Content Writer ATLAS Maps Rare Four-Way Intersections of the Weak Force at CERN

ATLAS Experiment at CERN has mapped the rare four-way intersections of the weak force, providing new insights into how fundamental particles interact through one of nature’s four fundamental forces. This achievement represents a significant advancement in understanding the weak force’s role in particle physics and its influence on cosmic processes.

The weak force, carried by W and Z bosons, operates at subatomic scales but has profound effects on astronomical phenomena, including the formation of heavy elements and the nuclear processes that power stars. By observing rare multi-boson production processes like WWγ production, where two W bosons and a photon are produced simultaneously, the ATLAS Collaboration has gained deeper insight into the behavior of force carriers under extreme conditions.

In a new analysis of the full LHC Run-2 dataset collected between 2015 and 2018, ATLAS researchers identified events consistent with WWγ production with a statistical significance of 5.9 standard deviations. This level of significance meets the threshold for discovery in particle physics and confirms a previous result from the CMS Collaboration, marking the first such observation by the ATLAS Experiment.

The observation of WWγ production is particularly challenging because it closely resembles more common background processes, such as top-quark-pair production with a photon or Z-boson production associated with photons. Background processes involving misidentified photons further complicate the analysis, requiring sophisticated techniques to isolate the signal.

These multi-boson production processes are among the most sensitive tests of the Standard Model of particle physics. The interactions are precisely predicted by theory, and any deviation in their strengths or rates could indicate the presence of new physics phenomena beyond the current understanding. By measuring these rare processes with high precision, scientists can probe for signs of undiscovered particles or forces.

The ATLAS Collaboration continues to upgrade its detector in preparation for the High-Luminosity Large Hadron Collider (HL-LHC) phase, set to begin in 2030. The HL-LHC will deliver roughly an order of magnitude more data than previous runs, enabling even more precise measurements of the Higgs boson’s properties and enhancing sensitivity to a wide range of new-physics scenarios. To handle this increased data load, ATLAS is implementing major detector upgrades, including a completely new inner tracker, a high-granularity silicon timing detector, and enhancements to the trigger and data-acquisition systems.

These technological advances will allow ATLAS to explore rare interactions with greater precision, further mapping the intersections of the weak force and other fundamental forces. The ongoing work at CERN exemplifies how international scientific collaboration drives progress in understanding the universe at its most fundamental level.