Big Bang Nucleosynthesis with long-lived strongly interacting relic
  particles
  We study effects of relic long-lived strongly interacting massive particles
(X particles) on big bang nucleosynthesis (BBN). The X particle is assumed to
have existed during the BBN epoch, but decayed long before detected. The
interaction strength between an X and a nucleon is assumed to be similar to
that between nucleons. Rates of nuclear reactions and beta decay of X-nuclei
are calculated, and the BBN in the presence of neutral charged X^0 particles is
calculated taking account of captures of X^0 by nuclei. As a result, the X^0
particles form bound states with normal nuclei during a relatively early epoch
of BBN leading to the production of heavy elements. Constraints on the
abundance of X^0 are derived from observations of primordial light element
abundances. Particle models which predict long-lived colored particles with
lifetimes longer than about 200 s are rejected. This scenario prefers the
production of 9Be and 10B. There might, therefore, remain a signature of the X
particle on primordial abundances of those elements. Possible signatures left
on light element abundances expected in four different models are summarized.
