Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Relativistic quantum dynamics of neutral particle in external electric
  fields: An approach on effects of spin   The planar quantum dynamics of spin-1/2 neutral particle interacting with
electrical fields is considered. A set of first order differential equations
are obtained directly from the planar Dirac equation with nonminimum coupling.
New solutions of this system, in particular, for the Aharonov-Casher effect,
are found and discussed in detail. Pauli equation is also obtained by studying
the motion of the particle when it describes a circular path of constant
radius. We also analyze the planar dynamics in the full space, including the
$r=0$ region. The self-adjoint extension method is used to obtain the energy
levels and wave functions of the particle for two particular values for the
self-adjoint extension parameter. The energy levels obtained are analogous to
the Landau levels and explicitly depend on the spin projection parameter.

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The categories of this paper are: plasm-ph
24
The categories of this paper are: dg-ga
27
The categories of this paper are: comp-gas
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The categories of this paper are: supr-con
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The categories of this paper are: mtrl-th
4
The categories of this paper are: cond-mat
17
The categories of this paper are: q-fin
15
The categories of this paper are: nucl-ex
8
The categories of this paper are: hep-ex
23
The categories of this paper are: solv-int
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The categories of this paper are: acc-phys
22
The categories of this paper are: chao-dyn
30
The categories of this paper are: q-alg
5
The categories of this paper are: gr-qc
10
The categories of this paper are: q-bio
31
The categories of this paper are: ao-sci