Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Shirokov's contracting lifetimes and the interpretation of velocity
  eigenstates for unstable quantons   This paper is concerned with the interpretation of velocity eigenstates for
unstable quantons, their relationship to space like momentum eigenstates for
such quantons and the explanation of Shirokovs contracting lifetimes for such
velocity eigenstates. It is an elaboration of a portion of the authors earlier
study.

10
The categories of this paper are: q-bio
37
The categories of this paper are: supr-con
25
The categories of this paper are: patt-sol
15
The categories of this paper are: nucl-ex
33
The categories of this paper are: plasm-ph
35
The categories of this paper are: mtrl-th
0
The categories of this paper are: hep-ph
34
The categories of this paper are: chem-ph
8
The categories of this paper are: hep-ex
22
The categories of this paper are: chao-dyn
32
The categories of this paper are: atom-ph
28
The categories of this paper are: alg-geom
3
The categories of this paper are: physics
12
The categories of this paper are: nucl-th
30
The categories of this paper are: q-alg
9
The categories of this paper are: nlin