Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Absence of evidence of superconductivity in sulfur hydride in optical
  reflectance experiments   Capitani and coworkers [1] reported that infrared optical reflectance
measurements provided evidence for a superconducting transition in sulfur
hydride [2] under 150 GPa pressure, and that the transition is driven by the
electron-phonon interaction. Here we argue that the measured data did not
provide evidence that the system undergoes a transition to a superconducting
state, nor do the data support any role of phonons in driving a transition.
Rather, the data are consistent with the system remaining in the normal state
down to temperature 50K, the lowest temperature measured in the experiment.
This calls into further question [3,4] the generally accepted view [5] that
sulfur hydride under pressure is a high temperature superconductor.

7
The categories of this paper are: hep-th
18
The categories of this paper are: econ
10
The categories of this paper are: q-bio
6
The categories of this paper are: astro-ph
14
The categories of this paper are: math-ph
27
The categories of this paper are: comp-gas
32
The categories of this paper are: atom-ph
8
The categories of this paper are: hep-ex
0
The categories of this paper are: hep-ph
2
The categories of this paper are: math
5
The categories of this paper are: gr-qc
9
The categories of this paper are: nlin
3
The categories of this paper are: physics
12
The categories of this paper are: nucl-th
1
The categories of this paper are: cs
28
The categories of this paper are: alg-geom