁷ and 1.4×10⁻⁷ for S masses below 2.05 GeV.

Conclusions:

• The study places stringent limits on the existence of the predicted deeply bound, doubly strange six-quark state (S).
• These findings constrain theoretical models proposing such exotic particles as dark matter candidates.