Sakata model of hadrons revisited

46 years ago the quark model replaced the Sakata model as the standard explanation of the hadron structure. The major alleged defect of the Sakata model was its prediction of just too many types of particles, which have not been seen in experiments. However, this allegation was made without detailed consideration of the forces acting between sakatons. In this article we suggest a set of pairwise sakaton-sakaton and sakaton-antisakaton potentials that describe stability and masses of strongly interacting elementary particles in a good agreement with observations.Comment: 11 pages, 1 figure, 7 table

Moving unstable particles and special relativity

In Poincare-Wigner-Dirac theory of relativistic interactions, boosts are dynamical. This means that - just like time translations - boost transformations have non-trivial effect on internal variables of interacting systems. This is different from space translations and rotations, whose actions are always universal, trivial and interaction-independent. Applying this theory to unstable particles viewed from a moving reference frame, we prove that the decay probability cannot be invariant with respect to boosts. Different moving observers may see different internal compositions of the same unstable particle. Unfortunately, this effect is too small to be noticeable in modern experiments.Comment: 7 pages, 2 figures; submitted to Advances in High Energy Physic

A study of local and non-local spatial densities in quantum field theory

We use a one-dimensional model system to compare the predictions of two different 'yardsticks' to compute the position of a particle from its quantum field theoretical state. Based on the first yardstick (defined by the Newton-Wigner position operator), the spatial density can be arbitrarily narrow and its time-evolution is superluminal for short time intervals. Furthermore, two spatially distant particles might be able to interact with each other outside the light cone, which is manifested by an asymmetric spreading of the spatial density. The second yardstick (defined by the quantum field operator) does not permit localized states and the time evolution is subluminal.Comment: 29 pages, 3 figure