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Determination of the QCD coupling from ALEPH τ decay data

Rodríguez-Sánchez, Antonio LU and Pich, Antonio (2016) In Physical Review D 94(3).
Abstract

We present a comprehensive study of the determination of the strong coupling from τ decay, using the most recent release of the experimental ALEPH data. We critically review all theoretical strategies used in previous works and put forward various novel approaches which allow one to study complementary aspects of the problem. We investigate the advantages and disadvantages of the different methods, trying to uncover their potential hidden weaknesses and test the stability of the obtained results under slight variations of the assumed inputs. We perform several determinations, using different methodologies, and find a very consistent set of results. All determinations are in excellent agreement, and allow us to extract a very reliable... (More)

We present a comprehensive study of the determination of the strong coupling from τ decay, using the most recent release of the experimental ALEPH data. We critically review all theoretical strategies used in previous works and put forward various novel approaches which allow one to study complementary aspects of the problem. We investigate the advantages and disadvantages of the different methods, trying to uncover their potential hidden weaknesses and test the stability of the obtained results under slight variations of the assumed inputs. We perform several determinations, using different methodologies, and find a very consistent set of results. All determinations are in excellent agreement, and allow us to extract a very reliable value for αs(mτ2). The main uncertainty originates in the pure perturbative error from unknown higher orders. Taking into account the systematic differences between the results obtained with the contour-improved perturbation theory and fixed-order perturbation theory prescriptions, we find αs(nf=3)(mτ2)=0.328±0.013 which implies αs(nf=5)(MZ2)=0.1197±0.0015.

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author
publishing date
type
Contribution to journal
publication status
published
subject
in
Physical Review D
volume
94
issue
3
article number
034027
publisher
American Physical Society
external identifiers
  • scopus:84984868287
ISSN
2470-0010
DOI
10.1103/PhysRevD.94.034027
language
English
LU publication?
no
id
91683064-e734-4bd4-859f-623d6c88da13
date added to LUP
2019-05-14 13:59:30
date last changed
2019-12-10 08:04:13
@article{91683064-e734-4bd4-859f-623d6c88da13,
  abstract     = {<p>We present a comprehensive study of the determination of the strong coupling from τ decay, using the most recent release of the experimental ALEPH data. We critically review all theoretical strategies used in previous works and put forward various novel approaches which allow one to study complementary aspects of the problem. We investigate the advantages and disadvantages of the different methods, trying to uncover their potential hidden weaknesses and test the stability of the obtained results under slight variations of the assumed inputs. We perform several determinations, using different methodologies, and find a very consistent set of results. All determinations are in excellent agreement, and allow us to extract a very reliable value for αs(mτ2). The main uncertainty originates in the pure perturbative error from unknown higher orders. Taking into account the systematic differences between the results obtained with the contour-improved perturbation theory and fixed-order perturbation theory prescriptions, we find αs(nf=3)(mτ2)=0.328±0.013 which implies αs(nf=5)(MZ2)=0.1197±0.0015.</p>},
  author       = {Rodríguez-Sánchez, Antonio and Pich, Antonio},
  issn         = {2470-0010},
  language     = {eng},
  month        = {08},
  number       = {3},
  publisher    = {American Physical Society},
  series       = {Physical Review D},
  title        = {Determination of the QCD coupling from ALEPH τ decay data},
  url          = {http://dx.doi.org/10.1103/PhysRevD.94.034027},
  doi          = {10.1103/PhysRevD.94.034027},
  volume       = {94},
  year         = {2016},
}