
Karma 6
2
Posted by eno •
2
Posted by eno •
d_sigma
, yes, that can happen, even though we would usually regard this value as a probability for the event to happen. But it's a bit more complicated than this in practice. The negative values here come from the so-called parton density function, which can become negative (at higher orders in perturbation theory). Note that this is only a statement about individual points in the sample. Overall, with enough statistics, you will always get a positive sigma
for any meaningful physics observable.2
Posted by eno •
2
Posted by eno •