Manchester Scientists Uncover New Particle, Echoing Rutherford’s Legacy
Scientists at The University of Manchester have been instrumental in the discovery of a new subatomic particle, the Ξcc⁺ (Xi-cc-plus), at CERN’s Large Hadron Collider (LHC). This heavy proton-like particle, composed of two charm quarks and one down quark, represents the first particle identified using the upgraded LHCb detector.
The Significance of the Ξcc⁺ Discovery
The Ξcc⁺ belongs to the same family as the proton, a particle first identified in Manchester by Ernest Rutherford and his team between 1917, and 1919. Whereas a proton contains up quarks, the Ξcc⁺ substitutes these with heavier charm quarks. This discovery confirms predictions based on a related particle, the Ξcc⁺⁺, and resolves a two-decade-long debate surrounding earlier, unconfirmed observations of this type of particle.
UK Leadership in the LHCb Upgrade
The upgrade of the LHCb detector was a major international collaboration involving over 1,000 researchers from 20 countries. The United Kingdom made the largest national contribution to this effort, with the University of Manchester playing a leading role. Professor Chris Parkes, head of the University’s Department of Physics and Astronomy, led the international collaboration during the installation and initial operation of the upgraded detector, overseeing the UK’s involvement for over ten years.
Manchester’s Technological Contributions
The Manchester LHCb team designed and built crucial components of the upgraded tracking system, specifically silicon pixel detector modules assembled at the University’s Schuster Building. These modules are essential for accurately tracking particle decays and identifying signals like the Ξcc⁺. Dr. Stefano De Capua led the production of these silicon detector modules, describing the detector’s capability to capture 40 million particle images per second.
“The detector is a form of ‘camera’ that images the particles produced at the LHC and takes photographs 40 million times per second. It utilises a custom-designed silicon chip that also has a variant for use in medical imaging applications,” explained Dr. De Capua.
How the Particle Was Detected
Researchers identified the Ξcc⁺ by observing its decay into three lighter particles: Λc⁺ K⁻ π⁺. These decay events were recorded during proton-proton collisions at the LHC in 2024, the first year the upgraded LHCb experiment operated at full capacity. A clear signal of approximately 915 events was measured at a mass of 3619.97 MeV/c2.
Future Directions: LHCb Upgrade 2 and Beyond
The University of Manchester will continue to be a key player in the next phase of the LHC program, known as LHCb Upgrade 2. This upgrade will leverage the High-Luminosity LHC accelerator to collect more data and investigate rare particles in greater detail. This will allow scientists to further refine their understanding of matter-antimatter asymmetry and the fundamental forces governing the universe.
The Legacy of Particle Physics at Manchester
This discovery builds upon a rich history of particle physics research at Manchester. In the 1950s, university scientists were the first to identify a member of the Ξ (Xi) particle family, establishing a foundation for subsequent breakthroughs.
FAQ
What is the Ξcc⁺ particle?
It’s a new subatomic particle, a heavier relative of the proton, made up of two charm quarks and one down quark.
What role did the University of Manchester play?
Manchester scientists designed and built key components of the upgraded LHCb detector and led the international collaboration during its installation and operation.
Why is this discovery important?
It confirms theoretical predictions, resolves a long-standing mystery, and showcases the capabilities of the upgraded LHCb detector.
What is the LHCb detector designed to study?
The LHCb experiment is designed to study particles containing b and c quarks, aiming to understand the differences between matter and antimatter.
How does the LHCb detector work?
It acts like a high-speed camera, taking pictures of particle collisions approximately 25 nanoseconds apart.
What is the next step for the LHCb experiment?
The LHCb Upgrade 2 will utilize the High-Luminosity LHC to gather more data and explore rare particles in greater detail.
