Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Virginia Tech partner in discovery of quark interaction

01.07.2005


Physics researchers working at the High Energy Accelerator Research Organization (KEK) Laboratory in Japan have observed a new type of interaction among the most fundamental of particles, the quark. The scientists reported at the Symposium on Lepton-Photon Interactions at High Energies, June 30-July 5 in Uppsala, Sweden, that they had produced first evidence of a beauty quark converting to the lightest of quarks, the down quark.


It was proven that B meson decays into a lighter meson such as _ or _ with an accompanying photon. This is an evidence for bÆd transition.


It was also confirmed that B meson disintegrates into two K mesons with a probability of the order of 10-6. This is also an evidence for bÆd transition.



"Observation of this very rare phenomenon allows us to study if this occurs only through the so-called penguin process (a two-step transition wherein the beauty quark momentarily transforms into the top quark that subsequently transforms into the down quark) as predicted by the standard theory, or through some hitherto unobserved way," said Leo Piilonen, Virginia Tech physics professor and a member of the Belle experiment’s research team.

Virginia Tech is a founding institution in the Belle experiment that studies the properties of the beauty (b) quark at the KEK Laboratory. The Belle experiment studies the decay patterns of the b-quark to search for clues on how the universe is constructed. Using a the electron-positron colliding beam accelerator, the so-called B Factory has made many important contributions to our understanding of nature at its most fundamental level, including those just announced by Professor Kazuo Abe of the KEK Laboratory in his plenary talk in Sweden. (See release posted at http://belle.kek.jp/).


Virginia Tech physics graduate student Debabrata Mohapatra worked on the analysis that led to the results. He is at the KEK laboratory this summer and will return to Blacksburg to complete his dissertation in August.

Quarks are the most fundamental constituents of material, and it is widely known that six types exist in nature. Piilonen explains that the purpose of the B Factory is to produce an enormous number of the second heaviest, called the b quark, and clarify the fundamental laws of the universe by detailed studies of its behavior. Previous findings include the discovery of many new particle states, discovery of the violation of particle-antiparticle symmetry in b quark decays, and the experimental confirmation of the Kobayashi-Maskawa theory, which characterizes the properties of quarks and predicted this symmetry violation.

In the last year, the performance of the KEKB accelerator has continued to improve, reaching the world’s highest luminosity of 1.5x1034 /cm2/sec, and delivering 390 million pairs of B and anti-B mesons to the Belle experiment. (These mesons contain the b quark or its antiparticle.) The Belle group has investigated the decays of these B mesons in detail, and has observed a new type of interaction wherein the b quark turns into one of the lightest quarks, the d quark. This phenomenon was confirmed by finding 35 events where the B meson decays into either a rho or an omega meson with an accompanying photon, and 30 events where the B meson disintegrates into two K mesons.

"Observation of this very rare phenomenon allows us to study if this occurs only through the penguin process as predicted by the standard theory, or through some hitherto unobserved way," Piilonen said.

"This opens an exciting new window into our understanding of elementary particle physics: for example, new physics models that incorporate so-called supersymmetry also predict b to d quark transitions, and our announced observation will provide valuable feedback to these models," he continued. "On the other hand, if we assume that the standard model holds, then our observation will provide a novel measurement of one of the coarsely measured parameters in the Kobayashi-Maskawa theory (Vtd), and lead to a more complete understanding of the standard model."

Susan Trulove | EurekAlert!
Further information:
http://www.vt.edu

More articles from Physics and Astronomy:

nachricht Space radiation won't stop NASA's human exploration
18.10.2017 | NASA/Johnson Space Center

nachricht Study shows how water could have flowed on 'cold and icy' ancient Mars
18.10.2017 | Brown University

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: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Osaka university researchers make the slipperiest surfaces adhesive

18.10.2017 | Materials Sciences

Space radiation won't stop NASA's human exploration

18.10.2017 | Physics and Astronomy

Los Alamos researchers and supercomputers help interpret the latest LIGO findings

18.10.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>