A new perspective on quantum field theory revealing possible existence of another kind of fermions forming dark matter

Quantum fields are considered as generators of infinite-dimensional Clifford algebra $Cl(\infty)$, which can be either orthogonal (in case fermions) or symplectic bosons). A generic quantum state expressed a superposition the basis elements coefficients being multiparticle complex-valued wave functions. The elements, that products $Cl(\infty)$ in Witt basis, act creation and annihilation operators. They create positive negative energy states include bare Dirac vacuum special cases. It is shown nonvanishing electric charge arises from an extra dimension doubling number operators, brings imaginary unit ${\bar i}$ into description. further extension to consider one quaternionic units having values or, equivalently, complexified 2-dimensional algebra, $Cl(2)\otimes C$.contains two distinct fundamental representations $SU(2)$, associated with weak isospin oublet $(\nu_e,e^-)$, other doublet new leptons, denoted $(\epsilon^+,\nu_\epsilon)$, together quarks $(u',d')$ identified dark matter.