==== HJ/HH/ZH/H* Mass Scheme Uncertainties ====

**Project Description**

Study of top-quark mass scheme uncertainties (MSbar/OS) in Higgs processes:
  * HH (LO/NLO)
  * HJ (LO/NLO asymptotic expansion)
  * ggHZ vs ggZZ (LO)
  * H* (LO/NLO)

Open Questions:
  * How are these various processes affected by the mass scheme uncertainty?
  * To what extent is this problem coming from "Triangle-type" topologies vs "Box-type" topologies? (See for example expanded result of Steinhauser et al.)
  * Can we say anything about what is a sensible (or not sensible) choice of scheme?
  * Should we be treating masses running in the loops differently from those entering the Yukawa couplings?
  * How much of this behaviour is due to the mass dependence of the Yukawa vs. top quarks in loop?
  * How large is this uncertainty in the context of the onshell/ofshell Higgs measurements?


** References **
  * [[https://arxiv.org/abs/1811.05692| Gluon fusion into Higgs pairs at NLO QCD and the top mass scheme
]]
  * [[https://indico.cern.ch/event/825291 |Slides (Michael Spira), 17 June]]
  * [[https://arxiv.org/abs/1709.01092|High-Energy Limit of QCD beyond Sudakov Approximation]]
  * [[https://arxiv.org/abs/1809.04950|High-Energy Limit of Mass-Suppressed Amplitudes in Gauge Theories]]
  * [[https://arxiv.org/abs/1811.05489|Double Higgs boson production at NLO in the high-energy limit: complete analytic results]]
  * [[https://arxiv.org/abs/1712.06549|Two-loop amplitudes for processes gg→Hg,qg→Hq and qq¯→Hg at large Higgs transverse momentum]]


**Interested Participants**
  * Javier Mazzitelli
  * Daniel de Florian
  * Stephen Jones
  * Michael Spira
  * Xuan Chen
  * Raoul Röntsch
  * Joey Huston
  * ...