Search for a Stable Six-Quark State at BABAR

TL;DR

This paper reports a search for a hypothesized stable six-quark state using BABAR data, setting upper limits on its production and thus constraining its possible existence as a dark matter candidate.

Contribution

First experimental search for a stable six-quark state in Upsilon decays, providing the most stringent limits to date on its production rate.

Findings

No signal observed for the six-quark state.

Upper limits on branching fractions are set at (1.2-1.4)×10^-7.

Results strongly constrain the existence of such exotic particles.

Abstract

Recent investigations have suggested that the six-quark combination uuddss could be a deeply bound state (S) that has eluded detection so far, and a potential dark matter candidate. We report the first search for a stable, doubly strange six-quark state in Upsilon -> S anti-Lambda anti-Lambda decays based on a sample of 90 million Upsilon(2S) and 110 million Upsilon(3S) decays collected by the BABAR experiment. No signal is observed, and 90% confidence level limits on the combined Upsilon(2S,3S) -> S anti-Lambda anti-Lambda branching fraction in the range (1.2-1.4)x10^-7 are derived for m_S < 2.05 GeV. These bounds set stringent limits on the existence of such exotic particles.