Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quantum test of the Universality of Free Fall using rubidium and
  potassium   We report on an improved test of the Universality of Free Fall using a
rubidium-potassium dual-species matter wave interferometer. We describe our
apparatus and detail challenges and solutions relevant when operating a
potassium interferometer, as well as systematic effects affecting our
measurement. Our determination of the E\"otv\"os ratio yields
$\eta_{\,\text{Rb,K}}=-1.9\times10^{-7}$ with a combined standard uncertainty
of $\sigma_\eta=3.2\times10^{-7}$.

10
The categories of this paper are: q-bio
21
The categories of this paper are: adap-org
28
The categories of this paper are: alg-geom
22
The categories of this paper are: chao-dyn
8
The categories of this paper are: hep-ex
17
The categories of this paper are: q-fin
23
The categories of this paper are: solv-int
0
The categories of this paper are: hep-ph
9
The categories of this paper are: nlin
11
The categories of this paper are: hep-lat
25
The categories of this paper are: patt-sol
32
The categories of this paper are: atom-ph
26
The categories of this paper are: bayes-an
18
The categories of this paper are: econ
2
The categories of this paper are: math
37
The categories of this paper are: supr-con