Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Indiana University scientists first to detect rare nuclear fusion violating charge symmetry


This symmetry violation makes hydrogen possible, a requirement for life

Scientists at the Indiana University Cyclotron Facility in Bloomington have made the first unambiguous detection of a rare process, the fusion of two nuclei of heavy hydrogen to form a nucleus of helium and an uncharged pion. The pion is one of the subatomic particles responsible for the strong force that holds every nucleus together. The achievement will be announced Saturday (April 5) at the meeting of the American Physical Society in Philadelphia.

"Scientists have searched for this rare fusion process since the 1950s," said IU physicist Edward Stephenson, the leader of the research team. "The process would not happen at all if nature did not allow a small violation of what is known as charge symmetry. If this symmetry violation had happened to be in the other direction, hydrogen would not have survived after the Big Bang, and the universe would not have the hydrogen fuel that keeps stars shining, including our sun, making human life possible. Sometimes large consequences hang on delicate balances in nature."

One effect of this charge symmetry violation is that the neutron is slightly heavier than its charged partner, the proton. As a result, isolated neutrons decay into protons in about 10 minutes. "If the charge symmetry violation had been in the other direction instead, and if the proton had been heavier than the neutron by the same slight amount, protons would have decayed into neutrons and hydrogen could not have survived," Stephenson explained.

The rate at which the rare fusion process occurs is expected to be a key piece of information in finding the cause for this violation of charge symmetry, he said. Theorists have proposed that the violation originates with quarks, the small particles that are found inside protons and neutrons.

"The rate of the process will tell scientists how much of the violation comes from the fact that quarks carry small electrical charges, and how much comes from the difference in mass between the two types of quarks found inside neutrons and protons," Stephenson said.

The IU team used the electron-cooled storage ring at the cyclotron laboratory to focus a beam of heavy hydrogen onto a target of the same material. The high precision of the beam allowed them to use just enough energy to make the uncharged pion without producing unwanted heavier particles. Sensitive detectors tracked the helium nuclei and captured the two photons or particles of light that are produced when the pion decays.

The team worked around the clock for two months, seeing at most only five of the rare events per day, Stephenson said. However, the several dozen events that they collected will be enough to allow scientists to test their theories about the violation of charge symmtery.

Their research was supported by a grant from the National Science Foundation.

For more information, contact Stephenson at 812-855-5469 or

Hal Kibbey | EurekAlert!
Further information:

More articles from Physics and Astronomy:

nachricht Researchers at Fraunhofer monitor re-entry of Chinese space station Tiangong-1
21.03.2018 | Fraunhofer-Institut für Hochfrequenzphysik und Radartechnik FHR

nachricht Taming chaos: Calculating probability in complex systems
21.03.2018 | American Institute of Physics

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Researchers Discover New Anti-Cancer Protein

An international team of researchers has discovered a new anti-cancer protein. The protein, called LHPP, prevents the uncontrolled proliferation of cancer cells in the liver. The researchers led by Prof. Michael N. Hall from the Biozentrum, University of Basel, report in “Nature” that LHPP can also serve as a biomarker for the diagnosis and prognosis of liver cancer.

The incidence of liver cancer, also known as hepatocellular carcinoma, is steadily increasing. In the last twenty years, the number of cases has almost doubled...

Im Focus: Researchers at Fraunhofer monitor re-entry of Chinese space station Tiangong-1

In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.

Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...

Im Focus: Alliance „OLED Licht Forum“ – Key partner for OLED lighting solutions

Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.

They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...

Im Focus: Mars' oceans formed early, possibly aided by massive volcanic eruptions

Oceans formed before Tharsis and evolved together, shaping climate history of Mars

A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...

Im Focus: Tiny implants for cells are functional in vivo

For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.

In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Virtual reality conference comes to Reutlingen

19.03.2018 | Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

Latest News

Generation of a Stable Biradical

22.03.2018 | Life Sciences

Scientists develop a room temperature maser to amplify weak signals

22.03.2018 | Life Sciences

Jacobs University supports new mapping of Mars, Mercury and the Moon

22.03.2018 | Earth Sciences

Science & Research
Overview of more VideoLinks >>>