Asteroseismology of red-clump stars with CoRoT and Kepler
  The availability of asteroseismic constraints for a large number of red
giants with CoRoT and in the near future with Kepler, paves the way for
detailed studies of populations of galactic-disk red giants. We investigate
which information on the observed population can be recovered by the
distribution of the observed seismic constraints: the frequency of maximum
power of solar-like oscillations ($\nu_{max}$) and the large frequency
separation ($\Delta\nu$). We use the distribution of $\nu_{max}$ and of
$\Delta\nu$ observed by CoRoT in nearly 800 red giants in the first long
observational run, as a tool to investigate the properties of galactic
red-giant stars through the comparison with simulated distributions based on
synthetic stellar populations.
  We can clearly identify the bulk of the red giants observed by CoRoT as
red-clump stars, i.e. post-flash core-He-burning stars. The distribution of
$\nu_{max}$ and of $\Delta\nu$ give us access to the distribution of the
stellar radius and mass, and thus represent a most promising probe of the age
and star formation rate of the disk, and of the mass-loss rate during the
red-giant branch.
  This approach will be of great utility also in the interpretation of
forthcoming surveys of variability of red giants with CoRoT and Kepler. In
particular, an asteroseismic mass estimate of clump stars in the old-open
clusters observed by Kepler, would represent a most valuable observational test
of the poorly known mass-loss rate on the giant branch, and of its dependence
on metallicity.
