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 Molecule flash mob
19.01.2017 | Technische Universität Wien

nachricht Magnetic moment of a single antiproton determined with greatest precision ever
19.01.2017 | Johannes Gutenberg-Universität Mainz

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: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

New Study Will Help Find the Best Locations for Thermal Power Stations in Iceland

19.01.2017 | Earth Sciences

Not of Divided Mind

19.01.2017 | Life Sciences

Molecule flash mob

19.01.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>