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arXiv · 1607.00990

Precise top-quark mass from the diphoton mass spectrum

Sayaka Kawabata·Hiroshi Yokoya
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Abstract

We calculate the $gg\toγγ$ amplitude by including the $t\bar t$ bound-state effects near their mass threshold. In terms of the non-relativistic expansion of the amplitude, the LO contribution is an energy-independent term in the one-loop amplitude. We include the NLO contribution described by the non-relativistic Green function and part of the NNLO contribution. Despite a missing NLO piece which can be accomplished with the two-loop-level amplitude via massive quarks, the shape of the diphoton mass spectrum is predicted with a good accuracy. Thanks to the simple and clean nature of the observable, its experimental measurement can be a direct method to determine the short-distance mass of the top quark at hadron colliders.

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Sayaka Kawabata, Hiroshi Yokoya. 2017-06-01. Precise top-quark mass from the diphoton mass spectrum. https://doi.org/10.1140/epjc%2Fs10052-017-4884-8

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