Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: 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.

11
The categories of this paper are: hep-lat
14
The categories of this paper are: math-ph
9
The categories of this paper are: nlin
35
The categories of this paper are: mtrl-th
6
The categories of this paper are: astro-ph
22
The categories of this paper are: chao-dyn
29
The categories of this paper are: funct-an
1
The categories of this paper are: cs
4
The categories of this paper are: cond-mat
28
The categories of this paper are: alg-geom
36
The categories of this paper are: cmp-lg
5
The categories of this paper are: gr-qc
37
The categories of this paper are: supr-con
27
The categories of this paper are: comp-gas
7
The categories of this paper are: hep-th
0
The categories of this paper are: hep-ph