Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Non-perturbative Expansion, Renormalons, and $\tau$ Decay   We analyze inclusive $\tau$ decay using a modified version of the $a$
expansion, a non-perturbative technique in which the effective coupling is
analytic in the infrared region. The modification involves renormalization
group improvement of the integrand in a spectral representation for the
D-function prior to implementing the $a$ expansion. The advantage of this
approach is that it enables us to monitor the structure of the induced power
corrections and to ensure that these are consistent with the operator product
expansion. Numerically the method agrees well with experiment: the comparison
is made with the physical quantity $R_Z$ using $R_\tau$ as input.

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The categories of this paper are: econ
21
The categories of this paper are: adap-org
22
The categories of this paper are: chao-dyn
12
The categories of this paper are: nucl-th
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The categories of this paper are: solv-int
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The categories of this paper are: astro-ph
7
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: chem-ph
5
The categories of this paper are: gr-qc
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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: hep-lat
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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: comp-gas