Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The ZEKE-effect in cold Rydberg gases   Cold, dense Rydberg gases produced in a cold-atom trap are investigated using
spectroscopic methods and time-resolved electron counting. On the discrete
Rydberg resonances we observe large trap losses and long lasting electron
emission from the Rydberg gas (>30ms). Our observations are explained by
quasi-elastic l-mixing collisions between Rydberg atoms and slow electrons that
lead to the population of long-lived high-angular-momentum Rydberg states.
These atoms thermally ionize slowly and with large probabilities, leading to
the observed effects.

25
The categories of this paper are: patt-sol
12
The categories of this paper are: nucl-th
11
The categories of this paper are: hep-lat
7
The categories of this paper are: hep-th
35
The categories of this paper are: mtrl-th
26
The categories of this paper are: bayes-an
30
The categories of this paper are: q-alg
34
The categories of this paper are: chem-ph
27
The categories of this paper are: comp-gas
18
The categories of this paper are: econ
1
The categories of this paper are: cs
37
The categories of this paper are: supr-con
28
The categories of this paper are: alg-geom
22
The categories of this paper are: chao-dyn
2
The categories of this paper are: math
24
The categories of this paper are: dg-ga