Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Identification of significant $E0$ strength in the $2^+_2 \rightarrow
  2^+_1$ transitions of $^{58, 60, 62}$Ni   The $E0$ transition strength in the $2^+_2 \rightarrow 2^+_1$ transitions of
$^{58,60,62}$Ni have been determined for the first time following a series of
measurements at the Australian National University (ANU) and the University of
Kentucky (UK). The CAESAR Compton-suppressed HPGe array and the Super-e
solenoid at ANU were used to measure the $\delta(E2/M1)$ mixing ratio and
internal conversion coefficient of each transition following inelastic proton
scattering. Level half-lives, $\delta(E2/M1)$ mixing ratios and $\gamma$-ray
branching ratios were measured at UK following inelastic neutron scattering.
The new spectroscopic information was used to determine the $E0$ strengths.
These are the first $2^+ \rightarrow 2^+$ $E0$ transition strengths measured in
nuclei with spherical ground states and the $E0$ component is found to be
unexpectedly large; in fact, these are amongst the largest $E0$ transition
strengths in medium and heavy nuclei reported to date.

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The categories of this paper are: nlin
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The categories of this paper are: ao-sci
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The categories of this paper are: chem-ph
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The categories of this paper are: alg-geom
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The categories of this paper are: hep-ex
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The categories of this paper are: bayes-an
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The categories of this paper are: q-bio
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The categories of this paper are: gr-qc
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The categories of this paper are: atom-ph
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The categories of this paper are: econ
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The categories of this paper are: comp-gas
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The categories of this paper are: q-alg
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The categories of this paper are: hep-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: astro-ph