October+29-November+4

October 29
I arrived at 3:30 and left at 5:30 today. I spent my time analyzing the plots that I found in ManyEyes.

[[image:sjhsrc/py1 vs px1.png width="800" height="409"]]
This graph first stood out to me because of its generally circular shape. The dot size still reflects mass, and we see the larger dots on the outside of the circular mass of the graph. The x and y axis represent momentum in the x and y directions, respectively. This shows that the heavier particles moved with the most momentum in both directions. These high-energy particles have the characteristics of cosmic rays.

2.


The most notable aspect of the graph above is the linear grouping of particles that emerge from the clump. While the smaller, less massive particles tend to concentrate closer to zero on the x axis, representing energy of the second particle, a group of larger dots (more massive particles) extends in a linear pattern, showing more momentum and a greater energy. The fact that so many of them cluster on this graph (retained similar momentum and energy) suggests that they are all the same type of particle--a particle that differs from the scattering, less-massive particles.

3.
I noted this graph initially for its distinct shape; there are two definite asymptotes giving the graph a sort of rotated "V" shape. The more massive particles, though, emerge from the middle of this "V." At first, I thought that the two lines that form the "V" might reflect particles 1 and 2 from each dimuon pair, but with further thought and more experimentation on the ManyEyes website, I changed my mind. The significance in this graph lies in that the energy as well as the momentum of particles 1 and 2 of the more massive pairs even out to the middle of the "V" shape.

4.
This graph, beginning at a mass of 40 GeV (the point at which we have seen cosmic rays begin in the past), shows a linear trend. The more massive particles have a greater momentum in the x and y directions.

5.
I was having trouble interpreting the above graph (pz1 vs. eta1), so I went back to ManyEyes, separated the most massive particles in a different window (eta1 vs. Mass), highlighted them, and then returned to this graph. The most massive particles followed a linear trend, shown below, while the smaller particles tended to hover around the line pz1=0. I then tired to think of this data in terms of eta. This line of massive particles represents a vertical line of particles entering the detector in a straight line toward the center. The absolute value of the larger particles' momentum (pz1) is greater than that of the smaller ones.

[[image:e v. pz.png width="800" height="407"]]
There is an obvious trend beginning at an energy sum of 40. This line of large and energetic particles (cosmic rays) emerges from the cluster of smaller ones. Also, there is a horizontal line of particles at around an energy of 90 that are presumably z bosons.

October 31
Today I arrived at 3:45 and discussed our next project with Jason and Dr. L. Once we have finished analyzing ManyEyes graphs, we will be working in Excel. Our task is to pull the CSV file into Excel, create a new column of (E1+E2)/M, sort the data, and isolate cosmic rays based on the ratio. Until John provides us with the link, though, we will continue analyzing the ManyEyes plots.

[[image:E1 vs E sum parent rest frame.png width="800" height="407"]]
Here is another example of the most massive and energetic particles in a linear trend starting at 40 GeV on the x axis. They emerge from the cluster of smaller particles and are presumably cosmic rays. Additionally, around 90 GeV we see another cluster, presumably z bozons. A similar graph is produced when the X axis reflects the E2 parent rest frame.

8.


These two graphs are similar; they both have the notable quality: similar to E sum parent rest frame vs. pz sum, of a linear grouping of large particles emerging from a cluster of smaller particles beginning at 40 GeV. Again, at 90 GeV, there is a horizontal grouping of particles that we can assume are z bozons because they tend to possess that mass.

[[image:aslkdjfld.png width="800" height="410"]]
The particles on this graph all remain above the line E sum =p 3d resultant. Energy can never be less than momentum ("p" in this case) because the value of momentum squared plus the value of the mass squared is equal to the energy squared. (E^2=m^2+p^2). The most massive particles on this graph collect along the y-axis (at p 3d resultant=0). This is probably because the detector interpreted a single particle (cosmic ray) travelling straight through the detector as two dimuon particles acting opposite of each other, so their value "cancelled out."

10.


In the first graph, M parent rest frame vs. pt1, the linear grouping of particles (follows the line M parent rest frame = 2pt1) emerges from the cluster of smaller particles at a value of 20. There is also a grouping of particles along the horizontal line M parent rest frame= 90, again probably z bozons.



When the y-axis is switched to reflect E sum parent rest frame, the graph does not change. This remained to be the case any time the x-axis stood for momentum (px, pz, pt, py). That is, the values for E sum parent rest frame and M parent rest frame on the y-axes were the same. This shows the relationship between mass and energy for the particles; at the point at which these particles are interacting, their mass equals their energy.