Elite Science Student Visit Abroad Program (ESSVAP)

Hidetoshi Taya (Physics)

Norman Christ

Norman is a specialist in lattice QCD and is famous for his collaboration in some supercomputer projects, for example, Quantum Chromo Dynamics on Digital Signal Processors(QCDSP) Project.

I attended one of Norman's seminars for graduates, which was about the introduction of the laboratory. I heard that there are such kind of seminars throughout the year in CU because graduate students in CU do not belong to a particular laboratory at the time of entering graduate school as in UT.

In the seminar, Norman gave us an introductory lecture about lattice QCD and then introduced some research topics in his laboratory: properties of K meson, spectral analysis of a Dirac operator, etc.

We also had a talk in the welcome party. Unfortunately, the time was so limited that I failed to make it useful, but Norman's kindly smile was really impressive.

Bill Zajc

Bill is an experimental nuclear physicist specializing in high energy collisions of heavy ions and was the spokesperson for the PHENIX experiment at Brookhaven National Laboratory's (BNL) Relativistic Heavy Ion Collider (RHIC).

I asked mainly about the experimental progress at RHIC, especially focusing on Quark Gluon Plasma(QGP), and had a really impressive talk. We talked many topics: technical topics such as J/Psi suppression, HBT effect, Chiral Magnetic Effect, etc. and more general topics such as the future of the high energy physics. So I just skip each detail here, but basically I strongly realized the experimental difficulties and necessity of the progress in both theory and experiment.

Miklos Gyulassy

Miklos is the principal investigator of the nuclear theory group in CU and is mainly studying about the physics of QGP.

What is distinct in his recent research is the application of AdS/CFT correspondence from String Theory as a new theoretical tool and so I asked some related questions. Actually, String Theory made some remarkable successes such as the calculation of the viscosity of QGP produced at RHIC, which is impossible for the present gauge theory, but, on the otherhand, there is still many problems to be solved so that further progress is expected in the future. One of the most impressive Miklos's statements, I forgot the exact words he used but I think the meaning was basically the same, was "The physics, for example, appearing in textbooks is boring because it is already cleaned up. Physicists must study physics as if struggling in the mud and such dirty part is the really interesting part of physics." This "muddy" attitude must be the reason why Miklos dare use String Theory, which is not established enough yet.

While Miklos uses String Theory, which is a highly mathematical theory, it was also impressive that Miklos places great importance on existing experiments. In fact, Miklos said that why he chose to study QGP among rich topics in hadron physics was the abundance of the experimental data. Such attitude is, I believe, indeed essential since theory is by no means a fantasy and, at the same time, I thought that it is also an important task for theorists to propose new experiments for the region where the present experiments are not applicable.

We also talked about the education in UT. Miklos said that it is difficult to educate every graduate student in the most efficient way in graduate school in the US because each student's knowledge differs widely. This is because each student is coming from all over the world and the education differs widely in each country. I suppose this, I do not know whether it is good or not, must be one of the reasons why many graduate courses in the US looks quite easy for UT undergraduates.

Brookhaven National Laboratory (BNL)

BNL, located about 100km east of Manhattan, is the world's leading laboratory for high energy physics. Great discoveries such as CP-violation made at BNL have won 5 Nobel Prizes in physics. Recently, RHIC, one of the world's most important experiments in physics, is running at BNL and so I made an appointment with Taku Gunji, Center for Nuclear Study(CNS), to visit RHIC/BNL.

What I have to mention first is the security at BNL. It was really tight as at PPPL. Actually, it took me about a whole month to get the admission, and a number of trainings are required for each person depending on one's activity. I was impressed with this sophisticated crisis management in the US.

When I got there, I was really surprised at the huge site, and so one needs a car to get around in BNL. In the huge site, there are many kinds of laboratories, not only for high energy physics like RHIC, but also for nanomaterial, medicine, etc. Originally, BNL's main research field is only high energy physics, however, such "practical" research is getting increased, and so there are many related laboratory buildings under construction.

After driving round RHIC ring (~4km), I visited PHENIX control room. Since this is my first time to see such "big" experiment actually working, everything – the number of people working, huge equipments, etc. – was fresh for me. At the same time, I found a large number of Japanese were working there. This might be one of the appearances of the strong contribution of Japan to science.

I discussed RHIC physics with the scientists in the room using the actual equipments and data and it was really meaningful. I again realized the experimental difficulties and necessity of the progress in both theory and experiment.