Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

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

07.04.2003


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 stephens@iucf.indiana.edu.

Hal Kibbey | EurekAlert!
Further information:
http://newsinfo.iu.edu/

More articles from Physics and Astronomy:

nachricht Hubble sees Neptune's mysterious shrinking storm
16.02.2018 | NASA/Goddard Space Flight Center

nachricht Supermassive black hole model predicts characteristic light signals at cusp of collision
15.02.2018 | Rochester Institute of Technology

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: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

Im Focus: Hybrid optics bring color imaging using ultrathin metalenses into focus

For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.

But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...

Im Focus: Stem cell divisions in the adult brain seen for the first time

Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.

The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...

Im Focus: Interference as a new method for cooling quantum devices

Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters

Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...

Im Focus: Autonomous 3D scanner supports individual manufacturing processes

Let’s say the armrest is broken in your vintage car. As things stand, you would need a lot of luck and persistence to find the right spare part. But in the world of Industrie 4.0 and production with batch sizes of one, you can simply scan the armrest and print it out. This is made possible by the first ever 3D scanner capable of working autonomously and in real time. The autonomous scanning system will be on display at the Hannover Messe Preview on February 6 and at the Hannover Messe proper from April 23 to 27, 2018 (Hall 6, Booth A30).

Part of the charm of vintage cars is that they stopped making them long ago, so it is special when you do see one out on the roads. If something breaks or...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Fingerprints of quantum entanglement

16.02.2018 | Information Technology

'Living bandages': NUST MISIS scientists develop biocompatible anti-burn nanofibers

16.02.2018 | Health and Medicine

Hubble sees Neptune's mysterious shrinking storm

16.02.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>