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arXiv · 1710.03724

Life of Π

Andreas Maier·Peter Marquard
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Abstract

The heavy-quark contribution to the polarisation function $Π$ at higher perturbative orders is presently only known approximately. We scrutinise the accuracy of state-of-the-art approximations at three- and four-loop order. At three loops, we present for the first time a result with arbitrary numerical precision for general kinematics and compare to the best Padé estimate. At four loops, we calculate the fourth (inverse) moment of the non-singlet heavy-quark vacuum polarisation in order to test the prediction for this moment based on Padé approximation.

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Andreas Maier, Peter Marquard. 2018-04-09. Life of Π. https://doi.org/10.1103/physrevd.97.056016

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