Physicists from the LHCb collaboration at CERN’s Large Hadron Collider (LHC) have successfully detected the elusive Ωcc⁺ baryon. This particle, which contains two charm quarks and one strange quark, completes the long-sought family of doubly-charmed baryons, first predicted over half a century ago.
Artist’s impression of the Ωcc⁺ baryon, showcasing its dual charm. Image credit: Daniel Dominguez / CERN.
“Quarks are the fundamental building blocks of matter,” stated Dr. Paula Collins, deputy spokesperson for the LHCb collaboration.
“There are six types of quarks: up, down, charm, strange, top, and bottom. These combine into pairs or triplets, recognized as mesons and baryons, respectively.”
“Sixty years ago, as experiments began revealing the quark structure of matter, researchers started developing theoretical models to classify how quarks form into composite particles.”
“Scientists were soon able to predict the properties of particles that had yet to be discovered.”
“The discovery of a new particle at Brookhaven National Laboratory in 1964 marked a significant turning point.”
“This particle, comprised of three strange quarks, was previously predicted by theorists, and its experimental validation confirmed the robustness of these theoretical models.”
“In 1974, another groundbreaking discovery was made with the identification of the fourth quark, the charm quark,” researchers noted.
“This prompted theorists to expand the model to include numerous potential quark combinations.”
“These predictions encompassed baryons with dual charm properties.”
“Such particles consist of two charm quarks along with a third up, down, or strange quark.”
“Physicists are particularly intrigued by this group of particles because the significant mass differences among quarks can shed light on the strong forces binding quarks into composite structures.”
“Unfortunately, prior experiments lacked the capability to generate baryons with dual charm due to insufficiently sensitive instruments.”
Illustration of the production and detection of the dual charm Ωcc⁺ baryons in the LHCb experiment. Image credit: CERN.
The LHCb physicists discovered the first of these doubly-charmed baryons in 2017 and the second earlier this year.
The detection of Ωcc⁺ marks the third and final member of this particle family, with data analyzed from high-energy proton-proton collisions at the LHC in 2024.
These collisions produced new doubly-charmed baryons, which are short-lived, traveling only a few millimeters through the detector before decaying into more stable particles.
The LHCb team tracked the traces these particles left on the detector back to their origin.
This revealed the distinctive signature of a new short-lived particle with a mass approximately four times that of a proton.
“This is a beautiful and historically significant moment,” Dr. Collins remarked.
“Among the 85 composite particles discovered so far at the LHC, these three doubly-charmed baryons stand out.”
“They decay under weak forces and have sufficiently long lifetimes to produce measurable flight distances in our experiments.”
“This groundbreaking discovery was made possible due to the upgraded LHCb detectors, which have advanced capabilities for tracking and identifying particles.”
Source: www.sci.news
