Research notes

Pentaquarks: A new form of matter

Evidence for the "pentaquark" has been reported recently by experiments in Japan, Russia and the United States. The new particle's properties—such as mass, decay time and decay mode—fit to theoretical predictions of a five-quark system, known as a pentaquark. Such a particle would constitute a new form of matter.

Gamma rays hitting the nuclei of heavy hydrogen atoms may cause pentaquarks and other sub-atomic particles. A pentaquark is composed of five quarks. This new particle constitutes a new form of matter.(Illustration courtesy Physics Department)

"It is important that the signature for this new particle has been found at various laboratories around the world, but in many different reactions. This enhances the credibility of the existence of this new particle," says Professor Wolfgang Lorenzon, who participated on a U-M team that confirmed the existence of the new particle in the debris of high-energy collisions, together with a team led by Professor Moskov Amarian from the German Zeuthen research group.

The U-M physics team, consisting of Lorenzon and research fellow Avetik Airapetian, is part of HERMES, a multinational experimental collaboration working at the HERA particle accelerator at the DESY laboratory in Hamburg, Germany.

By sifting through millions of interactions of high-energy positrons with deuterium nuclei, the scientists isolated 30 events that cannot be explained in terms of the standard known particles. The combination of particles detected in these events indicates the decay of a new particle with a mass of 1.6 times that of a proton.

The observed properties of this particle are remarkably consistent with those predicted in 1997 by a group of Russian scientists who said it would have five quarks bound together. Up until now only combinations of two or three quarks have been observed in nature. On the other hand, physicists have been searching for many years for more exotic combinations, which also are permitted by the basic theory of quark interactions known as Quantum Chromo Dynamics, or QCD. With the new data from HERMES, which have been measured at much higher beam energy, the existence of this new form of matter now seems well established.
--Carol Rabuck, Department of Physics

Treatment, not only incarceration, needed for male adolescent sex offenders

Sexually abused youths who are serving time for their crimes are more likely to repeat assaults done to them unless they get psychological counseling during incarceration, according to a U-M professor.

In David Burton's study, "Male Adolescents: Sexual victimization and subsequent sexual abuse," he collected data from nearly 180 adolescent sexual abusers in four Michigan detention centers. His research supports the idea that providing treatment for youths is one answer to prevent future assaults. The problem, he says, is that jails, prisons and detention centers don't have the funding to offer treatment, partly because many counties and states have trimmed their budgets.

Based on a national survey in 2000 by Burton, who teaches in the School of Social Work, and Joanne Smith-Darden, a student in the school's joint doctoral program, the study shows that treatment for adolescents takes about 1.5 years and usually is cognitive-behavioral in nature: it works toward changing thoughts, feelings, behaviors and childhood events that cause sexual aggression.

The study found that, indeed, many youths repeated what was done to them. For example, a youth that was sexually abused by a male was six times more likely to sexually abuse a male than a youth who was not sexually abused by a male. A youth who was sexually abused with direct force was nearly four times more likely to sexually abuse using direct force than a youth who was not sexually abused in this manner.

Burton's research appears in the August issue of Child and Adolescent Social Work Journal. The research can be found at http://www.kluweronline.com/issn/0738-0151/contents.
--Jared Wadley, News Service

Virtuous firms perform better

Companies perceived as trusting, compassionate and high in integrity perform better and have higher profits than less virtuous firms—even when downsizing, according to a study from the Business School.

"We found that a positive association exists between the extent to which organizations foster and facilitate virtuousness and the performance of organizations," says Kim Cameron, professor of organizational behavior and human resource management at the Business School. "Specifically, virtuous organizations perform significantly better on indicators such as profitability, customer satisfaction, quality and so on."

In a study appearing in an upcoming issue of the journal American Behavioral Scientist, Cameron and colleagues David Bright of Case Western Reserve University's Weatherhead School of Management, and Arran Caza of the U-M Business School developed a statistical model to measure organizational attributes and behaviors of more than 800 employees at 18 companies based mostly in the Midwest.

The researchers found that higher levels of perceived organizational virtuousness—forgiveness, trust, integrity, optimism and compassion—are related positively to higher levels of real and perceived organizational performance when performance is compared with the industry average, best competitor, past improvement and stated goals. Cameron and colleagues say virtuousness impacts five measures of organizational performance: innovation, customer retention, turnover, quality and profitability.
--Bernie DeGroat, News Service

Most women can skip Pap smears after hysterectomy

Most women who have undergone a hysterectomy for non-cancerous diseases can forgo annual Pap smear exams, according to research by U-M Health System physicians.

The study, published in the July issue of the Journal of Lower Genital Tract Disease, found that even in the best conditions, women add only three weeks to their lives by having regular screenings. The cost of these screenings per year of life saved can cost up to $12 million for more aggressive screening plans. It is the first study to look at the value of Pap smear screenings for women who have had a hysterectomy.

"Everyone thinks more prevention is better. What we found is that just because you have a test available doesn't mean you should use it. Some tests are not really going to lead to any benefit," says lead study author Dr. Michael Fetters, assistant professor of family medicine at the Medical School. The authors say that even if the Pap smear isn't necessary for women with total hysterectomies, an annual trip to the doctor still is important.

The study co-author was Dr. Richard Lieberman, clinical assistant professor in pathology and obstetrics and gynecology at the Medical School. Authors also included Paul Abrahamse, Consortium for Health Outcomes, Innovation and Cost Effectiveness Studies at U-M; Rupal Sanghvi, International Planned Parenthood Federation, Western Hemisphere Region; and Seema Sonnad, Department of Surgery at the University of Pennsylvania.

The study was funded by Blue Cross Blue Shield of Michigan Foundation, the American Academy of Family Physicians Foundation, and the Robert Wood Johnson Foundation Generalist Faculty Scholars Program.
--Nicole Fawcett, UMHS Public Relations

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