Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On the accuracy of the optical determination of the proton charge radius   Determination of the proton charge radius by different methods has produced
an inconsistency. The most precise value (from spectroscopy of muonic hydrogen)
strongly disagrees with three less accurate values (from spectroscopy of
ordinary hydrogen and deuterium, from relative measurements of the cross
section of the elastic electron-proton scattering at MAMI and from evaluation
of the world data on absolute measurements of e-p cross sections). Here, we
question the accuracy of the determination of the proton charge radius by means
of spectroscopy of ordinary hydrogen and deuterium and demonstrate that its
accuracy was probably overestimated. In particular, we revisit determination
from each relevant transition and find that the results of two optical
experiments, which are the most statistically important, are not perfectly
consistent. The inconsistency is rather a `tension' between the results than
their discrepancy, however, it implies that a more conservative estimation of
the uncertainty is needed. With the more realistic estimation of the
uncertainty, the results for the proton charge radius from spectroscopy of
ordinary and muonic atoms are rather in fair agreement.

37
The categories of this paper are: supr-con
10
The categories of this paper are: q-bio
30
The categories of this paper are: q-alg
20
The categories of this paper are: acc-phys
24
The categories of this paper are: dg-ga
28
The categories of this paper are: alg-geom
7
The categories of this paper are: hep-th
36
The categories of this paper are: cmp-lg
6
The categories of this paper are: astro-ph
15
The categories of this paper are: nucl-ex
12
The categories of this paper are: nucl-th
9
The categories of this paper are: nlin
2
The categories of this paper are: math
32
The categories of this paper are: atom-ph
11
The categories of this paper are: hep-lat
14
The categories of this paper are: math-ph