Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: 138La-138Ce-136Ce nuclear cosmochronometer of supernova neutrino process   The 138La (T1/2=102 Gyr) - 138Ce - 136Ce system is proposed to be used as a
nuclear cosmochronometer for measuring the time elapsed from a supernova
neutrino process. This chronometer is applied to examine a sample affected by a
single nucleosynthesis episode as presolar grains in primitive meteorites. A
feature of this chronometer is to evaluate the initial abundance ratio of
136Ce/138Ce using an empirical scaling law, which was found in the solar
abundances. We calculate the age of the sample as a function of isotopic
ratios, 136Ce/138Ce, and 138La/138Ce, and evaluate the age uncertainty due to
theoretical and observational errors. It is concluded that this chronometer can
work well for a sample with the abundance ratio of 138La/138Ce >= 20 when the
ratios of 136Ce/138Ce and 138La/138Ce are measured within the uncertainty of
20%. The availability of such samples becomes clear in recent studies of the
presolar grains. We also discuss the effect of the nuclear structure to the
neutrino process origin of 138La.

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The categories of this paper are: dg-ga
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The categories of this paper are: hep-lat
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The categories of this paper are: bayes-an
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The categories of this paper are: math
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The categories of this paper are: stat
0
The categories of this paper are: hep-ph
34
The categories of this paper are: chem-ph
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The categories of this paper are: mtrl-th
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The categories of this paper are: chao-dyn
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The categories of this paper are: cond-mat
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The categories of this paper are: hep-th
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The categories of this paper are: supr-con
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The categories of this paper are: hep-ex
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The categories of this paper are: plasm-ph
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The categories of this paper are: ao-sci
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The categories of this paper are: funct-an