Skip to main content
  • Home
  • About
  • Faculty Experts
  • For The Media
  • Videos
  • Topics
    • Alumni
    • Events
    • Faculty
    • Library
    • Research
    • Students
    • All Topics
  • Contact
  • Submit
  • All News
  • Arts & Culture
  • Business & Economy
  • Campus & Community
  • Health & Society
  • Media, Law & Policy
  • STEM
  • Veterans
  • |
  • Alumni
  • The Peel
  • Athletics
Sections
  • All News
  • Arts & Culture
  • Business & Economy
  • Campus & Community
  • Health & Society
  • Media, Law & Policy
  • STEM
  • Veterans
  • |
  • Alumni
  • The Peel
  • Athletics
  • Home
  • About
  • Faculty Experts
  • For The Media
  • Videos
  • Topics
    • Alumni
    • Events
    • Faculty
    • Library
    • Research
    • Students
    • All Topics
  • Contact
  • Submit

Professors Test Boundaries of ‘New Physics’ with Discovery of Four-Quark Hadron

Monday, April 14, 2014, By Rob Enslin
Share
research
A view of the LHCb experiment at an underground point on the Large Hadron Collider (LHC). The prominent tube is the LHC beam pipe, where protons circulate at close to the speed of light. (Photo by Anna Pantelia/CERN)

A view of the LHCb experiment at an underground point on the Large Hadron Collider (LHC). The prominent tube is the LHC beam pipe, where protons circulate at close to the speed of light. (Photo by Anna Pantelia/CERN)

Physicists in The 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.”

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.

Tomasz Skwarnicki

Tomasz Skwarnicki

“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.”

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

Sheldon Stone

Sheldon Stone

“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.”

  • Author

Rob Enslin

  • Recent
  • Important Public Health Update: Barnes Center Will Pause Distribution of J&J Vaccine
    Tuesday, April 13, 2021, By News Staff
  • ‘Should the COVID-19 Vaccine Be Required for the Military?’
    Tuesday, April 13, 2021, By Lily Datz
  • Student Assembly of Interfaith Leaders Highlights Importance of Interfaith Collaboration
    Tuesday, April 13, 2021, By News Staff
  • LLL Provides Students a Virtual Taste of Italian Food and Culture
    Monday, April 12, 2021, By Dan Bernardi
  • Department of Drama Releases Digital Senior Showcase
    Monday, April 12, 2021, By Erica Blust

More In Uncategorized

“Why aren’t NY farm workers in the Covid-19 vaccine line?”

Laura-Anne Minkoff-Zern, associate professor of food studies in Falk College, was interviewed for the Syracuse.com story “Why aren’t NY farm workers in the Covid-19 vaccine line?” Minkoff-Zern, an expert on the intersections of food and social justice, comments on the…

“Biden to broaden US-Mexican relations, keep immigration at top.”

Gladys McCormick, associate professor of history in the Maxwell School, was quoted in the Al Jazeera story “Biden to broaden US-Mexican relations, keep immigration at top.” McCormick, an expert on US-Mexico relations, believes that Mexican president Andres Manuel Lopez Obrador…

“The long game: COVID changed the way we play, watch, cheer”

Dennis Deninger, professor of practice in Falk College and the Newhouse School, was quoted in the Associated Press story “The long game: COVID changed the way we play, watch, cheer.” Deninger, an expert on sports television and media, believes that…

“Meghan Markle and Prince Harry Ratings: Oprah Interview Draws 17.1 Million Viewers.”

Robert Thompson, Trustee Professor of television, radio and film and director of the Bleier Center for Television and Popular Culture in the Newhouse School, was quoted in The Wall Street Journal story “Meghan Markle and Prince Harry Ratings: Oprah Interview…

“7 Women Scientists Who Defied the Odds and Changed Science Forever.”

Christa Kelleher, assistant profession of earth environmental science in the College of Arts and Sciences, was quoted in the Newsweek article “7 Women Scientists Who Defied the Odds and Changed Science Forever.” Kelleher, an expert on hydrology, comments particularly on…

Subscribe to SU Today

If you need help with your subscription, contact sunews@syr.edu.

Connect With Us

  • Twitter
  • Facebook
  • Instagram
  • Youtube
  • LinkedIn
Social Media Directory

For the Media

Find an Expert Follow @SyracuseUNews
  • Facebook
  • Instagram
  • Youtube
  • LinkedIn
  • @SyracuseU
  • @SyracuseUNews
  • @SUCampus
  • Social Media Directory
  • Accessibility
  • Privacy
  • Campus Status
  • Syracuse.edu
© 2021 Syracuse University News. All Rights Reserved.