{ "id": "hep-ph/9703268", "version": "v2", "published": "1997-03-07T17:44:25.000Z", "updated": "1997-07-08T08:12:20.000Z", "title": "Resummation analysis of the $τ$ decay width using the four-loop $β$-function", "authors": [ "S. Groote", "J. G. Körner", "A. A. Pivovarov" ], "comment": "12 pages, LaTeX, more detailed explanation of the analysis done for the determination of the convergence radius, one PostScript figure added", "journal": "Mod.Phys.Lett. A13 (1998) 637-650", "doi": "10.1142/S0217732398000693", "categories": [ "hep-ph" ], "abstract": "We extract the strong coupling constant $\\alpha_s(m_\\tau^2)$ from the semileptonic $\\tau$ decay width taking into account resummation effects from the running of the strong coupling constant. In the $\\overline{\\rm MS}$ scheme the result reads $\\alpha_s=0.375\\pm 0.007$ to third order and $\\alpha_s=0.378\\pm 0.007$ to fourth order in the $\\beta$-function, respectively, where we use the recently computed four-loop coefficient $\\beta_3$. These values for the coupling constant have to be compared with the value $\\alpha_s=0.354\\pm 0.005$ derived from a third order analysis of $\\tau$ decays. We determine the exact value of the convergence radius of the perturbation series by analyzing the singularity structure of the complex coupling constant plane.", "revisions": [ { "version": "v2", "updated": "1997-07-08T08:12:20.000Z" } ], "analyses": { "keywords": [ "decay width", "resummation analysis", "strong coupling constant", "account resummation effects", "complex coupling constant plane" ], "tags": [ "journal article" ], "note": { "typesetting": "LaTeX", "pages": 12, "language": "en", "license": "arXiv", "status": "editable", "inspire": 441015 } } }