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Article
Report number	arXiv:1912.05943 ; MPP-2019-254
Title	Photon pair production in gluon fusion: Top quark effects around threshold
Author(s)	Chen, Long (Munich, Max Planck Inst.) ; Heinrich, Gudrun (Munich, Max Planck Inst.) ; Jahn, Stephan (Munich, Max Planck Inst.) ; Jones, Stephen P. (CERN) ; Kerner, Matthias (Zurich U.) ; Schlenk, Johannes (PSI, Villigen) ; Yokoya, Hiroshi (Korea Inst. Advanced Study, Seoul)
Publication	SISSA, 2019-12-12
Imprint	2019-12-12
Number of pages	11
Note	10 pages, 4 figures. Contribution to the 14th International Symposium on Radiative Corrections (RADCOR2019), 9-13 September 2019, Palais des Papes, Avignon, France
In:	PoS RADCOR2019 (2019) 026
In:	14th International Symposium on Radiative Corrections : Application of Quantum Field Theory to Phenomenology, Avignon, France, 8 - 13 Sep 2019, pp.026
DOI	10.22323/1.375.0026
Subject category	hep-ex ; Particle Physics - Experiment ; hep-ph ; Particle Physics - Phenomenology
Abstract	We present a calculation of the NLO QCD corrections to the loop-induced production of a photon pair through gluon fusion, including massive top quarks at two loops. The two-loop virtual amplitudes are computed via projecting onto a set of Lorentz structures related to linear polarisation states of external gauge bosons. All two-loop master integrals dependent on the top quark mass are evaluated numerically. Matching the fixed order NLO result to a calculation with threshold resummation, we obtain an accurate description of the diphoton invariant mass spectrum around the threshold of top quark pair production. We analyse how the distribution of the diphoton invariant mass is affected by the top quark loop-induced corrections, especially around the top quark pair production threshold.
Copyright/License	preprint: (License: arXiv nonexclusive-distrib 1.0) publication: © 2020-2024 The authors (License: CC-BY-NC-ND-4.0)

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