Week+of+March+11-+March+18

March 11
Today I arrived at Quarknet at 3:30 and reviewed my most recent post. It seems that I had found the reason that the momentum readings had seemed a bit excessive for the assumed 0 momentum, and I found that, by graphing other events, that the momentum readings we were getting were in fact, very close to 0, which is what we want. I can come to the conclusion that these momentum readings exist due to the fact that the cosmic rays cannot physically be shooting exactly straight through the detector, simply because that is an unreasonable assumption, as slight curvature in the cosmic ray is inevitable even due to interaction with its surroundings. What effectively proves this is the fact that the solenoid magnetic field is extensive enough such that the large, heavy, highly momentum particle (cosmic ray) will bend enough to pick up a slight curvature. Not to mention, I have no knowledge in the accuracy of the detector's measurement devices. It could simply be that there is just a slight amount of error that causes momentum readings to come forth.

After talking with Dr. Loughran for a good while about the headway that I have made in the past week, we have come to many conclusions. First off, the Q1*Q2 and/or mass question that I had was as follows:

I was curious as to why these small particles still remained in the dataset. It seems that I should have eliminated them previously when I cut the positive Q1*Q2 values. To solve this, I will simply make this cut, and the question will be solved.

Now that I have cut those particles out of the data, I can proceed with the next questions that I have obtained. The first question that I have discussed with Dr. Loughran is that regarding the momentum in various directions within the detector. The momentum in the y-direction exists as the energy of the cosmic ray coming down and penetrating the detector is evaluated, and the energy is clearly proportional to momentum by the equation E^2 = M^2 + P^2. I originally assumed that the momentum should read 0, but I can conclude that it should not be zero, and this was reinforced by the data: One thing notable about this plot is the heavier density of particles on the negative side. This is due to the cosmic ray coming downwards. One thing that I was curious about that I discussed with Dr. Loughran is the idea that a cosmic ray could possibly fail to be recording on the upper side of the detector due to the particle coming down from outside. If the muon contacts the opposite side of the muon chambers, does this impact the way it is recorded? Does this position at a phi value of pi/2 result in a different reading than that of 3pi/2? I would like to look at the makeup of these muon detectors to see how they should respond to a particle entering from the opposite way. The next piece that we discussed is that of momentum in the x-direction. Again, I made the mistake of thinking that the px should be zero, when in reality, momentum has to exist in the x direction that the detector will receive. By the ray entering with its magnitude an direction as a vector, this does allow for momentum to be recorded. Imagine a right triangle with the hypotenuse as the cosmic ray vector. The bottom leg would be the px value. Thus, if the magnitude (mass*velocity) of the cosmic ray increases, as does the momentum in the x-direction.This information is represented in the graph of the momentum in the x-direction: As can be seen, the momentum values increase and decrease at a seemingly random spread. This is understandable as the larger magnitude momentum values would simply have a greater momentum. With such great energy in these cosmic rays, the momentum in the x-direction cannot be ignored.