Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Measurement of the charged pion mass using a low-density target of light
  atoms   We present a new evaluation of the negatively charged pion mass based on the
simultaneous spec-troscopy of pionic nitrogen and muonic oxygen transitions
using a gaseous target composed by a N 2 /O 2 mixture at 1.4 bar. We present
the experimental setup and the methods for deriving the pion mass value from
the spatial separation from the 5g -- 4 f $\pi$N transition line and the 5g --
4 f $\mu$O transition line used as reference. Moreover, we discuss the
importance to use dilute targets in order to minimize the influence of
additional spectral lines from the presence of remaining electrons during the
radiative emission. The occurrence of possible satellite lines is investigated
via hypothesis testing methods using the Bayes factor.

26
The categories of this paper are: bayes-an
21
The categories of this paper are: adap-org
16
The categories of this paper are: stat
22
The categories of this paper are: chao-dyn
28
The categories of this paper are: alg-geom
17
The categories of this paper are: q-fin
27
The categories of this paper are: comp-gas
14
The categories of this paper are: math-ph
35
The categories of this paper are: mtrl-th
10
The categories of this paper are: q-bio
4
The categories of this paper are: cond-mat
29
The categories of this paper are: funct-an
32
The categories of this paper are: atom-ph
6
The categories of this paper are: astro-ph
23
The categories of this paper are: solv-int
34
The categories of this paper are: chem-ph