A Stable Sexaquark: Overview and Discovery Strategies
  The neutral, flavor singlet scalar uuddss bound state -- the sexaquark, S --
may have a low enough mass to be stable or extremely long-lived. Here we review
mass estimates and production expectations and show that laboratory experiments
to date do not rule out such a long-lived state. An S with mass below 2054 MeV
is either absolutely stable or has a lifetime greater than the age of the
Universe. Detection of a stable S in accelerator experiments is very
challenging. An examination of the experimental literature shows that such an
effectively stable state would have escaped detection. The strongest laboratory
constraint on a long-lived S comes from the lower-bound on its formation time
in a doubly-strange hypernucleus; this constraint is, however, not stringent
enough to exclude a stable S. We develop strategies to discover it. A stable S
would be an attractive dark matter candidate. Relevant astrophysical and
cosmological observations, which show that sexaquark dark matter is consistent
with all current knowledge, are briefly reviewed.
