CERN’s Large Hadron Collider (LHC) physicists, through the LHCb experiment, have unveiled a groundbreaking deuteron-like particle known as Ξcc⁺. This remarkable particle, composed of two charm quarks and one down quark, offers scientists a novel means to explore the formidable forces binding the fundamental constituents of matter.
Artist’s impression of the double charm baryon Ξcc⁺ containing two charm quarks and one down quark. Image credit: CERN.
Quarks, the fundamental building blocks of matter, exist in six distinct flavors: up, down, charm, strange, top, and bottom.
Typically, quarks combine in pairs or groups of three to form mesons and baryons. While protons are stable, most hadrons (mesons and baryons) are fleeting, vanishing almost immediately upon creation, making detection a challenge.
To facilitate their production, high-energy particles are collided within machines like the LHC.
These unstable hadrons decay rapidly, yet the resultant more stable particles can be detected, enabling scientists to infer the properties of the original particles.
With this discovery, the total count of hadrons identified in LHC experiments has risen to 80.
“This marks the first new particle identified following the LHCb detector upgrades completed in 2023, and it is the second baryon discovered that features two heavy quarks, echoing the initial observation made nearly a decade ago,” stated LHCb spokesperson Dr. Vincenzo Vagnoni.
“The implications of this result will aid theorists in testing quantum chromodynamics models, enhancing our understanding of strong forces that unify quarks to form conventional baryons and mesons, as well as more exotic structures like tetraquarks and pentaquarks.”
In 2017, the LHCb team reported a similar particle containing two charm quarks and an up quark, which differs from the newly discovered particle solely by having a down quark.
Despite their similarities, the predicted lifetimes for the new particles are up to six times shorter than their counterparts due to intricate quantum effects, complicating their observation.
By scrutinizing data from proton-proton collisions captured by the LHCb detector during the LHC’s third operation phase, physicists confirmed a new baryon with a statistical significance of 7 sigma, surpassing the 5 sigma threshold needed for a discovery claim.
“This significant milestone exemplifies how LHCb’s unique capabilities contribute to its success,” remarked CERN Director-General Mark Thomson.
“This highlights the direct link between experimental upgrades at CERN and the new discoveries, paving the way for the pioneering science anticipated from the High-Luminosity LHC.”
“These accomplishments were made possible due to the extraordinary performance of CERN’s accelerator complex and the unwavering commitment of the scientists involved in the LHCb experiment.”
Source: www.sci.news
