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Seeking new physics in "virtual footprints"
Wackeroth uses CAREER grant to look for indirect evidence of new particles
By ELLEN GOLDBAUM
Contributing Editor
Like a detective tailing a frustratingly elusive perpetrator, UB scientist Doreen Wackeroth doesn't have much to go on when she searches for clues to the most basic questions in physics.
WACKEROTH
While other physicists seek more direct evidence of new particles, Wackeroth focuses on indirect evidence, the so-called virtual effects left by new particles during experiments conducted in extremely powerful high-energy particle accelerators.
"These particles can leave virtual footprints, as they pop in and out of existence so quickly that we are not able to directly detect them," says Wackeroth, assistant professor of physics in the College of Arts and Sciences. "Nevertheless, these virtual effects, or radiative corrections as they are called, have a measurable effect on the properties of all particles."
Wackeroth uses theoretical Monte Carlo simulations to bridge the gap from the conceptual world of mathematical physics to the actual detector signals observed in experiments in high-energy particle accelerators.
These accelerators generate tremendously powerful collisions between subatomic particles, creating tracks or footprints of sometimes even smaller and more fleeting particles, providing physicists with new clues as to their nature and behavior.
The most powerful new high-energy particle accelerator, an order of magnitude higher than anything currently available, is the CERN Large Hadron Collider (LHC), due to come online next year in Geneva, Switzerland.
To conduct her work at the LHC, Wackeroth recently received a prestigious five-year, $622,867 Faculty Early CAREER Development Award from the National Science Foundation (NSF). Such awards support the early career-development activities of teacher-scholars "who are most likely to become the academic leaders of the 21st century," according to the NSF.
The LHC will provide Wackeroth and other high-energy physicists with their best chance yet to answer some of the most basic questions in science, such as: What are the very smallest building blocks of matter and how do they shape the physical world?
According to the prevailing model of physics, the Standard Model, the answer to one of these questions should lie in the detection of the Higgs-boson particle, long predicted, but never seen.
"Since the Higgs particle is thought to be responsible for the masses of all particles, these efforts ultimately aim at solving one of the great mysteries of particle physics: Why do particles have mass?" Wackeroth explained.
Her research involves providing extremely precise predictions for how the Higgs-boson particle should behave and interact with the top quark, the heaviest known elementary particle.
"Since in particle physics, virtual effects are usually quite small, we need precise measurements and equally precise calculations in order for our experiments to be sensitive to them," she explained.
"If we want to precisely pin down the properties of particles, we need to take into account these virtual effects when making predictions that can then be compared with experimental results," she said.
According to Wackeroth, the detection of the Higgs-boson particle—or the failure to detect it—will serve to verify or negate one of the most fundamental assumptions of the Standard Model.
"If no Higgs-boson particle can be detected, then this part of the Standard Model is not correct, and if it's not right, then we have the possibility that there are signals of other types of physics, of new physics," she said. "In my research, I will keep testing the Standard Model against results from high-energy experiments to determine whether its predictions still agree with what we are seeing."
Wackeroth noted that physicists have been exploring the possibilities of what might determine the nature of mass in the event that the Standard Model turns out not to be the complete story.
"The Standard Model is pretty complicated," she said. "On the other hand, physicists believe that to find the fundamental law of nature and everything in the physical world, there should be one simple aesthetic, one basic principle that would explain all phenomena, a grand unified theory, a theory of everything."
She said that high-energy physicists expect the research that will be done at the LHC will provide guidance toward such an elegant, simplified theory of the physical world.
As part of her NSF award, Wackeroth is conducting a "Physics and Arts Summer Institute" at UB this summer for high school students, who will build an exhibit designed to convey the excitement of physics to the general public.