TY - JOUR
T1 - Modified contour-improved perturbation theory
AU - Cvetič, Gorazd
AU - Loewe, Marcelo
AU - Martinez, Cristian
AU - Valenzuela, Cristián
PY - 2010/11/12
Y1 - 2010/11/12
N2 - The semihadronic tau decay width allows a clean extraction of the strong coupling constant at low energies. We present a modification of the standard "contour-improved" method based on a derivative expansion of the Adler function. The new approach has some advantages compared to contour-improved perturbation theory. The renormalization scale dependence is weaker by more than a factor of 2 and the last term of the expansion is reduced by about 10%, while the renormalization scheme dependence remains approximately equal. The extracted QCD coupling at the tau mass scale is by 2% lower than the contour-improved value. We find αs(MZ2)=0.1211±0.0010.
AB - The semihadronic tau decay width allows a clean extraction of the strong coupling constant at low energies. We present a modification of the standard "contour-improved" method based on a derivative expansion of the Adler function. The new approach has some advantages compared to contour-improved perturbation theory. The renormalization scale dependence is weaker by more than a factor of 2 and the last term of the expansion is reduced by about 10%, while the renormalization scheme dependence remains approximately equal. The extracted QCD coupling at the tau mass scale is by 2% lower than the contour-improved value. We find αs(MZ2)=0.1211±0.0010.
UR - http://www.scopus.com/inward/record.url?scp=78651100599&partnerID=8YFLogxK
U2 - 10.1103/PhysRevD.82.093007
DO - 10.1103/PhysRevD.82.093007
M3 - Article
AN - SCOPUS:78651100599
SN - 1550-7998
VL - 82
JO - Physical Review D - Particles, Fields, Gravitation and Cosmology
JF - Physical Review D - Particles, Fields, Gravitation and Cosmology
IS - 9
M1 - 093007
ER -