CU News
News from the University of Colorado in Boulder.
CU-BOULDER PART OF INTERNATIONAL TEAM TO DISCOVER NEUTRINOS CAN CHANGE ‘FLAVORS’
Jun 15th
An international research team led by Japan and including the University of Colorado Boulder may have taken a significant step in discovering why matter trumped antimatter at the time of the Big Bang, helping to create virtually all of the galaxies and stars in the universe.
The experiment, known as the Tokai to Kamioka experiment, or T2K, included shooting a beam of neutrinos underground from the Japan Proton Accelerator Research Complex, or J-PARC, on the country’s east coast to a detector near Japan’s west coast, a distance of about 185 miles. Elementary particles that are fundamental building blocks of nature, neutrinos generally travel at the speed of light and can pass through ordinary matter, like Earth’s crust, with ease. Neutrinos come in three types: muon, electron and tau.
The T2K team discovered that muon neutrinos can spontaneously change their “flavor” to electron neutrinos, a finding that may help explain why the universe is made up mostly of matter rather than antimatter, said CU-Boulder Assistant Professor Alysia Marino of the physics department, who is part of a university contingent that participated in the experiment. Scientists had previously measured the change of muon neutrinos to tau neutrinos and electron neutrinos to muon neutrinos or tau neutrinos, she said.
The shift of muon neutrinos to electron neutrinos detected in the new experiment is a new type of neutron oscillation that opens the way for new studies of a matter-antimatter symmetry called charge-parity, or CP violation, said Marino. “This CP violation phenomenon has not yet been observed in a neutrino, but may be the reason that our universe today is made up mostly of matter and not antimatter,” she said.
Scientists believe matter and antimatter were present in nearly equal proportions at the onset of the Big Bang. Since matter and antimatter particles cancel each other out, it has been proposed that there must have been CP violation in the early universe that produced slightly more matter than antimatter, which accounts for all the stars, galaxies, planets and life present today.
The T2K project is a collaboration of roughly 500 scientists from 12 nations. Other participating U.S. institutions include Boston University, Brookhaven National Laboratory, the University of California-Irvine, Colorado State University, Duke University, Louisiana State University, Stony Brook University, the University of Pittsburgh, the University of Rochester and the University of Washington. The United States contingent is funded by the U.S. Department of Energy.
The CU-Boulder group includes Marino, physics Associate Professor Eric D. Zimmerman, postdoctoral researchers Stephen Coleman and Robert Johnson, graduate students Andrew Missert and Tianlu Yuan, and former undergraduates Christopher Vanek, Bryan Kaufman, Eric Hansen, Zhon Butcher and Joshua Spitz.
The CU-Boulder team designed and built one of three magnetic horns used to generate neutrino beams. The horns are large aluminum conductors that use very high electrical currents to produce a magnetic field. The magnetic field focuses on short-lived neutrino-producing particles called pions and kaons, enhancing the intensity of the neutrino beam, said Zimmerman.
The CU-Boulder researchers also developed a device to monitor the position of the proton beam that creates the neutrinos. In addition, they contributed to the installation and operation of a T2K detector at the J-PARC site 60 miles northeast of Tokyo that measures the neutrinos right after they are produced, Marino said.
Zimmerman said more data will be required to confirm the new results. The J-PARC accelerator is being repaired following damage from the earthquake that hit Japan on March 11. The accelerator and experiment are expected to be operational again by the end of the year, said Zimmerman.
MAJORITY OF CU-BOULDER STUDENTS REPORT POSITIVE CAMPUS EXPERIENCE, ACCORDING TO SOCIAL CLIMATE SURVEY
Jun 1st
The survey, done in fall 2010, was the latest edition of CU-Boulder’s Social Climate Survey, conducted about every four years since 1994 by the university’s Office of Planning, Budget and Analysis, or PBA. The online survey was sent to 29,926 degree-seeking undergraduate and graduate students, and completed by 7,777, or 26 percent.
The favorable view of CU-Boulder’s social climate was generally shared by all subgroups studied — men and women, undergraduate and graduate students, students in all of the university’s schools and colleges, politically liberal and conservative students, students in fraternities and sororities, students who are the first in their family to attend college, gay and straight students, students from all socioeconomic backgrounds, students of different races and ethnicities, students with physical or psychological disabilities, nontraditional-age students, students who entered as freshmen and transfers, international students, students affiliated with the military, and students with different religious affiliations, including Catholics, other Christians, Jews, Muslims, Buddhists and nonbelievers. Membership in these self-identified subgroups was determined using survey responses provided by the students.
Overall, students described the campus as friendly and welcoming, with 80 percent of both undergraduate and graduate students reporting feeling welcome and accepted either often or very often. Eighty-eight percent said they feel comfortable in their classes, and 80 percent reported feeling intellectually stimulated. Large majorities described CU-Boulder as “accepting of diverse perspectives” in the classroom, 81 percent, and outside the classroom, 63 percent.
On a broad measure of feeling welcome and comfortable on campus and in the Boulder community, students who self-identified in diverse subgroups generally reported a positive experience — averaging about 4 on the 5-point scale. Although the positive assessment of the campus’s social climate was shared across all subgroups, two subgroups of at least 100 respondents did rate it slightly lower — around 3.5 — African-American students and students who characterized themselves as having a psychological or psychiatric disability such as depression or post-traumatic stress disorder. Their ratings were, however, still above the scale midpoint of 3.0. There was also a tendency for slightly less positive evaluations of the campus social climate by GLBT students, nontraditional-age students, students of lower socioeconomic status, very liberal students, very conservative students, students not affiliated with a fraternity or sorority, transfer students, and students affiliated with the Buddhist and Muslim faiths. Their ratings were, nevertheless, well above the neutral point on the scale.
Comprising 149 scaled questions, plus another six open-ended questions, the survey collected a massive amount of information — over a million responses to the ratings, and nearly 23,000 written comments, amounting to half a million words. The thousands of student comments include praise for particular classes that addressed diversity issues, suggestions to increase enrollment of international students and to make tuition more affordable for low-income students, reports of uncomfortable situations involving derogatory comments about women or gays or people of color, descriptions of personal experiences with religious or political prejudice, and accounts of situations that led to better understanding between people of different backgrounds. One student wrote, “Thanks for continuing to educate people on these issues, I feel like a much bigger and better person since I came to CU.”
Differences in survey results across 2001, 2006 and 2010 indicate an overall trend of small but consistent and wide-ranging improvements in the social climate on the CU-Boulder campus. For example, students’ level of comfort taking part in campus social life was higher in 2010, as were the average levels of feeling welcome, accepted, supported and intellectually stimulated at CU-Boulder. In all three surveys, African-American undergraduate students perceived the climate at CU-Boulder somewhat less favorably than did undergraduates of other races/ethnicities. Compared with 2001 and 2006, however, African-American undergraduates in 2010 reported feeling more welcome on the Boulder campus and more comfortable participating in campus social life and life on the Hill. Other students also reported feeling more welcome and comfortable in 2010.
A campus advisory board representing a wide range of campus units helped guide the survey and data analysis, including the assistant vice chancellor for diversity, equity and community engagement, the associate vice chancellor for undergraduate education, faculty, and representatives from student government, Disability Services, the GLBT Resource Center, Religious Campus Organizations, Wardenburg Health Center, the Office of Orientation, the Center for Multicultural Affairs and the Women’s Resource Center.
The survey’s findings are used primarily to evaluate, revise and develop programs and policies that promote student success by helping all students feel like valued members of the university community. PBA and members of the survey’s advisory board have been working together to distribute the results and encourage their use throughout the university community.
“For several years, the Office of Diversity, Equity and Community Engagement has worked with several campus community committees to assess and maintain the social climate for all students, especially as it impacts learning in and outside the classroom, as well as staff and faculty,” said Alphonse Keasley, assistant vice chancellor for diversity and equity. “The results of the latest survey will be most instructive in the ways that various Chancellor Advisory Committees can continue to recommend diversity and inclusion needs to ODECE and senior level administrators that are central to the campus’s mission and purpose.”
The results will also be used by academic affairs. “The Office of Undergraduate Education will be using specific results of this campus climate survey to fine tune or modify specific programs which have a significant focus on improving the welcoming climate we want for our students,” said Michael Grant, associate vice chancellor for undergraduate education. “For example, our McNeil, Daniels, Ethnic Living and Learning and Academic Excellence programs, among others, all work with students who may find understanding and fitting into a research university environment a particular challenge for it is often a really new and different cultural environment. This is also the case for many international students.”