Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Shorter 146Sm Half-Life Measured and Implications for 146Sm-142Nd
  Chronology in the Solar System   The extinct p-process nuclide 146Sm serves as an astrophysical and
geochemical chronometer through measurements of isotopic anomalies of its
alpha-decay daughter 142Nd. Based on analyses of 146Sm/147Sm alpha-activity and
atom ratios, we determined the half-life of 146Sm to be 68 \pm 7 (1sigma)
million years (Ma), which is shorter than the currently used value of 103 \pm 5
Ma. This half-life value implies a higher initial 146Sm abundance in the early
solar system, (146Sm/144Sm_0 = 0.0094\pm0.0005 (2sigma), than previously
estimated. Terrestrial, Lunar and Martian planetary silicate mantle
differentiation events dated with 146Sm-142Nd converge to a shorter time span
and in general to earlier times, due to the combined effect of the new 146Sm
half-life and (146Sm/144Sm)_0 values.

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The categories of this paper are: math
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The categories of this paper are: atom-ph
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The categories of this paper are: alg-geom
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The categories of this paper are: q-alg
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The categories of this paper are: supr-con
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The categories of this paper are: funct-an
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The categories of this paper are: gr-qc
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The categories of this paper are: econ
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The categories of this paper are: ao-sci
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The categories of this paper are: math-ph
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The categories of this paper are: nucl-ex
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The categories of this paper are: solv-int
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The categories of this paper are: q-bio
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The categories of this paper are: nlin
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The categories of this paper are: plasm-ph
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The categories of this paper are: nucl-th