Using pure spinors, the superstring was recently quantized in a manifestly tendimensional super-Poincaré covariant manner and a covariant prescription was given for tree-level scattering amplitudes. In this paper, we prove that this prescription is cyclically symmetric and, for the scattering of an arbitrary number of massless bosons and up to four massless fermions, it agrees with the standard...

We give an action for the massless spinning particle in pseudoclassical mechanics by using grassmann variables. The constructed action is invariant under τ -reparametrizations, local SUSY and O(N) transformations. After quantization, for the special case N = 2, we get an action which describes the spin 0, 1 and topological sectors of the massless DKP theory.

A dark photon is predicted by several well-motivated Standard Model extensions and UV completions. Here the most general effective field theory up to dimension-six operators describing interactions of a massless with all particles considered. This captures predictions generic model featuring this type vector boson at sufficiently low energies. In such framework thermal production rate photons c...

Zitterbewegung of massless particles with an arbitrary spin is analyzed in various representations. Dynamics the group velocity a particle as whole and corresponding radius vector determined. This defines any fixed point envelope moving wave packet characterizing its differs from velocities points wavefront. We consider free scalar Dirac particles, photon, massive describe them different For sp...

We calculate one loop corrections to the domain-wall quark propagator in QCD. We show how the wave function is renormalized in this theory. Especially we are interested in the behavior of the massless fermion mode, which exists near the domain wall at the tree level. We show that this massless mode is stable against the quantum correction.