Wave Packet Dynamics in the Majorana Equation

In the Majorana equation for particles with arbitrary spin, wave packets occur due to not only the uncertainty that affects position and momentum but also due to infinite components with decreasing mass that form the Majorana spinor. In this paper, we prove that such components contribute to increase the spreading of wave packets. Moreover, Zitterbewegung takes place in both the time propagation of Dirac wave packets and in Majorana wave packets. However, it shows a peculiar fine structure. Finally, group velocity always remains subluminal and contributions due to infinite components decrease progressively as spin increases.