Discussion Overview
The discussion revolves around the divergence of the 2gNNLO prediction in the context of small diphoton transverse momentum (qt) and the application of the qt-subtraction formalism to address infrared (IR) divergences. Participants explore the implications of this divergence and its relation to phase space considerations.
Discussion Character
- Technical explanation, Debate/contested
Main Points Raised
- One participant notes that the qt-subtraction formalism is intended to cancel IR divergences in small diphoton transverse momentum but expresses confusion about the divergence of the 2gNNLO prediction in this region.
- Another participant questions whether the original inquiry pertains to a specific figure (Fig. 1b) in the referenced paper.
- A different participant observes that the 2gNNLO prediction appears to deviate significantly from data, suggesting it is off by 2-3 standard deviations across the diphoton pT spectrum, particularly in comparison to the SHERPA model.
- One participant proposes that the qt-subtraction formalism is akin to phase space slicing and discusses the need for soft gluon resummation in the context of the divergence related to qt approaching zero, linking it to specific reaction processes.
Areas of Agreement / Disagreement
Participants express differing levels of understanding regarding the divergence issue, with some questioning the applicability of the qt-subtraction formalism and others pointing out discrepancies between predictions and experimental data. No consensus is reached on the underlying reasons for the divergence.
Contextual Notes
The discussion highlights the complexity of the phase space involved in the reactions being analyzed and the potential need for additional techniques, such as soft gluon resummation, to address the divergences observed.