Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Measuring the branching ratios from the $y^8 {\rm P}_{9/2}$ state to
  metastable states in europium   We measure the branching ratios from the $y^8{\rm P}_{9/2}$ excited state to
six metastable states of europium through fluorescence spectroscopy of an
atomic beam. The sum of the six branching ratios is estimated to be
$1.05(2)\times 10^{-3}$. This research provides us with insightful information
to determine the feasibility of using the $a^8{\rm S}_{7/2} - y^8{\rm P}_{9/2}$
transition in order to implement the Zeeman slowing for europium atoms in the
ground state. Based on this result, we also propose a scheme for Zeeman slowing
and magneto-optical trapping, using a specific metastable state which has a
cyclic transition.

37
The categories of this paper are: supr-con
31
The categories of this paper are: ao-sci
8
The categories of this paper are: hep-ex
23
The categories of this paper are: solv-int
36
The categories of this paper are: cmp-lg
22
The categories of this paper are: chao-dyn
14
The categories of this paper are: math-ph
28
The categories of this paper are: alg-geom
3
The categories of this paper are: physics
24
The categories of this paper are: dg-ga
5
The categories of this paper are: gr-qc
33
The categories of this paper are: plasm-ph
12
The categories of this paper are: nucl-th
16
The categories of this paper are: stat
18
The categories of this paper are: econ
35
The categories of this paper are: mtrl-th