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 What happens when we heat the atomic lattice of a magnet all of a sudden?
17.07.2018 | Forschungsverbund Berlin

nachricht Subaru Telescope helps pinpoint origin of ultra-high energy neutrino
16.07.2018 | National Institutes of Natural Sciences

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: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Microscopic trampoline may help create networks of quantum computers

17.07.2018 | Information Technology

In borophene, boundaries are no barrier

17.07.2018 | Materials Sciences

The role of Sodium for the Enhancement of Solar Cells

17.07.2018 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>