  We investigate the validity of the hyperhoop conjecture, which claims to
determine a necessary and sufficient condition for the formation of black hole
horizons in higher-dimensional space-times. Here we consider momentarily
static, conformally flat initial data sets each describing a gravitational
field of uniform massive k-sphere sources, for k=1,2, on the five-dimensional
Cauchy surface. The numerical result shows the validity of the hyperhoop
conjecture for a wide range of model parameters. We also confirm for the first
time the existence of an apparent horizon homeomorphism to S**2 x S**2 or S**1
x S**3, which is a higher-dimensional generalization of the black ring.
