Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Search of Neutrinoless Double Beta Decay with the GERDA Experiment   The Gerda experiment designed to search for the neutrinoless double beta
decay in 76Ge has successfully completed the first data collection. No signal
excess is found, and a lower limit on the half life of the process is set, with
T1/2 > 2.1x10^25 yr (90% CL). After a review of the experimental setup and of
the main Phase I results, the hardware upgrade for Gerda Phase II is described,
and the physics reach of the new data collection is reported.

16
The categories of this paper are: stat
1
The categories of this paper are: cs
2
The categories of this paper are: math
34
The categories of this paper are: chem-ph
11
The categories of this paper are: hep-lat
33
The categories of this paper are: plasm-ph
35
The categories of this paper are: mtrl-th
4
The categories of this paper are: cond-mat
17
The categories of this paper are: q-fin
25
The categories of this paper are: patt-sol
8
The categories of this paper are: hep-ex
23
The categories of this paper are: solv-int
30
The categories of this paper are: q-alg
32
The categories of this paper are: atom-ph
13
The categories of this paper are: quant-ph
24
The categories of this paper are: dg-ga