Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Radiative recombination of twisted electrons with bare nuclei: going
  beyond the Born approximation   We present a fully relativistic investigation of the radiative recombination
of a twisted electron with a bare heavy nucleus. The twisted electron is
described by the wave function which accounts for the interaction with the
nucleus in all orders in $\alpha Z$. We use this wave function to derive the
probability of the radiative recombination with a single ion being shifted from
the twisted electron propagation direction. We also consider more realistic
experimental scenarios where the target is either localized (mesoscopic) or
infinitely wide (macroscopic). The situation when the incident electron is a
coherent superposition of two vortex states is considered as well. For the
nonrelativistic case we present analytical expressions which support our
numerical calculations. We study in details the influence of the electron
twistedness on the polarization and angular distribution of the emitted photon.
It is found that these properties of the outgoing photon might be very
sensitive to the total angular momentum and kinematic properties of twisted
beams. Therefore, the recombination of the twisted electrons can serve as a
valuable tool for atomic investigations as well as for the diagnostics of the
vortex electron beams.

12
The categories of this paper are: nucl-th
9
The categories of this paper are: nlin
5
The categories of this paper are: gr-qc
14
The categories of this paper are: math-ph
17
The categories of this paper are: q-fin
22
The categories of this paper are: chao-dyn
23
The categories of this paper are: solv-int
15
The categories of this paper are: nucl-ex
35
The categories of this paper are: mtrl-th
10
The categories of this paper are: q-bio
32
The categories of this paper are: atom-ph
2
The categories of this paper are: math
1
The categories of this paper are: cs
8
The categories of this paper are: hep-ex
30
The categories of this paper are: q-alg
7
The categories of this paper are: hep-th