Exercise 1 Answers

Event: 2, 7, 10, 17, 30, 36,

It is easier if you work with HYPATIA 4 and load the 7 events of the file called "conservation".There the evnts have only few tracks and you can add the momenta vectorially. Then check if the vector which is equal but opposite to the vector sum agrees more or less with the quanity marked on the right (under the window of the histograms) as "Etmiss".The smaller this quantity is the less momentum is unbalanced by the tracks. The event with smaller Etmiss is #7.The reasons why Etmiss is not zero can be the following:neutrinos produced which escape undetected and in lesser extend:energy gone in detector cracks,limiting accuracy of the measurements, etc