  New symmetry properties are found for pointlike scalar and Dirac particles
(Higgs boson and all leptons) in Riemannian and Riemann-Cartan spacetimes in
the presence of electromagnetic interactions. A Hermitian form of the
Klein-Gordon equation for a pointlike scalar particle in an arbitrary
n-dimensional Riemannian (or Riemann-Cartan) spacetime is obtained. New
conformal symmetries of initial and Hermitian forms of this equation are
ascertained. In the above spacetime, general Hamiltonians in the generalized
Feshbach-Villars and Foldy-Wouthuysen representations are derived. The
conformal-like transformation conserving these Hamiltonians is found.
Corresponding conformal symmetries of a Dirac particle are determined. It is
proven that all conformal symmetries remain unchanged by an inclusion of
electromagnetic interactions.
