No, but they had enough neutrinos.
It was a bad example on my part, actually. I was just saying something that gives a higher chance to stop a neutrino (but it'd still be a very low chance). There's this cute example calculation to put the low cross section into perspective, and it usually goes that you'd need to fill the entire solar system with lead to stop one.
However, actual detection involves interaction, of course. You can try to get a reaction "derived" from beta decay (though that only works with electron neutrinos), or something similar. The actual detection process is notoriously difficult, of course.
For more on the subject, here's wikipedias article on the
subject.
Take this from the
press release (which is written in a way that should be understandable even if you don't have all the basics down):
The OPERA result is based on the observation of over 15000 neutrino events measured at Gran Sasso, and appears to indicate that the neutrinos travel at a velocity 20 parts per million above the speed of light, nature’s cosmic speed limit.
Note that the
relative differente to c is very small.
This whole thing, however, isn't so much about the detection of the neutrinos, but rather about the time it took them to travel through part of the earth (which I suppose you knew already, but I want an excuse to post this):
In order to perform this study, the OPERA Collaboration teamed up with experts in metrology from CERN and other institutions to perform a series of high precision measurements of the distance between the source and the detector, and of the neutrinos’ time of flight. The distance between the origin of the neutrino beam and OPERA was measured with an uncertainty of 20 cm over the 730 km travel path. The neutrinos’ time of flight was determined with an accuracy of less than 10 nanoseconds by using sophisticated instruments including advanced GPS systems and atomic clocks. The time response of all elements of the CNGS beam line and of the OPERA detector has also been measured with great precision.
