I arrived in Durham on June 16th and immediately ran into some problems with my apartment. There was no one there to give me the keys like I had been promised. So after waiting for 45 minutes in the not so chilly 97 degree weather, I called a cab and checked into a hotel for the night. At least I met a really nice Venezuelan Duke student, who lives across from me.
But that was not the only problem I encountered with my apartment. When I went to the general office I learned that I am living illegally at this apartment complex, because the sublease was not properly communicated with them. They told me I had 48 hours to vacate the premises. Instead I just waited out my two days and they did not seem to care when I went back to the office. I'm still trying to sort that mess out, but at least it looks like I'm not going to be evicted any time soon, which is nice.
As for the actual lab I've had a bit of a slow start, but these past few days I have really done a lot. On June 18th I met a British postdoc, Chris, who helped me sign up for computer access and a Duke card, with which I can enter all the facilities on campus. From then on I was by myself, since neither of my PI's (I'm not sure yet who I'm going to work with the most) was in the country yet. So I basically just did some more research and reading on my own until I met Dr. Nahrgang on Monday. She and my other PI are both German, so I'm looking forward to the world cup final between Germany and the Netherlands on July 13th already (Yes I'm calling it right now). Dr. Nahrgang has set me up with my first set of assignments this week.
My lab is all about the study of Quark-Gluon Plasma, which is a (sort of) phase of matter, in which even the smallest pieces of matter (Quarks and Gluons) have no forces acting upon them. It is believed that in the first few microseconds after the big bang the entire universe was in a state of Quark Gluon Plasma. One reason why the subject Quark-Gluon Plasma is so interesting is because of the fact that it has never been observed, it only exists in theory. Apart from the requirement of a multibillion-dollar particle collider, this is the reason that my lab only creates and uses computer models to simulate particle collisions. These collisions give us data that can be used as evidence for the existence of Quark-Gluon Plasma. The phenomena that are evidence are called observeables, since we can not actually observe the plasma. Dr. Nahrgang started out by giving me a file, which contained the output of one of the computer models. In this file there were about 10 million lines of text, each containing the movement in x,y and z space of a quark, and its energy. Opening up this file containing 40 million numbers with 10 decimal places would take about two ages on my laptop, so she gave me the first 100.000 lines of data. For the first observable, we would like to be able to distinguish between particles that hardly interacted and particles that went flying all over the place. To do this we calculate the pt of each particle. This basically is the movement of the particle in the x,y plane. So when we have a beam of particles firing straight at us, we look head-on how the particle scatters after a collision with another particle. We take the x and y component of that scatter and take the hypotenuse, which is called pt. A high pt particle has interacted a lot with other particles, and therefor is more interesting than a low pt particle which might have only clipped another particle, or not even hit something at all.
This is the pt distribution of 100.000 particles in a histogram. It shows the number of events per level of pt (in GeV)
The mass of this certain kind of particle can also be found with the formula: square root(energy^2 - pt^2 - movementZ^2). For this particle (bottom quark), I found a mass of 5.0 GeV. All of these calculations have been done in a computer program that I created, and the graphing tools are built-in the programming language.
Finally, I also have a cool picture of the particles scattered after the collision in 3D space:
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