Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Fermions with a bounded and discrete mass spectrum   A mechanism for determining fermion masses in four spacetime dimensions is
presented, which uses a scalar-field domain wall extending in a fifth spacelike
dimension and a special choice of Yukawa coupling constants. A bounded and
discrete fermion mass spectrum is obtained analytically for spinors localized
in the fifth dimension. These particular mass values depend on a combination of
the absolute value of the Yukawa coupling constant and the parameters of the
scalar potential. A similar mechanism for a finite mass spectrum may apply to
$(1+1)$--dimensional fermions relevant to condensed matter physics.

20
The categories of this paper are: acc-phys
15
The categories of this paper are: nucl-ex
4
The categories of this paper are: cond-mat
37
The categories of this paper are: supr-con
18
The categories of this paper are: econ
17
The categories of this paper are: q-fin
2
The categories of this paper are: math
27
The categories of this paper are: comp-gas
0
The categories of this paper are: hep-ph
16
The categories of this paper are: stat
23
The categories of this paper are: solv-int
14
The categories of this paper are: math-ph
8
The categories of this paper are: hep-ex
6
The categories of this paper are: astro-ph
12
The categories of this paper are: nucl-th
24
The categories of this paper are: dg-ga