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+ | ====== TTP08-26 Two-loop QED hadronic corrections to Bhabha scattering ====== | ||

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+ | <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. Kühn and Sandro Uccirati** | | ||

+ | |** Nucl.Phys. B806 300-326 2009 ** | | ||

+ | | {{preprints:2008:ttp08-26.pdf|PDF}} {{preprints:2008:ttp08-26.ps|PostScript}} [[http://arxiv.org/abs/0807.1284|arXiv]] | | ||

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