Category: Event

This was originally posted in the SMU CERN blog (http://blog.smu.edu/smucern). It’s reproduced here because I am the author! 🙂

What DOES a professor do during the summer months? I found it amusing – and, to be fair, a bit reminiscent of my own beliefs when I was a student – that several undergraduates at SMU thought I took the summer off. So, just what DOES a professor do during the summer?

It depends on the professor, but many of us devote ourselves to teaching classes and many devote ourselves to research. Of course, we mingle the disciplines a lot – just because you’re teaching doesn’t mean you aren’t thinking deep thoughts about physics, and just because you’re doing research doesn’t mean you aren’t ready to teach at a moment’s notice.

Tingting (left) and Aidan (right) discuss particle accelerator beam structure next to a full-scale model of the Large Hadron Collider.

For my own case, it’s been a lot of both. I am joined this summer by an SMU graduate student, Tingting Cao (featured recently in [1]). She has never worked on an experiment like ATLAS before. The sheer magnitude of things you need to learn to make sense of day-to-day ATLAS physics and activities is immense. Tingting’s devotion and enthusiasm have so far carried her a long way in this regard. However, as a professor it is incumbent upon me to insure that TIngting has all the tools she needs not only to answer questions, but to know how to ask lots of questions.

My post-doc, Aidan, has been instrumental in working with Tingting to discuss physics and to teach her how to write analysis software (using C++, the language du jour of big collider physics). One of the great traps of software is that you can spend so much time learning just how to do it, you forget why you’re doing it. In collider physics, there is an ever-present tension between making progress (by writing analysis code) and seeing “the big picture” (why you are writing code in the first place). Aidan and I have been working hard, with a lot of help from Tingting’s curiosity, to keep that tension at bay.

In the foreground, a “warm” quadrupole magnet (meaning it operates at room temperature, rather than the superconducting temperatures needed by the Large Hadron Collider). In the background, Tingting and I discuss how such magnets act to focus charged particles.

We recently used the Microcosm, a teaching and learning center at CERN (which Aidan will discuss in a separate post) to learn about particle physics hardware. For instance, we discussed how magnets are to electrically charged particles as lenses are to light: they steer and focus the beams so that they are right where you want them. Shown below is a quadrupole magnet – a magnet with two pairs of North and South Poles – which act to focus charged particles. You need a long sequence of these to control the size of the beam, and the care and skill that goes into building and coordinating such magnets is incredible.

It’s not always about the hardware. Sometimes, you just want to understand why subatomic particles like quarks lead not to single particles in your detector, but “jets” – cone-like sprays containing dozens of particles smashing into your tracking system, your energy readout system (“calorimeters”), and your muon system (needed to detect the less-interacting, heavy cousin of the electron – the muon). Tingting asked for a lecture about how you go from simple diagrams of quarks and leptons – “Feynman Diagrams” – to the complex signatures of particles in the ATLAS detector. Aidan and I spent over an hour going step-by-step through an example diagram, discussing all the physics we could. In fact, veterans of my “Modern Physics” class from last semester may recall a problem involving whether or not top quarks can bind together via the strong force [2]. Tingting asked about just that process, in the context of other kinds of quarks, and we discussed that very problem as part of the lecture.

Tingting and I discuss what different kinds of particles will look like in an ATLAS-like detector (photo by Aidan Randle-Conde).

Teaching doesn’t stop when the summer starts for those of us who do research in the summer, just as new ideas for physics papers and projects don’t stop when the teaching starts. Being a physicist sometimes demands both, and it makes the enterprise all the sweeter to know that it’s impossible to separate the doing from the learning.

[1] “Knowing the Hardware”, by Aidan Randle-Conde, SMU CERN Blog (http://blog.smu.edu/smucern/2010/07/knowing_the_hardware_1.html)

[2] Problem SS-13: “Top Mesons” (PHY 3305, Spring 2010) http://www.physics.smu.edu/sekula/phy3305/homeworksolutions010.pdf

This was originally posted in the SMU CERN blog (http://blog.smu.edu/smucern). It’s reproduced here because I am the author! 🙂

I made some promises to myself for the summer: not too much eating out, regular food shopping, and home-cooked meals. Switzerland and France are expensive places; for instance, a shopping bag containing some vegetables (a few peppers and tomatoes), fruit (apples and bananas), some cheese, milk, yogurt, baguette, and pasta runs close to 30-40 Swiss Franc (about $25-$35 U.S.). However, a single meal at a restaurant often runs AT LEAST this much.

Whipping this into something resembling a tasty meal takes some extra effort. Air conditioning is not common in Switzerland, unless the building is for business; running the stove for 30 minutes to make dinner means sweating through your clothes, with temperatures in the 80s and humidity at uncomfortable levels.

I’ve managed to stick close to my promise. My host and I have shared cooking duties over the past two weeks, including the meal shown below:

From top to bottom: artichokes (cooked in some oil and tomato); beans cooked with peppers, onions, garlic, and cream; and chicken paprikash (chicken sauteed in cream, onion, pepper, paprika, and garlic).

Of course, food means gathering – not just eating alone. A few of the SMU graduate students organized a Fourth of July cookout at a park near CERN and Meyrin, a residential community by the laboratory. There were burgers and sausages, pickles and condiments and even American chips (Doritos!). We were joined not only by SMU folk, but by friends and colleagues from other Universities, including nearby UT Arlington and far-flung New York University (NYU). Kids were present, too, which made the whole thing feel a lot more like a family gathering on the 4th and less like a bunch of work colleagues hanging out and tossing a frisbee.

Of course, sometimes you do eat out. It’s unavoidable. There is a budding tradition in the SMU CERN group of picking a new place on Friday night, someplace preferably where you can dine for less than 20-30 CHF and which can be added to the list of affordable but tasty restaurants in Geneva. This past Friday evening, we found ourselves at a small local chain of chicken restaurants with a limited but delicious menu. The most popular item at our table? The half-chicken, roasted, with fries and salade (demi-poulet avec pommes frites et salade).

This was originally posted in the SMU CERN blog (http://blog.smu.edu/smucern). It’s reproduced here because I am the author! 🙂

Physicists seem to have a reputation, self-made or otherwise, for discussing physics on writing surfaces that are . . . less than typical. The most common phrase for a quick, short, but somewhat accurate calculation is a “back-of-the-envelope calculation,” implying the nature of the writing surface: whatever is at hand.

In the CERN cafeteria, over mouthfuls of paella and sips of water, sometimes your discussion about contributions to electrically charged particle radiation demands a writing surface. The napkins were all used, no envelopes in sight, and suddenly my colleague (an SMU post-doctoral researcher named Aidan) said, “We can use this banana peel – it works quite well!” He began scribbling a diagram of radiation loss versus energy for a few processes, writing in swift, smooth strokes on the waxy but rough surface of the banana peel. Believe it or not, it does make a FABULOUS writing surface!