Jennifer Rittenhouse West

Jennifer Rittenhouse West loves physics in the same way that some kids love LEGO sets. For fun, she looks through paper archives and reads her favorite physics authors. She has to remember not to think too deeply about physics when she’s biking down a busy street. So she was thrilled to join Berkeley Lab in August, 2020, to work on research related to the Electron-Ion Collider and beyond.

Can you tell us about your work on the Electron-Ion Collider and why you're interested in it?

I’m interested in fundamental particles and forces—particles that appear to be indivisible, particles like quarks and gluons—and their effects within protons, neutrons, and nuclei. The Electron-Ion Collider (EIC) is an ambitious project to be built over the next 10-plus years that will probe the behavior of these particles and forces at very small scales.

My collaborators and I are interested in quantities like mass and spin; using simulated EIC collision debris to understand how the quarks, gluons, and antiquarks spin around inside the neutron, which is fascinating. You have to be on your toes working with neutron spin, because neutrons have a half life of about 15 minutes. You have to stabilize the neutrons by putting them together with protons. We intend to use helium-3 as a target, which is two protons and one neutron. But this means we have to make sure that the electron beam hits just the neutron and not the protons, and this is tricky. Our recent EIC paper dealt with how to do it. The trick, which is called “double spectator tagging,” is to track the protons to see that they didn’t participate in the collision. It’s very cool physics and only the EIC can do it.

What are you most excited about at Berkeley Lab?

I’m incredibly happy to be at such a storied institution. I was so excited to join my colleagues here. I recently met with two senior scientists in experimental nuclear physics and we had great brainstorming sessions. There is a lot going on at the Lab in nuclear theory and experimentation, in particle theory, and in the growing field of quantum information science (not to mention clean energy, environmental science, biosciences!). There’s so much cutting-edge science being done here. It is like playing tennis with champions; your game improves exponentially.

One very fun aspect of being at the Lab is co-organizing a seminar series on hadrons and ions. Hadrons are bundles of two or more quarks, and ions are charged atoms from which we’ve pulled off one or more electrons. There is so much brilliant work being done in these fields globally, especially with the advancement of the EIC project this year, and being a co-organizer means I can invite any of the authors of these works to give a seminar at the Lab. We’ve had fantastic virtual talks this fall.

Lab Director Mike Witherell was one of your professors when you were an undergrad at UCSB, many years ago. What was he like as a professor?

He was awesome. It was an introductory class on elementary particle physics. Mike was passionate about particle physics and knew his subject inside out. And his door was always open. I remember asking him for a letter of recommendation after taking his class. He agreed to do this and asked me to pass by his office. I was very nervous when I went to meet with him; we were going to discuss my undergraduate research project (with his amazing colleague Prof. Jim Hartle) on generalized quantum mechanics. He sensed I was a bundle of nerves and was quick to reassure me that he was happy to write a letter for me, he just wanted to talk about physics! And we had a great conversation.

I can see that Mike is the same way at the Lab. I came on board in August 2020, when we were about six months into the pandemic. He analyzed the COVID landscape and regularly communicated with the entire Lab. He showed that he cared about everyone and that we were all in this together. Even though I came to the Lab during the pandemic, Mike's messages about the importance of everyone supporting each other and the spirit of IDEA helped keep our community together. I couldn’t be more pleased that my path has crossed his again, especially now.