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Sep 22, 2013
09/13

by
Thomas Gehrmann; Gionata Luisoni; Pier Francesco Monni

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In the context of the dispersive model for non-perturbative corrections, we extend the leading renormalon subtraction to NNLO for the thrust distribution in $e^+e^-$ annihilation. Within this framework, using a NNLL+NNLO perturbative description and including bottom quark mass effects to NLO, we analyse data in the centre-of-mass energy range $\sqrt{s}=14-206$ GeV in view of a simultaneous determination of the strong coupling constant and the non-perturbative parameter $\alpha_0$. The fits are...

Source: http://arxiv.org/abs/1210.6945v2

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6.0

Jun 29, 2018
06/18

by
James Currie; Thomas Gehrmann; Jan Niehues

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The production of two-jet final states in deep inelastic scattering is an important QCD precision observable. We compute it for the first time to next-to-next-to-leading order (NNLO) in perturbative QCD. Our calculation is fully differential in the lepton and jet variables and allows one to impose cuts on the jets both in the laboratory and the Breit frame. We observe that the NNLO corrections are moderate in size, except at kinematical edges, and that their inclusion leads to a substantial...

Topic: High Energy Physics - Phenomenology

Source: http://arxiv.org/abs/1606.03991

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4.0

Jun 28, 2018
06/18

by
Taushif Ahmed; Thomas Gehrmann; Prakash Mathews; Narayan Rana; V. Ravindran

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The coupling of a pseudo-scalar Higgs boson to gluons is mediated through a heavy quark loop. In the limit of large quark mass, it is described by an effective Lagrangian that only admits light degrees of freedom. In this effective theory, we compute the three-loop massless QCD corrections to the form factor that describes the coupling of a pseudo-scalar Higgs boson to gluons. Due to the axial anomaly, the pseudo-scalar operator for the gluonic field strength mixes with the divergence of the...

Topics: High Energy Physics - Experiment, High Energy Physics - Phenomenology

Source: http://arxiv.org/abs/1510.01715