The twistor string gave rise to “BCFW recursion relations” for gauge theories that are now the basis of many practical calculations, notably to model QCD processes at the LHC, the background against which anything new will be detected.
The Grassmannian reformulation of gauge theory in the new paper is a continuation of that research program, and the authors expect it to be generally valid—see page 137, third paragraph.
The only calculations I’ve seen referenced in actual releases from the LHC are either parton-shower calculated backgrounds (pythia), leading-order background (Madgraph,CalcHEP), or at most NLO (MCFM, etc). The automated NLO stuff will probably be soon done with BlackHat, which uses the standard unitarity method that Dixon and Kosower came up with to do the loops. So as far as experiments go, the BCFW relations aren’t really used to do QCD backgrounds. Please point me to a reference, if I’ve missed it.
I left physics for greener pastures after my postdoc and have been working as a statistician for a few years now, but certainly in the first several years of the BCFW recursions, people weren’t doing that much with them. A few fun results for pure gluon amplitudes that were difficult to integrate into the messy world of higher-order QCD calculations (how do you consistently parton-shower when your gluon processes are at all order, and your quark processes are at NLO?), and that was about it.
The most practical use of BCFW that I have found is in arxiv:1010.3991; if you read pages 3 and 4 closely, you’ll see that BCFW was used to construct N=4 amplitudes which were then transposed to QCD and used to calculate a “W + 4 jets” background. I take your point that, although there are theorists using BCFW to model LHC physics, including some from BlackHat, the LHC teams themselves still do their in-house calculations using other methods. Though I think of unitarity cuts as another part of the same big transformation as BCFW.
The twistor string gave rise to “BCFW recursion relations” for gauge theories that are now the basis of many practical calculations, notably to model QCD processes at the LHC, the background against which anything new will be detected.
The Grassmannian reformulation of gauge theory in the new paper is a continuation of that research program, and the authors expect it to be generally valid—see page 137, third paragraph.
The only calculations I’ve seen referenced in actual releases from the LHC are either parton-shower calculated backgrounds (pythia), leading-order background (Madgraph,CalcHEP), or at most NLO (MCFM, etc). The automated NLO stuff will probably be soon done with BlackHat, which uses the standard unitarity method that Dixon and Kosower came up with to do the loops. So as far as experiments go, the BCFW relations aren’t really used to do QCD backgrounds. Please point me to a reference, if I’ve missed it.
I left physics for greener pastures after my postdoc and have been working as a statistician for a few years now, but certainly in the first several years of the BCFW recursions, people weren’t doing that much with them. A few fun results for pure gluon amplitudes that were difficult to integrate into the messy world of higher-order QCD calculations (how do you consistently parton-shower when your gluon processes are at all order, and your quark processes are at NLO?), and that was about it.
The most practical use of BCFW that I have found is in arxiv:1010.3991; if you read pages 3 and 4 closely, you’ll see that BCFW was used to construct N=4 amplitudes which were then transposed to QCD and used to calculate a “W + 4 jets” background. I take your point that, although there are theorists using BCFW to model LHC physics, including some from BlackHat, the LHC teams themselves still do their in-house calculations using other methods. Though I think of unitarity cuts as another part of the same big transformation as BCFW.