  First principle study of QCD at finite temperature $T$ and chemical potential
$\mu$ is essential for understanding a wide range of phenomena from heavy-ion
collisions to cosmology and neutron stars. However, in the presence of finite
density, the critical behavior lattice gauge theory without species doubling,
is unknown. At strong coupling, we examine the phase structure on the $(\mu,T)$
plane, using Hamiltonian lattice QCD with Wilson fermions. A tricritical point
is found, separating the first and second order chiral phase transitions. Such
a tricritical point at finite $T$ has not been found in previous work in the
Hamiltonian formalism with Kogut-Susskind fermions or naive fermions.
