From looking at the products of highly energetic particle collisions at the Large Hadron Collider’s enormous ATLAS detector to measuring the faint signals from the cosmic microwave background at the South Pole, Argonne researchers explore the elementary constituents of matter and energy, the interactions between them, and the ultimate nature of space and time. High Energy Physics Division engages in this research through a program that combines experiment and theory to further scientific discovery, along with a program that advances accelerator technology, instrumentation technology, and cutting-edge scientific computing to enable new breakthroughs.
To build the next generation of world-class particle accelerators – one even more powerful than the Large Hadron Collider in Switzerland – scientists will need to either create an extraordinarily large machine or radically rethink the basic physics of the acceleration mechanism and of the properties of the materials that underpin the functioning of the accelerator.
ATLAS is one of the major particle detector experiments being performed at the Large Hadron Collider (LHC). The ATLAS collaboration consists of more than 3,000 scientists who have undertaken the search for new discoveries based upon the head-on collisions of the highest energy protons currently available worldwide.
Cosmology, the study of the evolution of the Universe, and of its constituents, has made enormous strides in the last thirty years. At Argonne, scientists study the cosmic background radiation, a remnant of the early hot phase of the Universe, as well as dark matter, the dominant form of matter in the Universe, and the mysterious dark energy, which is causing the expansion of the Universe to speed up.
The development of new instrumentation, particularly detector technology, provides a common thread that links together a wide range of high energy physics projects and programs. In order to enable the next generation of experiments, we need ways to build sensitive detectors with fast response that can be fabricated economically.
One avenue to search for particles too heavy to be discovered directly at the energies available at the Large Hadron Collider is to investigate the properties of known particles with great precision. The muon, a heavy cousin of the electron, is well suited for such precision studies due to its relatively long lifetime and large mass.
Experimental neutrino physics is focused on the measurements of mass and other properties of neutrinos that may have profound consequences for particle physics and cosmology. Over the last few decades, researchers have accumulated experimental evidence on various properties of neutrinos, including their interaction with other types of matter, and how these ghostly particles propagate over long distances, while oscillating between different neutrino types, called flavors.
Much of the work in high energy physics concentrates on the interplay between theory and experiment. The theory group of Argonne's High Energy Physics Division performs high-precision calculations within our current understanding of particle physics, the Standard Model, interprets experimental data in terms of physics both within and beyond the Standard Model, and makes predictions for new, well-motivated experimental searches that attempt to provide answers to open questions.