  We investigate ultrarelativistic collisions of the 12C nucleus with heavy
targets and show that the harmonic flow measures based on ratios of cumulant
moments are particularly suited to study the intrinsic deformation of the 12C
wave function. That way one can probe the expected alpha clusterization in the
ground state, which leads to large initial triangularity in the shape of the
fireball in the transverse plane. We show that the clusterization effect
results in very characteristic behavior of the ratios of the cumulant moments
as functions of the number of participant nucleons, both for the elliptic and
triangular deformations. Thus the experimental event-by-event studies of
harmonic flow in ultrarelativistic light-heavy collisions may offer a new
window to look at the ground-state structure of light nuclei.
