Evidence for light-by-light scattering in heavy-ion collisions with the ATLAS detector at the LHC
Physicists have used collisions between lead ions to observe light being scattered by light, paving the way for a better understanding of the properties of matter, according to a study published in Nature Physics.
The phenomenon, called light-by-light scattering, is impossible in classical physics because particles of light, or photons, carry no charge. Quantum physics predicts the possibility of photon-photon interactions, but so far their detection has remained elusive.
Using data from the ATLAS detector at the Large Hadron Collider, an international team of physicists, including researchers from the University of Cape Town, sifted through more than four billion events resulting from the collisions of lead ions and have identified 13 that could be two photons interacting with each other.
This finding could lead to more precise measurements of light-by-light scattering, and could yield the discovery of new particles.
- Nature Physics 13, 852–858 (2017). doi: 10.1038/nphys4208