| | |
| | |
Stat |
Members: 3645 Articles: 2'504'928 Articles rated: 2609
26 April 2024 |
|
| | | |
|
Article overview
| |
|
Strong coupling constant to four loops in the analytic approach to QCD | Aleksey I. Alekseev
; | Date: |
21 Nov 2002 | Journal: | Few Body Syst. 32 (2003) 193-217 | Subject: | hep-ph | Abstract: | The QCD analytic running coupling alpha_{an} which has no nonphysical singularities for all Q^2>0 is considered for the initial perturbation theory approximations up to four loop order. The finiteness of the analytic coupling at zero is shown to be a consequence of the asymptotic freedom property of the initial theory. The nonperturbative contributions to the analytic coupling are extracted explicitly. For all Q>Lambda they are represented in the form of an expansion in inverse powers of Euclidean momentum squared. The effective method for a precise calculation of the analytic running coupling is developed on the basis of the stated expansion. The energy scale evolution of the analytic running coupling for the one- to four-loop cases is studied and the higher loop stability and low dependence on the quark threshold matching conditions in comparison with the perturbative running coupling were found. Normalizing the analytic running coupling at the scale of the rest mass of the Z boson with the world average value of the strong coupling constant, alpha_{an}(M_Z^2)=0.1181^{+0.002}_{-0.002}, one obtains as a result of the energy scale evolution of the analytic running coupling alpha_{an}(M_tau^2)= 0.2943^{+0.0111}_{-0.0106} that is notably lower than the estimations of the coupling strength available at the scale of the mass of the tau lepton. | Source: | arXiv, hep-ph/0211339 | Services: | Forum | Review | PDF | Favorites |
|
|
No review found.
Did you like this article?
Note: answers to reviews or questions about the article must be posted in the forum section.
Authors are not allowed to review their own article. They can use the forum section.
browser Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; ClaudeBot/1.0; +claudebot@anthropic.com)
|
| |
|
|
|
| News, job offers and information for researchers and scientists:
| |