Institute for Theoretical Particle Physics (TTP)


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preprints:2008:ttp08-26 [2016/03/17 11:03] (current)
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 +====== TTP08-26 Two-loop QED hadronic corrections to Bhabha scattering ====== 
 +   <hidden TTP08-26  Two-loop QED hadronic corrections to Bhabha scattering > heoretical predictions for Bhabha scattering at the two-loop level require the inclusion of 
 + hadronic vacuum polarization in the photon propagator. We present predictions for the contri 
 + butions from reducible amplitudes which are proportional to the vacuum polarization $\pi(q^2 
 + )$ and from irreducible ones where the vacuum polarization appears in a loop representing ve 
 + rtex or box diagrams. The second case can be treated by using dispersion relations with a we 
 + ight function proportional to the $R$-ratio as measured in electron-positron annihilation in 
 + to hadrons and kernels that can be calculated perturbatively. We present simple analytical f 
 + orms for the kernels and, using two convenient parametrizations for the function $R(s)$, num 
 + erical results for the quantities of interest. As a cross check we evaluate the correspondin 
 + g corrections resulting from light and heavy lepton loops and we find perfect agreement with 
 +  previous calculations. For the hadronic correction our result are in good agreement with a 
 + previous evaluation. 
 + </hidden> 
 +|**Johann H. K&uuml;hn and Sandro Uccirati**  |  
 +|**  Nucl.Phys.  B806 300-326 2009  **  | 
 +| {{preprints:2008:ttp08-26.pdf|PDF}} {{|PostScript}} [[|arXiv]]   | 
 +| |