Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: New Measurement of the Electron Magnetic Moment and the Fine Structure
  Constant   A measurement using a one-electron quantum cyclotron gives the electron
magnetic moment in Bohr magnetons, g/2 = 1.001 159 652 180 73 (28) [0.28 ppt],
with an uncertainty 2.7 and 15 times smaller than for previous measurements in
2006 and 1987. The electron is used as a magnetometer to allow lineshape
statistics to accumulate, and its spontaneous emission rate determines the
correction for its interaction with a cylindrical trap cavity. The new
measurement and QED theory determine the fine structure constant, with
alpha^{-1} = 137.035 999 084 (51) [0.37 ppb], and an uncertainty 20 times
smaller than for any independent determination of alpha.

31
The categories of this paper are: ao-sci
1
The categories of this paper are: cs
37
The categories of this paper are: supr-con
25
The categories of this paper are: patt-sol
16
The categories of this paper are: stat
9
The categories of this paper are: nlin
11
The categories of this paper are: hep-lat
29
The categories of this paper are: funct-an
13
The categories of this paper are: quant-ph
2
The categories of this paper are: math
18
The categories of this paper are: econ
36
The categories of this paper are: cmp-lg
6
The categories of this paper are: astro-ph
32
The categories of this paper are: atom-ph
12
The categories of this paper are: nucl-th
15
The categories of this paper are: nucl-ex