In Their Own Words with Top Junior Investigator Kent Paschke

Kent Paschke
Kent Paschke

I grew up in Yuba City, Calif., which for various reasons, had been rated among the worst places to live in the country. It wasn’t so bad for me; one of the best things that happened to me there was meeting the girl who would later become my wife, Barbara.

My dad was a field scientist for the Department of Agriculture and my mom was always entertained by science, so I grew up with a sort of "Gee whiz!" attitude toward it. We had a small farm with cows and horses. Although I didn't exactly grow up doing morning chores, there is, indeed, a photo of my best man and me mucking out the horse stalls on the morning of my wedding.

I went to the University of Houston and ended up majoring in physics. Coming from small-town Yuba City, it took me about a year to adjust to the larger, more cosmopolitan Houston. I had the same experience of adjusting when I went from Houston to Carnegie Mellon for my graduate work, although I really liked the snow a lot.  I initially found my grad school classes quite difficult; I'd been able to sail through my undergraduate classes without trying too hard. I'd been fortunate enough to get a position with the nuclear physics group at Carnegie Mellon, working at Brookhaven, during the summer before I started classes. I think of that as the period when I was "learning to learn physics."  I’ve always found experimental work to be fun.

I did my thesis work at CERN, finished the analysis at Carnegie Mellon, and then came to Jefferson Lab for my postdoc work in parity violation.  I like the combination of topics this field addresses, including topics in QCD. The dynamics of the strong force seems, to me, to be an under-appreciated topic in fundamental physics.

Scientist's Research Links to the Stars

To physicists, lead bears a remarkable resemblance to a neutron star. Although the average neutron star is about twice as big as Earth and twice as heavy as our sun, they are all built of the same parts and bound by the same force as the lead nucleus. The humble lead nucleus is also comparable in density to a neutron star and is composed of a large fraction of neutrons, so understanding how heavy nuclei like lead are put together is crucial for understanding neutron stars.

Soon, Kent Paschke and his colleagues will make a measurement of the distribution of neutrons within the lead nucleus, adding a key piece of data to aid the description of heavy nuclei. This experiment, called PREX, will be the most precise measurement ever made in electron-nuclear scattering, measuring an asymmetry to about one part in 50 million.

Paschke received a Department of Energy Outstanding Junior Investigator grant from DOE's Office of Nuclear Physics in 2007. The grant is helping to further reduce the Jefferson Lab accelerator's electron beam asymmetries, which will improve the stability of the beam as it is manipulated for precision experiments. Paschke and his colleagues have already contributed greatly to electron beam asymmetries reduction for the HAPPEx series of experiments.

The work will make possible the high-precision measurement of the lead-208 nucleus. In addition, it will also help scientists further elucidate the properties of protons and neutrons. In three experiments – PREX, HAPPEx-III and Q-weak – physicists will explore how protons and neutrons respond to the fourth force of nature: the weak force..

During that time (2004), we lived in Williamsburg and had our son, Eric. In 2006, I was hired as an assistant professor at the University of Virginia. Our second child, Carsten, was born in October of that year, so it was a busy time for us with selling our house here, buying a new house there, and getting ready for the baby.

That also coincided with when I was doing my application for the DOE Outstanding Junior Investigator Award. Carsten was born a few weeks early and had a medical problem that meant he had to be transferred from Williamsburg to Norfolk General.  Although he wasn't in any immediate danger, it was certainly stressful for us. I finished writing the grant proposal at the hospital and got it in just under the wire. I certainly learned a lesson about pushing deadlines with a baby on the way.

Receiving this award in my first year at UVa was a huge boost for me. Since there is no "umbrella" grant and we are all funded by our own grants, this really let me get on with my program much more quickly. I was able to recruit a student to start research right away and to get on with assembling a research lab at the university to support Jefferson Lab research. As a junior faculty member, this sort of award helps make a positive first impression among my colleagues, and it certainly feels good to receive such a competitive award.

Although my initial and continuing attraction to physics was born of that "Gee whiz!" factor, like all physicists who have foregone the big bucks of industry for an academic career, I believe in the value of the work. I think that subatomic physics isn't just an expression of humanity's natural curiosity and fascination with shiny things, it is important in an enduring sense. Fundamental science contributes to the greater progress of humanity, and I like to think that what I do at Jefferson Lab contributes to that.

As told to Judi Tull

Feature Writer