Hadronic corrections at 
                ${\cal O}(\alpha^2)$
               to the energy spectrum of muon decay

Davydychev, Andrei I.; Schilcher, Karl; Spiesberger, H.

doi:10.1007/s100520100577

Cited by 22 publications

(19 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The possible contribution to the uncertainty from strong interactions is negligible in our case, since it is suppressed at least by (α/π) 2 , and the lowest order the contribution of hadronic virtual pairs was found in Ref. [36] to be small itself. An estimate of the omitted contributions by a simple counting of powers of the finestructure constant and the large logarithm is not very safe, because there could be some extra enhancement factors, like numerically large constant coefficients or powers of ln(1−x) (the latter is partially taken into account by exponentiation).…”

Section: Discussionsupporting

confidence: 53%

Higher order QED corrections to muon decay spectrum

Arbuzov¹

2003

J. High Energy Phys.

View full text Add to dashboard Cite

show abstract

Section: Discussionsupporting

confidence: 53%

Higher order QED corrections to muon decay spectrum

Arbuzov¹

2003

J. High Energy Phys.

View full text Add to dashboard Cite

show abstract

“…represents the electromagnetic radiative corrections, which have been calculated to Oð 2 Þ. Corrections due to the strong interaction in loops give a fractional contribution on the order of 4 Â 10 À7 [6], which is more than 2 orders of magnitude smaller than the ultimate precision goals of TWIST. The quantities , , , and , often called the Michel parameters, are bilinear combinations of the weak coupling constants and describe the shape of the decay spectrum.…”

Section: Introductionmentioning

confidence: 99%

Precision measurement of the muon decay parametersρandδ

MacDonald¹,

Bayes²,

Bueno³

et al. 2008

Phys. Rev. D

View full text Add to dashboard Cite

The TWIST Collaboration has performed new measurements of two of the parameters that describe muon decay: , which governs the shape of the overall momentum spectrum, and , which governs the momentum dependence of the parity-violating decay asymmetry. This analysis gives the results ¼ 0:750 14 AE 0:000 17ðstatÞ AE 0:000 44ðsystÞ AE 0:000 11ðÞ, where the last uncertainty arises from the correlation between and the decay parameter , and ¼ 0:750 67 AE 0:000 30ðstatÞ AE 0:000 67ðsystÞ. These are consistent with the value of 3=4 given for both parameters in the standard model of particle physics, and are a factor of two more precise than the measurements previously published by TWIST. A new global analysis of all available muon decay data incorporating these results is presented. Improved lower and upper limits on the decay parameter P of 0:995 24 < P < 1:000 91 at 90% confidence are determined, where P is the polarization of the muon when it is created during pion decay, and governs the muon decay asymmetry. These results set new model-independent constraints on the possible weak interactions of right-handed particles. Specific implications for left-right symmetric models are discussed.

show abstract

“…Also for the amplitudes in classes I-III we rely on the dispersion relation (33) to compute the HVP in the space-like region. This method was employed, for example, to compute the hadronic corrections to muon decay [84,85] and Bhabha scattering [86][87][88]. The hadronic NNLO corrections to μ-e scattering based on the R ratio were presented in [65].…”

Section: Next-to-next-to Leading Ordermentioning

confidence: 99%