Parallel universe? In what may seem like the stuff of science fiction, recent experiments at Brookhaven National Laboratory have strengthened the case for supersymmetry, a theory proposed by physicists positing the possible existence of a “shadow universe.” Although none has thus far been observed, the theory predicts that every known particle in our universe has a counterpart.
Lee Roberts, a CAS physics professor, is Brookhaven’s spokesman for the Muon G-2 Collaboration, which recently reported a new measurement of the rate at which negatively charged muons (elementary particles similar to electrons) spin as they move through a magnetic field. The new data largely accord with earlier measurements using positively charged muons. Both sets of measurements indicate that the muon spins slightly faster than the rate predicted by the Standard Model, the model nuclear physicists use to describe the forces and particles of the universe. The results give a tantalizing hint that effects of physics beyond the Standard Model may have been seen.
Boston University has had a leadership role in this project for many years, with Physics Professor James Miller and Associate Professor Robert Carey leading significant portions of the effort. Graduate students Jonathan Paley (GRS’04) and Xiaobo Huang (GRS’04) provided two of the five analyses that went into this new result.
Physicists have known for some time that the Standard Model is incomplete, and supersymmetry -- which predicts the existence of yet-to-be-discovered companion particles for all presently known subatomic particles -- is a leading contender for extending the model.
New York Times science writer James Glanz compared the G-2 experiments to high school science experiments studying “ . . . Brownian motion, which long ago provided evidence for the atomic structure of ordinary matter. When seen through a microscope, dust motes in liquids jitter about, because they are repeatedly struck by otherwise invisible atoms and molecules. Physicists know that seemingly empty space is populated by a kind of fizz of particles that flit into and out of existence. The muons . . . gyrate like tops in a powerful magnetic field in a vacuum chamber. Like the dust motes, the muons encounter the other particles and gyrate differently as a result.”
Muon studies require huge and expensive equipment such as a synchrotron to produce the muons, and the world’s largest superconducting magnet to store them while they spin around. They need to be run for extended periods to accumulate sufficient data to reach the precision of half a part in a million.
With the end of funds for further work at Brookhaven, Roberts and his colleagues are actively seeking new funds to continue their work, since the results, while provocative, are not yet conclusive.
These findings have been submitted to Physical Review Letters.
Working it out. According to recent research at Sargent College’s Center for Psychiatric Rehabilitation, people with serious mental illness not only have the capacity to return to work, but with appropriate support can be very successful, even at demanding technical, professional, and administrative positions. “One of the old myths was that people with serious mental illness could only do low-level jobs -- the so-called F jobs: flowers, filing, food. We have done studies that have documented the capacity of the mentally ill to be successfully employed in many fields,” says Zlatka Russinova, a SAR research assistant professor and the study’s lead author.
The five-year study followed 696 individuals with serious psychiatric conditions, 80 percent of whom had had at least one psychiatric hospitalization and 95 percent of whom were taking psychotropic medications. The researchers found that 74 percent of the participants had been continuously employed for a two-year period, 17 percent were employed for 18 out of 24 months, and 9 percent were employed for 12 to 18 months. They found that 74 percent of participants worked 35 or more hours a week, with 53 percent in professional or technical jobs and 24 percent in managerial or administrative positions.
While psychiatric diagnosis was not associated with the participants’ ability to sustain employment, it was associated with occupational status, the number of hours worked per week, and salary level. Participants with a diagnosis of bipolar disorder tended to have higher occupational status, work longer hours, and earn a larger salary than other diagnostic groups.
“These people haven’t been cured,” Russinova says. “They rely on the mental health system to maintain their working capacity.” Study participants reported that consistent use of medication was the factor most crucial to their success, followed by support from a spouse or significant other and the support of a therapist. Russinova stresses that education is an important factor: “People do better if they acquire a better education prior to getting sick, or acquire schooling afterwards through vocational rehabilitation programs.”
This work was presented at the 2002 National Conference on Innovations in Recovery and Rehabilitation. Findings on a subset of the group with a diagnosis of schizophrenia were presented at the 2003 annual meeting of the American Psychiatric Association.
Briefs" is written by Joan Schwartz in the Office of the Provost. To read
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