  A wave equation with mass term is studied for all particles and antiparticles
of the first generation: electron and its neutrino, positron and antineutrino,
quarks $u$ and $d$ with three states of color and antiquarks $\overline{u}$ and
$\overline{d}$. This wave equation is form invariant under the $Cl_3^*$ group
generalizing the relativistic invariance. It is gauge invariant under the
$U(1)\times SU(2) \times SU(3)$ group of the standard model of quantum physics.
The wave is a function of space and time with value in the Clifford algebra
$Cl_{1,5}$. All features of the standard model, charge conjugation, color, left
waves, Lagrangian formalism, are linked to the geometry of this extended
space-time.
