- probably the most complicated
- without full mass dependence:
- massless result in principle known (3j @ NNLO [Gehrmann, Remiddi 2000] [Gehrmann, Remiddi 2001])
- recomputed by Turin group [Badger, Krys, Moodie, Zoia 202?]
- requires tricks (see Tim’s talk [Engel, Signer, Ulrich 2021] [Engel 2023])
- Q: jettification at two-loop
- with full mass dependence:
- analytic: almost certainly not possible in the foreseeable future
- numeric: maybe..., reduction looks doable, DiffExp [Hidding 2020] / AMFlow [Liu, Ma 2022] for evaluation
- Q: requires good basis