Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

IU physicist leads discovery of new particle: '4-flavored' tetraquark

03.03.2016

Research led by Indiana University physicist Daria Zieminska has resulted in the first detection of a new form of elementary particle: the "four-flavored" tetraquark.

Zieminska, a senior scientist in the IU Bloomington College of Arts and Sciences' Department of Physics, is a lead member of the team responsible for the particle's detection by the DZero Collaboration at the U.S. Department of Energy's Fermi National Laboratory, which announced the discovery Feb. 25.


The new particle is the first tetraquark to contain four quarks of different "flavors."

Credit: Fermilab

She also delivered the first scientific seminar on the particle and is an author on a paper submitted to Physics Review Letters, the premier journal in physics, describing the tetraquarks' observation.

"For most of the history of quarks, it's seemed that all particles were made of either a quark and an antiquark, or three quarks; this new particle is unique -- a strange, charged beauty," said Zieminska, who has been a member of the DZero experiment since the project's establishment in 1985. "It's the birth of a new paradigm. Particles made of four quarks -- specifically, two quarks and two antiquarks -- is a big change in our view of elementary particles."

The results could also affect scientists' understanding of "quark matter," the hot, dense material that existed moments after the Big Bang, and which may still exist in the super-dense interior of neutron stars.

Quarks are the building blocks that form subatomic particles, the most familiar of which are protons and neutrons, each composed of three quarks. There are six types, or "flavors," of quarks: up, down, strange, charm, bottom and top. Each of these also has an antimatter counterpart.

A tetraquark is a group of four quarks, the first evidence for which was recorded by scientists on the Belle experiment in Japan in 2008. But the new tetraquark is the first quark quartet to contain four different quark flavors: up, down, strange and bottom.

Currently, Zieminska leads the "heavy flavor" group of the DZero experiment, which encompasses the study of all particles containing one or more "heavy quarks," including the new tetraquark, dubbed X(5568) for its mass of 5568 Megaelectronvolts, roughly 5.5 times the mass of a proton. The DZero experiment is led by Dmitri Denisov, a staff scientist at the U.S. Department of Energy's Fermilab.

"Daria was the lead person on the tetraquark observation and performed calculations, cross-checking and other work required to answer the hundreds of questions of the rest of the team," said Denisov, co-spokesman for the DZero experiment. "She was an active participant in the design and construction of the experiment and in the collection of the data."

The DZero experiment is also responsible for other fundamental physics discoveries, including the first observation, with the Collider-Detector at Fermilab experiment, of the elusive Higgs boson particle decaying into bottom quarks.

Other IU scientists engaged in the DZero project include the late Andrzej Zieminski, former professor of physics at IU Bloomington, who also joined the project in 1985, and Rick Van Kooten, IU vice provost for research, who joined in 2002 during "phase 2" of the project, which involved upgrades to the detector partially constructed at IU. Hal Evans, professor, and Sabine Lammers, associate professor, both at IU, also contributed to the upgraded detector.

DZero is one of two experiments collecting data from Fermilab's Tevatron proton-antiproton collider, once the most powerful particle accelerator in the world, officially retired in 2011. Zieminska and colleagues uncovered the existence of X(5568) based on analysis of billions of previously recorded events from these collisions.

As with other discoveries in physics, Zieminska said the new tetraquark's discovery was a surprise. Alexey Drutskoy, a colleague at Russia's National Research Nuclear University, spotted indications of the tetraquark signal in summer 2015, after which Zieminska joined him in the hunt. Only after performing multiple cross-checks, in collaboration with Alexey Popov, another Russian colleague, did the team confirm they were observing evidence for a new particle.

Although nothing in nature forbids the formation of a tetraquark, four-quark states are rare and not nearly as well understood as two- and three-quark states. Zieminska and colleagues plan to deepen their understanding of the tetraquark by measuring various properties of the particle, such as the ways it decays or how much it spins on its axis.

The discovery of the tetraquark also comes on the heels of the first observation of a pentaquark -- a five-quark particle -- announced last year by CERN's LHCb experiment at the Large Hadron Collider.

Zieminska is also a member of the ATLAS Experiment at CERN, the European Organization for Nuclear Research.

A total of 75 institutions from 18 countries are members of the DZero Collaboration.

Media Contact

Kevin D. Fryling
kfryling@iu.edu
812-856-2988

 @IndianaResearch

http://newsinfo.iu.edu 

Kevin D. Fryling | EurekAlert!

More articles from Physics and Astronomy:

nachricht Shape matters when light meets atom
05.12.2016 | Centre for Quantum Technologies at the National University of Singapore

nachricht Climate cycles may explain how running water carved Mars' surface features
02.12.2016 | Penn State

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: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

NASA's AIM observes early noctilucent ice clouds over Antarctica

05.12.2016 | Earth Sciences

Shape matters when light meets atom

05.12.2016 | Physics and Astronomy

Researchers uncover protein-based “cancer signature”

05.12.2016 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>