Neutrinos change flavors while crossing Japan: Findings shed light on why universe is made of matter instead of anti-matter

ScienceDaily (June 15, 2011) — By shooting a beam of neutrinos through a small slice of Earth under Japan, physicists say they've caught the particles changing their stripes in new ways. These observations may one day help explain why the universe is made of matter rather than anti-matter.

The T2K experiment has been using the Japan Proton Accelerator Research Complex, or J-PARC, located on the east coast, to shoot a beam of muon neutrinos 185 miles, or 295 kilometers, underground toward the Super-Kamiokande, or Super-K, detector in Kamioka, near Japan's west coast.

The goal of the experiment, which is part of a new generation of neutrino-tracking facilities, is to observe the particles changing "flavors" from muon neutrinos to electron neutrinos on this brief journey.

Neutrinos are elementary particles that come in three flavors -- muon, electron and tau. In past experiments, physicists have measured the change of muon neutrinos to tau neutrinos and electron neutrinos to muon neutrinos or tau neutrinos.

"But no one had seen muon neutrinos turn into electron neutrinos," said Chris Walter, a physicist at Duke who is part of the T2K collaboration, along with Duke physicist Kate Scholberg.

The T2K collaboration, a team of physicists from around the world, began observing the neutrinos for their transformations in January 2010. The group measured the neutrinos, determining their flavor near the accelerator and then again at Super-K. So far, scientists caught 88 neutrinos with their detector. Six of these likely began their lives as muon neutrinos and turned into electron neutrinos on their way to Super-K.

"As it stands, this result is extremely interesting, but we are just getting started," Walter said. He explained that the T2K team has taken a little less than two percent of the planned neutrino measurements, partly due to the East Japan earthquake that struck on March 11, 2011 and forced the shutdown of T2K.

The preliminary findings were submitted to Physical Review Letters and announced at a press conference June 15 in Japan.

"We could see as many electron neutrino candidates as we saw by chance, something, like one out of every 150 times," Walter said. "This is why the title of our paper includes the word 'indications' as opposed to observation or measurement."

If the "indications" become "measurements," these T2K results will be the first to measure a muon-electron neutrino change. Scientists want this measurement to study a fundamental parameter of physics called theta-13, which controls the muon-electron neutrino switch. Walter said there is more than one way to measure theta-13 and that several experiments are currently competing to be the first.

"It's good news that we have evidence of a relatively large theta-13, since there are even more interesting measurements that can be done if it is big enough," he said.

If theta-13 is large, it will allow scientists to measure the difference between oscillations of neutrinos and oscillation of anti-neutrinos. Walter explained that in the early universe, "something caused there to be slightly more matter than anti-matter. When the matter and anti-matter annihilated each other, only that little bit of matter was left over. That matter is everything we see around us today. But no one understands how this happened."

"The difference between neutrino and anti-neutrino properties that we might measure in future experiments might give clues to how the excess matter was generated," Walter said.

Of course that all depends on how quickly T2K can come back online after being shut down from the earthquake. Currently, the experiment is slated to re-start at the end of 2011.

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by Duke University.

Journal References:

The T2K Collaboration. Indication of Electron Neutrino Appearance from an Accelerator-produced O -axis Muon Neutrino Beam. Physical Review Letters, 2011; (submitted)The T2K Collaboration. The T2K Experiment. arXiv.org, 2011; [link]

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Neutrinos change flavors while crossing Japan: Findings shed light on why universe is made of matter instead of anti-matter

ScienceDaily (June 15, 2011) — By shooting a beam of neutrinos through a small slice of Earth under Japan, physicists say they've caught the particles changing their stripes in new ways. These observations may one day help explain why the universe is made of matter rather than anti-matter.

The T2K experiment has been using the Japan Proton Accelerator Research Complex, or J-PARC, located on the east coast, to shoot a beam of muon neutrinos 185 miles, or 295 kilometers, underground toward the Super-Kamiokande, or Super-K, detector in Kamioka, near Japan's west coast.

The goal of the experiment, which is part of a new generation of neutrino-tracking facilities, is to observe the particles changing "flavors" from muon neutrinos to electron neutrinos on this brief journey.

Neutrinos are elementary particles that come in three flavors -- muon, electron and tau. In past experiments, physicists have measured the change of muon neutrinos to tau neutrinos and electron neutrinos to muon neutrinos or tau neutrinos.

"But no one had seen muon neutrinos turn into electron neutrinos," said Chris Walter, a physicist at Duke who is part of the T2K collaboration, along with Duke physicist Kate Scholberg.

The T2K collaboration, a team of physicists from around the world, began observing the neutrinos for their transformations in January 2010. The group measured the neutrinos, determining their flavor near the accelerator and then again at Super-K. So far, scientists caught 88 neutrinos with their detector. Six of these likely began their lives as muon neutrinos and turned into electron neutrinos on their way to Super-K.

"As it stands, this result is extremely interesting, but we are just getting started," Walter said. He explained that the T2K team has taken a little less than two percent of the planned neutrino measurements, partly due to the East Japan earthquake that struck on March 11, 2011 and forced the shutdown of T2K.

The preliminary findings were submitted to Physical Review Letters and announced at a press conference June 15 in Japan.

"We could see as many electron neutrino candidates as we saw by chance, something, like one out of every 150 times," Walter said. "This is why the title of our paper includes the word 'indications' as opposed to observation or measurement."

If the "indications" become "measurements," these T2K results will be the first to measure a muon-electron neutrino change. Scientists want this measurement to study a fundamental parameter of physics called theta-13, which controls the muon-electron neutrino switch. Walter said there is more than one way to measure theta-13 and that several experiments are currently competing to be the first.

"It's good news that we have evidence of a relatively large theta-13, since there are even more interesting measurements that can be done if it is big enough," he said.

If theta-13 is large, it will allow scientists to measure the difference between oscillations of neutrinos and oscillation of anti-neutrinos. Walter explained that in the early universe, "something caused there to be slightly more matter than anti-matter. When the matter and anti-matter annihilated each other, only that little bit of matter was left over. That matter is everything we see around us today. But no one understands how this happened."

"The difference between neutrino and anti-neutrino properties that we might measure in future experiments might give clues to how the excess matter was generated," Walter said.

Of course that all depends on how quickly T2K can come back online after being shut down from the earthquake. Currently, the experiment is slated to re-start at the end of 2011.

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by Duke University.

Journal References:

The T2K Collaboration. Indication of Electron Neutrino Appearance from an Accelerator-produced O -axis Muon Neutrino Beam. Physical Review Letters, 2011; (submitted)The T2K Collaboration. The T2K Experiment. arXiv.org, 2011; [link]

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

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Novel geothermal technology packs a one-two punch against climate change

ScienceDaily (June 7, 2011) — Two University of Minnesota Department of Earth Sciences researchers have developed an innovative approach to tapping heat beneath Earth's surface. The method is expected to not only produce renewable electricity far more efficiently than conventional geothermal systems, but also help reduce atmospheric carbon dioxide (CO2) -- dealing a one-two punch against climate change.

The approach, termed CO2-plume geothermal system, or CPG, was developed by Earth sciences faculty member Martin Saar and graduate student Jimmy Randolph in the university's College of Science and Engineering. The research was published in the most recent issue of Geophysical Research Letters. The researchers have applied for a patent and plan to form a start-up company to commercialize the new technology.

Established methods for transforming Earth's heat into electricity involve extracting hot water from rock formations several hundred feet from Earth's surface at the few natural hot spots around the world, then using the hot water to turn power-producing turbines. The university's novel system was born in a flash of insight on a northern Minnesota road trip and jump-started with $600,000 in funding from the U of M Institute on the Environment's Initiative for Renewable Energy and the Environment (IREE). The CPG system uses high-pressure CO2 instead of water as the underground heat-carrying fluid.

CPG provides a number of advantages over other geothermal systems, Randolph said. First, CO2 travels more easily than water through porous rock, so it can extract heat more readily. As a result, CPG can be used in regions where conventional geothermal electricity production would not make sense from a technical or economic standpoint.

"This is probably viable in areas you couldn't even think about doing regular geothermal for electricity production," Randolph said. "In areas where you could, it's perhaps twice as efficient."

CPG also offers the benefit of preventing CO2 from reaching the atmosphere by sequestering it deep underground, where it cannot contribute to climate change. In addition, because pure CO2 is less likely than water to dissolve the material around it, CPG reduces the risk of a geothermal system not being able to operate for long times due to "short-circuiting" or plugging the flow of fluid through the hot rocks. Moreover, the technology could be used in parallel to boost fossil fuel production by pushing natural gas or oil from partially depleted reservoirs as CO2 is injected.

Saar and Randolph first hit on the idea behind CPG in the fall of 2008 while driving to northern Minnesota together to conduct unrelated field research. The two had been conducting research on geothermal energy capture and separately on geologic CO2 sequestration.

"We connected the dots and said, 'Wait a minute -- what are the consequences if you use geothermally heated CO2?'" recalled Saar. "We had a hunch in the car that there should be lots of advantages to doing that."

After batting the idea around a bit, the pair applied for and received a grant from the Initiative for Renewable Energy and the Environment, which disburses funds from Xcel Energy's Renewable Development Fund to help launch potentially transformative projects in emerging fields of energy and the environment. The IREE grant paid for preliminary computer modeling and allowed Saar and Randolph to bring on board energy policy, applied economics and mechanical engineering experts from the University of Minnesota as well as modeling experts from Lawrence Berkeley National Laboratory. It also helped leverage a $1.5 million grant from the U.S. Department of Energy to explore subsurface chemical interactions involved in the process.

"The IREE grant was really critical," Saar said. "This is the kind of project that requires a high-risk investment. I think it's fair to say that there's a good chance that it wouldn't have gone anywhere without IREE support in the early days."

Saar and Randolph have recently applied for additional DOE funding to move CPG forward to the pilot phase.

"Part of the beauty of this is that it combines a lot of ideas but the ideas are essentially technically proven, so we don't need a lot of new technology developed," Randolph said.

"It's combining proven technology in a new way," Saar said. "It's one of those things where you know how the individual components work. The question is, how will they perform together in this new way? The simulation results suggest it's going to be very favorable."

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by University of Minnesota.

Journal Reference:

Jimmy B. Randolph, Martin O. Saar. Combining geothermal energy capture with geologic carbon dioxide sequestration. Geophysical Research Letters, 2011; 38 (10) DOI: 10.1029/2011GL047265

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Phase change memory-based 'Moneta' system points to the future of computer storage

ScienceDaily (June 3, 2011) — A University of California, San Diego faculty-student team is about to demonstrate a first-of-its kind, phase-change memory solid state storage device that provides performance thousands of times faster than a conventional hard drive and up to seven times faster than current state-of-the-art solid-state drives (SSDs).

The device was developed in the Computer Science and Engineering department at the UC San Diego Jacobs School of Engineering and will be on exhibit June 7-8 at DAC 2011, the world's leading technical conference and trade show on electronic design automation, with the support of several industry partners, including Micron Technology, BEEcube and Xilinx. The storage system, called "Moneta," uses phase-change memory (PCM), an emerging data storage technology that stores data in the crystal structure of a metal alloy called a chalcogenide. PCM is faster and simpler to use than flash memory -- the technology that currently dominates the SSD market.

Moneta marks the latest advancement in solid state drives (SSDs). Unlike conventional hard disk drives, solid state storage drives have no moving parts. Today's SSDs use flash memory and can be found in a wide range of consumer electronics such as iPads and laptops. Although faster than hard disk, flash memory is still too slow to meet modern data storage and analysis demands, particularly in the area of high performance computing where the ability to sift through enormous volumes of data quickly is critical. Examples include storing and analyzing scientific data collected through environmental sensors, or even web searches through Google.

"As a society, we can gather all this data very, very quickly -- much faster than we can analyze it with conventional, disk-based storage systems," said Steven Swanson, professor of Computer Science and Engineering and director of the Non-Volatile Systems Lab (NVSL). "Phase-change memory-based solid state storage devices will allow us to sift through all of this data, make sense of it, and extract useful information much faster. It has the potential to be revolutionary."

PCM Memory Chips

To store data, the PCM memory chips switch the alloy between a crystalline and amorphous state based on the application of heat through an electrical current. To read the data, the chips use a smaller current to determine which state the chalcogenide is in.

Moneta uses Micron Technology's first-generation PCM chips and can read large sections of data at a maximum rate of 1.1 gigabytes per second and write data at up to 371 megabytes per second. For smaller accesses (e.g., 512 B), Moneta can read at 327 megabytes per second and write at 91 megabytes per second , or between two and seven times faster than a state-of-the-art, flash-based SSD. Moneta also provides lower latency for each operation and should reduce energy requirements for data-intensive applications.

A Glimpse at Computers of the Future

Swanson hopes to build the second generation of the Moneta storage device in the next six to nine months and says the technology could be ready for market in just a few years as the underlying phase-change memory technology improves. The development has also revealed a new technology challenge.

"We've found that you can build a much faster storage device, but in order to really make use of it, you have to change the software that manages it as well. Storage systems have evolved over the last 40 years to cater to disks, and disks are very, very slow," said Swanson. "Designing storage systems that can fully leverage technologies like PCM requires rethinking almost every aspect of how a computer system's software manages and accesses storage. Moneta gives us a window into the future of what computer storage systems are going to look like, and gives us the opportunity now to rethink how we design computer systems in response."

In addition to Swanson, the Moneta team includes Computer Science and Engineering Professor and Chair Rajesh Gupta, who is also associate director of UC San Diego's California Institute for Telecommunications and Information Technology. Student team members from the Department of Computer Science and Engineering include Ameen Akel, Adrian Caulfield, Todor Mollov, Arup De, and Joel Coburn.

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by University of California - San Diego, Jacobs School of Engineering.

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Effects of climate change in Arctic more extensive than expected, report finds

ScienceDaily (May 4, 2011) — A much reduced covering of snow, shorter winter season and thawing tundra: The effects of climate change in the Arctic are already here. And the changes are taking place significantly faster than previously thought. This is what emerges from a new research report on the Arctic, presented in Copenhagen this week. Margareta Johansson, from Lund University, is one of the researchers behind the report.

Together with Terry Callaghan, a researcher at the Royal Swedish Academy of Sciences, Margareta is the editor of the two chapters on snow and permafrost.

"The changes we see are dramatic. And they are not coincidental. The trends are unequivocal and deviate from the norm when compared with a longer term perspective," she says.

The Arctic is one of the parts of the globe that is warming up fastest today. Measurements of air temperature show that the most recent five-year period has been the warmest since 1880, when monitoring began. Other data, from tree rings among other things, show that the summer temperatures over the last decades have been the highest in 2000 years. As a consequence, the snow cover in May and June has decreased by close to 20 per cent. The winter season has also become almost two weeks shorter -- in just a few decades. In addition, the temperature in the permafrost has increased by between half a degree and two degrees.

"There is no indication that the permafrost will not continue to thaw," says Margareta Johansson.

Large quantities of carbon are stored in the permafrost.

"Our data shows that there is significantly more than previously thought. There is approximately double the amount of carbon in the permafrost as there is in the atmosphere today," says Margareta Johansson.

The carbon comes from organic material which was "deep frozen" in the ground during the last ice age. As long as the ground is frozen, the carbon remains stable. But as the permafrost thaws there is a risk that carbon dioxide and methane, a greenhouse gas more than 20 times more powerful than carbon dioxide, will be released, which could increase global warming.

"But it is also possible that the vegetation which will be able to grow when the ground thaws will absorb the carbon dioxide. We still know very little about this. With the knowledge we have today we cannot say for sure whether the thawing tundra will absorb or produce more greenhouse gases in the future," says Margareta Johansson.

Effects of this type, so-called feedback effects, are of major significance for how extensive global warming will be in the future. Margareta Johansson and her colleagues present nine different feedback effects in their report. One of the most important right now is the reduction of the Arctic's albedo. The decrease in the snow- and ice-covered surfaces means that less solar radiation is reflected back out into the atmosphere. It is absorbed instead, with temperatures rising as a result. Thus the Arctic has entered a stage where it is itself reinforcing climate change.

The future does not look brighter. Climate models show that temperatures will rise by a further 3 to 7 degrees. In Canada, the uppermost metres of permafrost will thaw on approximately one fifth of the surface currently covered by permafrost. The equivalent figure for Alaska is 57 per cent. The length of the winter season and the snow coverage in the Arctic will continue to decrease and the glaciers in the area will probably lose between 10 and 30 per cent of their total mass. All this within this century and with grave consequences for the ecosystems, existing infrastructure and human living conditions.

New estimates also show that by 2100, the sea level will have risen by between 0.9 and 1.6 metres, which is approximately twice the increase predicted by the UN's panel on climate change, IPCC, in its 2007 report. This is largely due to the rapid melting of the Arctic icecap. Between 2003 and 2008, the melting of the Arctic icecap accounted for 40 per cent of the global rise in sea level.

"It is clear that great changes are at hand. It is all happening in the Arctic right now. And what is happening there affects us all," says Margareta Johansson.

The report "Impacts of climate change on snow, water, ice and permafrost in the Arctic" has been compiled by close to 200 polar researchers. It is the most comprehensive synthesis of knowledge about the Arctic that has been presented in the last six years. The work was organised by the Arctic Council's working group for environmental monitoring (the Arctic Monitoring and Assessment Programme) and will serve as the basis for the IPCC's fifth report, which is expected to be ready by 2014.

Besides Margareta Johansson, Torben Christensen from Lund University also took part in the work.

More information on the report and The Artic as a messenger for global processes - climate change and pollution conference in Copenhagen can be found at: http://amap.no/Conferences/Conf2011/

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by Lund University.

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Ecstasy associated with chronic change in brain function

ScienceDaily (May 3, 2011) — Ecstasy -- the illegal "rave" drug that produces feelings of euphoria and emotional warmth -- has been in the news recently as a potential therapeutic. Clinical trials are testing Ecstasy in the treatment of post-traumatic stress disorder.

But headlines like one in Time magazine's health section in February -- "Ecstasy as therapy: have some of its negative effects been overblown?" -- concern Ronald Cowan, M.D., Ph.D., associate professor of Psychiatry.

His team reports in the May issue of Neuropsychopharmacology that recreational Ecstasy use is associated with a chronic change in brain function.

"There's tension in the fields of psychiatry and psychotherapy between those who think Ecstasy could be a valuable therapeutic that's not being tested because of overblown fears, and those who are concerned about the drug's potentially harmful effects," Cowan said.

"We're not on one side or the other; we're just trying to find out what's going on in the brain -- is there any evidence for long-lasting changes in the brain?"

The message in news reports needs to be accurate, Cowan said. His team's studies suggest that the current message should be: "If you use Ecstasy recreationally, the more you use, the more brain changes you get."

Cowan and his colleagues examined brain activation during visual stimulation, using functional magnetic resonance imaging (fMRI), in subjects who had previously used Ecstasy (but not in the two weeks prior to imaging) and in subjects who had not previously used Ecstasy.

They found increased brain activation in three brain areas associated with visual processing in Ecstasy users with the highest lifetime exposure to the drug. The findings were consistent with the investigators' predictions based on results from animal models: that Ecstasy use is associated with a loss of serotonin signaling, which leads to hyper-excitability (increased activation) in the brain.

The hyper-excitability suggests a loss in brain efficiency, Cowan said, "meaning that it takes more brain area to process information or perform a task."

The investigators found that this shift in brain excitability did not return to normal in subjects who had not used Ecstasy in more than a year.

"We think this shift in cortical excitability may be chronic, long-lasting, and even permanent, which is a real worry," Cowan said, noting that the Ecstasy users in the study are young (18 to 35 years old). "The question is what will happen to their brains as they age over the next 60 years."

Cowan said that the pattern of hyper-excitability is similar to that observed in fMRI studies of individuals at risk for, or with early, Alzheimer's disease.

"I'm not saying that these people are at increased risk for dementia, but that there's a loss of brain efficiency in both recreational Ecstasy use and early Alzheimer's."

The findings suggest that brain hyper-excitability (increased activation in fMRI scans) may be a useful biomarker for Ecstasy-induced neurotoxicity, which the investigators will continue to study.

"Our goal is to be able to let people know whether or not the drug is causing long-term brain damage," Cowan said. "That's really critical because millions of people are using it."

The 2009 National Survey on Drug Use and Health estimated that 14.2 million individuals 12 years or older in the United States had used Ecstasy in their lifetime; 760,000 people had used Ecstasy in the month prior to being surveyed.

Cowan is also interested in determining the doses of Ecstasy that are toxic, and whether there are genetic vulnerabilities to toxicity. If clinical trials show that the drug has therapeutic benefits, it's critical to know the risks, he said.

The research was supported by the National Science Foundation, the National Institute on Drug Abuse, the National Institute of Mental Health, and the National Center for Research Resources.

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by Vanderbilt University Medical Center, via EurekAlert!, a service of AAAS.

Journal Reference:

Amy L Bauernfeind, Mary S Dietrich, Jennifer U Blackford, Evonne J Charboneau, James G Lillevig, Christopher J Cannistraci, Neil D Woodward, Aize Cao, Tristan Watkins, Christina R Di Iorio, Carissa Cascio, Ronald M Salomon, Ronald L Cowan. Human Ecstasy Use is Associated with Increased Cortical Excitability: An fMRI Study. Neuropsychopharmacology, 2011; 36 (6): 1127 DOI: 10.1038/npp.2010.244

Note: If no author is given, the source is cited instead.

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

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