Correction: The story originally said Richman received his Ph.D. in 1988. He received it in 1985. Also, the Silicon Vertex Tracker was not built almost entirely at UCSB. The Nexus regrets these errors.
As a kid, Jeffrey Richman spent a lot of time around both particle accelerators and dockyards. Luckily for UCSB, he was prone to seasickness and pursued his love of physics, which earned him the 2008 Fellow award for the American Association for the Advancement of Science.
Richman, whose father worked on the Manhattan Project developing the first atomic bomb, has taught physics at UCSB since 1988 after receiving his Ph.D. at the California Institute of Technology in 1985. The professor works to unlock the secrets of the most elusive particles known to science – including quarks, which are smaller than atoms – using high-energy particle accelerators.
The scientist received the Fellow award for his role as physics coordinator in 2003-2004 on the BaBar experiment at Stanford Linear Accelerator Center, for which he directed a staff of 600. If the name sounds familiar, it is because the experiment was named after the popular French fictional character, Babar the elephant, who is also the experiment’s official symbol.
Unlike its childish namesake, the ongoing BaBar experiment continues to delve into such weighty questions as how matter in the universe was created.
Although Richman is no longer the physics coordinator, he is still involved in the physics measurements. Currently, Richman works with muons – elementary particles with a negative electric charge – at the European Organization for Nuclear Research in Geneva, Switzerland.
BaBar: CIA Secret?
Eleven countries collaborate on BaBar experiments. Because the accelerator is so large and is located in a secluded location near Palo Alto, many people think this construction is a secret CIA installation, Richman said.
He also said the project studies matter and antimatter, including quarks, which are particles smaller than atoms. In fact, it takes three quarks to make the positive charge of a proton, and scientists believe that they cannot further break quarks into smaller constituent parts. BaBar specifically studies Bmeson and anti Bmesons – which are particles composed of quarks – also known as B and B-bar, hence the name of the project.
For every particle of matter, a particle of antimatter exists, which has the same mass but opposite charge, Richman said. In this case, Bmesons make up matter and anti Bmesons make up anti-matter. When matter and antimatter come into contact, they annihilate each other.
The two-mile-long accelerator experiments with these clashes by firing electrons at positrons in the Silicon Vertex Tracker, a device partially built at UCSB. The SVT records precise measurements of particles – which collide at almost the speed of light – and the place where they decay and transform, Richman said.
The energy from the collisions transforms the particles into different quarks, Richman said. However, he said the type of quark created depends on the laws of nature.
“Our goal is to figure out the rules for how that works,” Richman said.
The BaBar experiment has a detector that records an electronic picture each time the electrons and positrons collide, Richman said. Since not every transformation is useful in revealing new knowledge of how the process works, approximately 500 million electronic pictures were taken to study why these quarks transform, he said. Six kinds of quarks exist: u(up), d(down), c(charm), s(strange), t(top) and b(bottom) which are coupled together in doublets and known as generations. These six quarks make up a mathematical jigsaw puzzle, Richman said.
“When you start to try to understand their behavior you have to understand all of them and how they relate to each other,” he said.
The Beginning of the Universe
Although the early universe had similar ratios of matter to antimatter, today’s version does not have much antimatter, Richman said.
“It is widely believed nearly all matter and antimatter collided and we are the leftover matter,” he said.
According to Richman, in order to have different amounts of matter an antimatter, a condition known as a CP violation must exist. Although scientists know how quarks manage to create CP violations, not enough is known to explain why matter – like humans – exists, he said.
“If there were no CP violation in the universe, we’re pretty sure we wouldn’t exist because matter and antimatter cancel each other out or else the universe would be an incredibly dangerous place to be,” Richman said. “If you ran into the anti-you, you would be history.”
New Forms of Matter, New Dimensions?
Richman’s new enterprise is the Compact Muon Solenoid project at CERN, which is similar to BaBar, with the exception that it collides protons with other protons instead of electrons. Although this experiment was in preparation for many years, Richman only became involved two years ago. He works with several post-doctorates, graduate students and one undergraduate student to write software to analyze data that determines the presence of certain particles and measures their activity, he said.
The experiment has not yet begun, but the team already has high expectations. Richman said he expects CMS to produce the highest energy collisions ever achieved in accelerator experiments.
“There is some reasonable expectation that we will observe new physical phenomenon,” Richman said. “One [new observation] is the origin of mass, and it could be that a whole new set of particles will appear that are relatives of the matter we’re familiar with.”
A new form of matter may exist, known as super-symmetric particles, which is neither matter nor antimatter, Richman said.
“Some people think there’s a chance of discovering extra dimensions of space,” Richman said.
AAAS is an international nonprofit organization that publishes Science, the largest paid circulation of peer-reviewed general science. To become an AAAS Fellow, a scientist is nominated by steering groups of the Association’s 24 sections, three current AAAS Fellows or the Chief Executive Officer. This year, 471 members became Fellows, five of them from UCSB.