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Far from Durham, A Physicist Explores the Frontier

Duke graduate student spends year at Europe's CERN pursuing the Higgs boson

Mia.jpg
Duke physics graduate student Mia Liu works on her computer. Credit: Alejandro Cortese.

It's a chilly morning along the border between France and Switzerland, and Miaoyuan Liu, a fourth-year Duke graduate student in physics, is getting ready for a long day of meetings and data analysis.

She grabs coffee from one of the many espresso stations at CERN, the world's largest particle physics laboratory, where she's been working since June. She has a meeting at 10:30 a.m., and will work on her computer until about 2 or 3 p.m. Then she'll video-chat with her advisor back in Durham, Duke physicist Al Goshaw.

Buried about a football field beneath Liu's feet is the Large Hadron Collider, or LHC, which slams sub-atomic particles together at nearly the speed of light. She and other Duke researchers have been analyzing the resulting collisions, seeking insights into how the universe works.

They've been looking especially for hints of a Higgs boson, which other particles "eat" to gain mass and make up the matter around us.

Liu is five months into a year-long stay at the facility, an immersive experience resembling that of an anthropology student engrossed in the culture of an indigenous tribe or a young biologist dispatched into an African forest to study chimpanzees.

"A hallmark of graduate education at Duke is the ability for students to develop not only breadth but depth in their chosen field of study," says Paula McClain, Duke's dean of graduate education. Liu's work at the LHC, McClain says, will help her develop that depth and accelerate her career.

Liu, 24, has been to CERN before, but only for a month or two at a time. She was born and grew up in China and attended Shandong University, five hours south of Beijing. There, she became interested in particle physics and in finding out, at a fundamental level, what makes up the world around her. She came to Duke in 2009 and began working with Goshaw -- first in Durham and later at CERN.

Now Liu is back at the lab for a year-long stay, which began with a bang. On July 4, she and other Duke students and researchers, along with about 200 other physicists, began lining up at 5 a.m. outside CERN's locked auditorium. Instead of trying to score a new iPhone 5 or tickets to a Duke-UNC game in Cameron Indoor Stadium, they sought seats to the greatest particle physics show in decades.

The wait was worth it. Liu and the others who entered the auditorium, along with millions watching around the world, witnessed the first firm indications that physicists had found a Higgs boson.

"Our work is about putting all of our effort toward discovering unknown things," she says, remembering the excitement of that moment at a job still new to her. "I was very curious about what exactly would be announced, evidence or discovery, since there were rumors on the street before the real announcement."

 Ashley Yeager, Duke.
Scientists at CERN meet in the cafeteria and discuss their work over lunch. Credit: Ashley Yeager, Duke.

At the event, two teams of researchers said they had found a particle that looked a lot like physicists' predictions of the Higgs boson. "But the properties of the particle still need to be studied carefully," Liu says. "It's like we see someone from far away now, and it looks like someone we are looking for, but we need to look closer to see who it is."

The announcement provided a dazzling start to Liu's time at CERN. Like almost all Duke graduate students in physics and other disciplines, however, her work in the laboratory has been filled more with hard work than with scientific sparklers.

"CERN is an intense place to work. It's not for everyone," says Duke research scientist Andrea Bocci, who is based at the particle accelerator full-time. For him, a typical day can last from 9 a.m. to 9 or 10 p.m., depending on how many meetings he has to attend to ensure that more than 3,000 people are collaborating effectively to use the equipment he helps oversee.

Bocci is the point person for part of the ATLAS detector, one of two machines scientists at CERN are using to hunt for evidence of Higgs bosons, and one of seven to investigate the fundamentals of particle physics. A team from Duke built one of the ATLAS instruments, the TRT, which consists of more than 370,000 "straws" that track charged particles and identify high-energy electrons after protons collide within the LHC. Liu, along with about 1,000 other graduate students, uses data from the TRT and other ATLAS components to look for new particles.

Working at CERN "really gives you a realistic look at what it means to be a scientist," Liu says. Though the days can seem long, with years passing between big announcements, her  experience has reinforced her decision to become a high-energy physicist and to spend a year so far from Durham.

While at CERN, she's tried to maintain a normal personal life. She's living in the French town of Saint-Genis-Pouilly, which is about two miles northwest of CERN and houses many graduate students, post-docs and other researchers from the lab. She also bought a second-hand BMW to commute to work, visit Geneva with friends and explore other parts of Europe.

In fact, Liu says her time at CERN has made her realize that, after finishing her year there and then another year or two writing her dissertation, she would like to come back to the lab and work as a post-doc. Then, after a few more years, she hopes to be ready to pursue a faculty position at a university. 

But for now, she's excited to be surrounded every day by some of the world's greatest physicists, working at her discipline's most celebrated facility and gaining experience and contacts. "I understand how competitive the field is and that you need to be very lucky and extremely good" to succeed in it, she says. Her time at CERN has provided an "opportunity to talk to experts and colleagues in person" and to "really create a network" to help build up her career.

On this chilly morning, there's still more data to analyze before she talks with Goshaw in the afternoon, and she also needs to start preparing for the many presentations and hallway conversations she expects to have with the Higgs physics group and others. After taking one final sip of coffee, she busses her mug and heads across the street, back to her office and to another day on the scientific frontier.