December+3-December+9

Today, I arrived at 3:30 and continued work with the 100k event excel spreadsheet. Jason began by graphing phi values, so I started with eta. I first graphed 2000 events. Below is the scatter plot of the data. The data was still sorted by E/M. Hopefully, by manipulating the data that matched our E/M paramaters, we have narrowed down the window in which to find cosmic rays.

I noticed on plot that just after event 1000, the data switches from being concentrated to generally around an eta value of 0 to being scattered across the board. Incidentally, Jason had simultaneously narrowed his data to event 1055 in a similar way; he noticed that there was a differentiation of phi values at negative and positive 1/2 pi on phis 1 and 2, respectively, below 1055, but a general scattering above 1055.

Below are my graphs of phi.

I then graphed eta 1 up to this value to see if it, too, eliminated the clustered events and kept only the ones with the trend in which we are interested. It seems to have worked; the remaining events show a concentration around 0. The fact that these events meet both the phi and eta paramaters of cosmic rays in addition to E/M is conclusive evidence that these are cosmic rays.

As a group, we discussed the relationship of E/M in relationship to Phi1+Phi2, and we discussed where on a graph we would expect to find cosmic rays if we plotted them against each other. Because the E/M value for cosmic rays is about 1, and the Phi1+Phi2 value of cosmic rays is about 0, we would expect a cluster around (0,1).