  The origin of Jupiter-mass planets with orbital periods of only a few days is
still uncertain. It is widely believed that these planets formed near the
water-ice line of the protoplanetary disk, and subsequently migrated into much
smaller orbits. Most of the proposed migration mechanisms can be classified
either as disk-driven migration, or as excitation of a very high eccentricity
followed by tidal circularization. In the latter scenario, the giant planet
that is destined to become a hot Jupiter spends billions of years on a
highly-eccentric orbit, with apastron near the water-ice line. Eventually,
tidal dissipation at periastron shrinks and circularizes the orbit. If this is
correct, then it should be especially rare for hot Jupiters to be accompanied
by another giant planet interior to the water-ice line. Using the current
sample of giant planets discovered with the Doppler technique, we find that hot
Jupiters with P_orb < 10 days are no more or less likely to have exterior
Jupiter-mass companions than longer-period giant planets with P_orb >= 10 days.
This result holds for exterior companions both inside and outside of the
approximate location of the water-ice line. These results are difficult to
reconcile with the high-eccentricity migration scenario for hot Jupiter
formation.
