The ICARUS experiment, like the Cohen-Glashow paper on which they rely, are claiming again to “refute” the OPERA experiment on superluminal neutrinos. (I already wrote about that here.) I’m sympathetic, personally, but although it does provide a very strong constraint on any modification of relativity that could permit what OPERA observes, logically this does not, in my current view, constitute a refutation.
What Andrew Cohen and Sheldon Glashow of Boston University pointed out (as explained in detail in this post) is that if neutrinos traveled faster than light there would be an effect similar to Cerenkov radiation that would reduce the energy of the neutrinos in OPERA’s neutrino beam — an effect OPERA would have seen, but did not. ICARUS is simply confirming this: that the beam of neutrinos from CERN, which it too can measure (it is quite close to OPERA) shows no sign of the neutrinos having lost energy.
The problem is that logically Cohen-Glashow and ICARUS only prove that either OPERA is wrong or there’s a so-far unknown modification of relativity which allows an escape from Cerenkov-type radiation for neutrinos at the energies of OPERA’s beam. It is certainly true that Cohen-Glashow makes OPERA even less plausible than it was before, but it does not settle the issue. Since OPERA calls a deep theoretical assumption about relativity into question, it is not a great idea to refute it using another set of theoretical assumptions about relativity that might simultaneously come into question.
So until someone proves that there’s absolutely no way to inhibit Cohen-Glashow radiation without violating some other existing experiment, we still, in my view, have to treat OPERA as deeply implausible but not strictly refuted.