Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

SU professors test boundaries of 'new physics' with discovery of 4-quark hadron

11.04.2014

Physicist Tomasz Skwarnicki confirms existence of exotic hadron with 2 quarks, 2 anti-quarks

Physicists in Syracuse University's College of Arts and Sciences have helped confirm the existence of exotic hadrons—a type of matter that cannot be classified within the traditional quark model.

Their finding is the subject of a forthcoming article, prepared by the Large Hadron Collider beauty (LHCb) Collaboration at CERN in Geneva, Switzerland. (LHCb is a multinational experiment, designed to identify new forces and particles in the universe.) Tomasz Skwarnicki, professor of physics, is one of the paper's lead authors.

"We've confirmed the unambiguous observation of a very exotic state—something that looks like a particle composed of two quarks and two anti-quarks," says Skwarnicki, a specialist in experimental high-energy physics. "The discovery certainly doesn't fit the traditional quark model. It may give us a new way of looking at strong-interaction physics."

... more about:
»CERN »Collider »Hadron »LHCb »Syracuse »collisions »matter »physics »technique

Quarks are hard, point-like objects found within the nucleus of an atom. When quarks combine in threes, they form compound particles known as baryons. Protons are probably the best-known baryons.

Sometimes, quarks interact with corresponding anti-particles (i.e., anti-quarks), which have the same mass but opposite charges. When this happens, they form mesons. These compounds often turn up in the decay of heavy man-made particles, such as those in particle accelerators, nuclear reactors, and cosmic rays.

Mesons, baryons, and other kinds of particles that take part in strong interactions are called hadrons.

This classification remained virtually unchallenged until 2007, when an international team of 400 physicists and engineers known as the Belle Collaboration discovered an exotic particle called Z(4430), which appeared to have two quarks and two anti-quarks.

"Some experts argued that Belle's initial analysis was naïve and prone to arrive at an unjustified conclusion," says Skwarnicki, adding that other exotic states have since been observed. "As a result, many physicists concluded that there was no good evidence to prove this particle was real."

A few years later, another multinational team, known as BaBar, used a more sophisticated analysis technique, only to end up provoking more controversy over the existence of Z(4430). "BaBar didn't prove that Belle's measurements and data interpretations were wrong," Skwarnicki says. "They just felt that, based on their data, there was no need to postulate existence of this particle."

Belle responded with an even more rigorous analysis of the same data set. This time, they found statistically significant evidence for Z(4430), despite the complexity of the analysis and a large number of assumptions made about the particle's production environment.

LHCb, which, for much of the past year, has closely studied its own particle data, used Belle's and BaBar's analysis techniques. In the process, Skwarnicki and his team confirmed that Z(4430) was for real—and an exotic hadron, to boot.

"This experiment is the clincher, showing that particles made up of two quarks and two anti-quarks actually exist," Skwarnicki says. "There used to be less-clear evidence for the existence of such a particle, with one experiment being questioned by another. Now we know this is an observed structure, instead of some reflection or special feature of the data."

Professor Sheldon Stone leads a team of SU researchers at CERN (also known as the European Organization for Nuclear Research) in Geneva.

"We analyzed tens of thousands of meson decays, selected from trillions of collisions in the Large Hadron Collider [the world's largest, most powerful particle accelerator] at CERN," he says. "Because the data sample was so large, it forced us to use statistically powerful analysis that could, in turn, measure properties in an unambiguous manner. It's great to finally prove the existence of something that we had long thought was out there."

Adds Skwarnicki: "Each experiment--Belle, BaBar, and LHCb--analyzed its own data. Although it pertained to the same process, the data was collected at different times, with different colliders, and with different apparatuses for capturing outgoing particles. Our findings are unique to our experiment."

###

Housed in The College, the Department of Physics has been educating students and carrying out research for more than 125 years. Graduate and undergraduate opportunities are available in fields ranging from biological and condensed matter physics, to cosmology and particle physics, to gravitational wave detection and astrophysics.

Rob Enslin | Eurek Alert!
Further information:
http://www.syr.edu/

Further reports about: CERN Collider Hadron LHCb Syracuse collisions matter physics technique

More articles from Physics and Astronomy:

nachricht Upside down and inside out
27.04.2015 | University of Cambridge

nachricht Fast and Accurate 3-D Imaging Technique to Track Optically-Trapped Particles
24.04.2015 | Korea Advanced Institute of Science and 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: Fast and Accurate 3-D Imaging Technique to Track Optically-Trapped Particles

KAIST researchers published an article on the development of a novel technique to precisely track the 3-D positions of optically-trapped particles having complicated geometry in high speed in the April 2015 issue of Optica.

Daejeon, Republic of Korea, April 23, 2015--Optical tweezers have been used as an invaluable tool for exerting micro-scale force on microscopic particles and...

Im Focus: NOAA, Tulane identify second possible specimen of 'pocket shark' ever found

Pocket sharks are among the world's rarest finds

A very small and rare species of shark is swimming its way through scientific literature. But don't worry, the chances of this inches-long vertebrate biting...

Im Focus: Drexel materials scientists putting a new spin on computing memory

Ever since computers have been small enough to be fixtures on desks and laps, their central processing has functioned something like an atomic Etch A Sketch, with electromagnetic fields pushing data bits into place to encode data.

Unfortunately, the same drawbacks and perils of the mechanical sketch board have been just as pervasive in computing: making a change often requires starting...

Im Focus: Exploding stars help to understand thunderclouds on Earth

How is lightning initiated in thunderclouds? This is difficult to answer - how do you measure electric fields inside large, dangerously charged clouds? It was discovered, more or less by coincidence, that cosmic rays provide suitable probes to measure electric fields within thunderclouds. This surprising finding is published in Physical Review Letters on April 24th. The measurements were performed with the LOFAR radio telescope located in the Netherlands.

How is lightning initiated in thunderclouds? This is difficult to answer - how do you measure electric fields inside large, dangerously charged clouds? It was...

Im Focus: On the trail of a trace gas

Max Planck researcher Buhalqem Mamtimin determines how much nitrogen oxide is released into the atmosphere from agriculturally used oases.

In order to make statements about current and future air pollution, scientists use models which simulate the Earth’s atmosphere. A lot of information such as...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

HHL Energy Conference on May 11/12, 2015: Students Discuss about Decentralized Energy

23.04.2015 | Event News

“Developing our cities, preserving our planet”: Nobel Laureates gather for the first time in Asia

23.04.2015 | Event News

HHL's Entrepreneurship Conference on FinTech

13.04.2015 | Event News

 
Latest News

Strong Evidence – New Insight in Muscle Function

27.04.2015 | Life Sciences

The Future of Oil and Gas: Last of Her Kind

27.04.2015 | Power and Electrical Engineering

Tiny Lab Devices Could Attack Huge Problem of Drug-Resistant Infections

27.04.2015 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>