Determination of the QCD ? Parameter and the Accuracy of Perturbation Theory at High Energies
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Dalla Brida M, Fritzsch P, Korzec T, Ramos A, Sint S, Sommer R, Determination of the QCD ? Parameter and the Accuracy of Perturbation Theory at High Energies, Physical Review Letters, 117, 18, 2016, 182001-Download Item:
Abstract:
We discuss the determination of the strong coupling
α
MS
ð
m
Z
Þ
or, equivalently, the QCD
Λ
parameter. Its
determination requires the use of perturbation theory in
α
s
ð
μ
Þ
in some scheme
s
and at some energy scale
μ
.
The higher the scale
μ
, the more accurate perturbation theory becomes, owing to asymptotic freedom. As
one step in our computation of the
Λ
parameter in three-flavor QCD, we perform lattice computations in a
scheme that allows us to nonperturbatively reach very high energies, corresponding to
α
s
¼
0
.
1
and below.
We find that (continuum) perturbation theory is very accurate there, yielding a 3% error in the
Λ
parameter,
while data around
α
s
≈
0
.
2
are clearly insufficient to quote such a precision. It is important to realize that
these findings are expected to be generic, as our scheme has advantageous properties regarding the
applicability of perturbation theory.
Author's Homepage:
http://people.tcd.ie/sintshttp://people.tcd.ie/fritzscp
Description:
PUBLISHEDExport Date: 6 January 2017
Author: Sint, Stefan; Fritzsch, Patrick
Type of material:
Journal ArticleSeries/Report no:
Physical Review Letters117
18
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Full text availableKeywords:
accurate perturbation theoryDOI:
http://dx.doi.org/10.1103/PhysRevLett.117.182001Metadata
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