There is one difference in conditions for pulse head versus pulse tail - pulse head hits way cooler target material than the tail. The question is whether there is a difference or not. But if there is any, I'd expect the head to be somewhat "sharper", less blurred than the tail. But of course I have no idea what the temperature change on the duration of the pulse is.adam_jeff wrote:But so far, no-one seems to have suggested a mechanism that would mean there are more neutrinos sampled from the front of the pulse than the end.
The 60 ns difference is almost invisible on these graphs. These are for the "initial match" where they had the CERN BCT off by about a microsecond, that's why there's "1048.5 ns". Sure the match used all the pulse width, but internal differences are not all that great, it's edges what drives most of the match.adam_jeff wrote:Another thing to consider: most of the analysis so far has concentrated on the edges of the pulse (which are most important from the timing point of view). But the whole pulse is measured, and if there was a skew like you suggest there would be a slope on the measured profile compared to the one which is sent. There isn't, as shown in the graphs below.
That's why I think they should try measuring with LHC beam for a while, similar to what they used to align their BCTs. LHC beam has ~10 ns pulses, that's nothing but edges at their resolution. They can get much better fit on these even if they recognize only a handful of neutrinos from background.