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preprints:2008:ttp08-21 [2016/03/15 20:38] (current)
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 +====== TTP08-21 Precise Determinations of the Strong Coupling Constant ====== 
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 +<hidden TTP08-21 ​ Precise Determinations of the Strong Coupling Constant > Recent results for the 
 + cross section of electron-positron annihilation into hadrons and for the 
 + decay rates of the $Z$-boson and the  $\tau$-lepton into hadrons including 
 + ​corrections of order  $\alpha_s^4$ are reviewed. 
 + The consistency between two values ​ of $\alpha_s$ measured 
 + at vastly different energies constitutes 
 + a striking test of asymptotic freedom. 
 + ​Combining the results from $Z$ and $\tau$ decays 
 + we find $\alpha_s(M_Z)=0.1198 \pm  0.0015$ as one of the most precise and 
 + ​presently only 
 + NNNLO result for the strong coupling constant. 
 + </​hidden>​ 
 +|**J.H. K&​uuml;​hn** ​ |  
 +|**       Nucl. Phys. B (Proc.Suppl.) ​  ​181 ​ (2008) (141-145). ​ Contribution to "​PHIPSI08,​ International Workshop on e+e- collisions from  Phi to Psi." Frascati, Italy, 7-10 April 2008 **  | 
 +| {{preprints:​2008:​ttp08-21.pdf|PDF}} {{preprints:​2008:​ttp08-21.ps|PostScript}} ​  | 
 +| |