We present a simple analytic scheme for calculating the binding energy of excitons in semiconductors that takes full account of the existing anisotropy in the effective mass, as a complement to the qualitative treatment in most textbooks. Results obtained for excitons in gallium nitride form the basis for a discussion of the accuracy of this approach. Zusammenfassung. Wir präsentieren ein einfa...

Previously, people thought the effects of quantum corrections on neutrino mass matrix may be negligible, since the Yukawa couplings of neutrinos are much much smaller than other quarks and leptons. However, is it true?? Besides, are “maximal” mixings in the lepton flavor mixing matrix stable against quantum corrections? My talk is concentrating on these topics in the framework of the minimal su...

New physics in the lepton sector may account for neutrino masses, affect electroweak precision observables, induce charged-lepton flavor violation, and shift dipole moments. The low-energy predictions of different models are most conveniently compared within formalism effective field theory. To illustrate benefits this approach, we derive Wilson coefficients a set representative models: fermion...

In this work, we readdress the Dirac equation in position-dependent mass (PDM) scenario. Here, one investigates quantum dynamics of non-Hermitian fermionic particles with effective assuming a $(1+1)$-dimension flat spacetime. seeking Schr\"{o}dinger-like theory PT symmetry is appropriate to assume complex potential. This imaginary interaction produces an potential purely dependent on distributi...