Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: New limit for the half-life of double beta decay of $^{94}$Zr to the
  first excited state of $^{94}$Mo   Neutrinoless Double Beta Decay is a phenomenon of fundamental interest in
particle physics. The decay rates of double beta decay transitions to the
excited states can provide input for Nuclear Transition Matrix Element
calculations for the relevant two neutrino double beta decay process. It can be
useful as supplementary information for the calculation of Nuclear Transition
Matrix Element for the neutrinoless double beta decay process. In the present
work, double beta decay of $^{94}$Zr to the $2^{+}_{1}$ excited state of
$^{94}$Mo at 871.1 keV is studied using a low background $\sim$ 230 cm$^3$ HPGe
detector. No evidence of this decay was found with a 232 g.y exposure of
natural Zirconium. The lower half-life limit obtained for the double beta decay
of $\rm^{94}Zr$ to the $2^{+}_{1}$ excited state of $\rm^{94}Mo$ is $T_{1/2}
(0\nu + 2\nu)> 3.4 \times 10^{19}$ y at 90% C.L., an improvement by a factor of
$\sim$ 4 over the existing experimental limit at 90\% C.L. The sensitivity is
estimated to be $T_{1/2} (0\nu + 2\nu) > 2.0\times10^{19}$ y at 90% C.L. using
the Feldman-Cousins method.

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The categories of this paper are: eess
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The categories of this paper are: q-alg
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The categories of this paper are: alg-geom
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The categories of this paper are: astro-ph
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The categories of this paper are: mtrl-th
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The categories of this paper are: plasm-ph
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The categories of this paper are: patt-sol
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The categories of this paper are: ao-sci
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The categories of this paper are: nucl-th
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The categories of this paper are: physics
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The categories of this paper are: math-ph
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The categories of this paper are: hep-ex
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The categories of this paper are: funct-an
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The categories of this paper are: q-fin
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The categories of this paper are: chem-ph
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The categories of this paper are: gr-qc