  The free parameters of a flat accelerating model without dark energy are
constrained by using Supernovae type Ia and observational H(z) data. Instead of
the vacuum dominance, the present accelerating stage in this modified
Einstein-de Sitter cosmology is a consequence of the gravitationally-induced
particle production of cold dark matter. The model present a transition from a
decelerating to an accelerating regime at low redshifts, and is also able to
harmonize a cold dark matter picture with the latest measurements of the Hubble
constant H_0, the Supernovae observations (Constitution sample), and the H(z)
data.
