After months of winter hibernation the world’s most powerful particle accelerator is once again smashing protons and taking data. The Large Hadron Collider will run around the clock for the next six months and produce roughly 2 quadrillion high-quality proton collisions, six times more than in 2015 and just shy of the total number of collisions recorded during the nearly three years of the collider’s first run.
Between 2010 and 2013 the LHC produced proton-proton collisions with 8 teraelectronvolts of energy. In the spring of 2015, after a two-year shutdown, LHC operators ramped up the collision energy to 13 TeV. This increase in energy enables scientists to explore a new realm of physics that was previously inaccessible. Run II collisions also produce Higgs bosons – the groundbreaking particle discovered in LHC Run I – 25 percent faster than Run I collisions and increase the chances of finding new massive particles by more than 40 percent.
During this run, University of Maryland physicists will continue looking for new particles, including those that make up dark matter. Although the nature of dark matter and its counterpart, dark energy, remain a complete mystery, taken together they make up a total of around 95 percent of the universe.
The signature that will indicate the dark matter particle is known as missing transverse energy. UMD physicists are very familiar with this measurement, as they are a leading institution in the missing transverse energy group of the LHC’s Compact Muon Solenoid (CMS) detector.
Members of the Maryland group will also study collisions of nuclei with the CMS detector as well as the details of the interactions of the particles responsible for the sun’s energy. UMD physicists will also harness the LHC to investigate the origin of matter-antimatter asymmetry in the universe. When the Big Bang created matter, it also created an equal quantity of antimatter, made up of particles with identical mass but an opposite electrical charge. For as-yet unknown reasons, antimatter is no longer common in the universe, but can be recreated in particle accelerators such as the LHC.
UMD’s Hassan Jawahery leads a group that will use the LHCb detector to study the “beauty” or “bottom” quark— hence the “b” in the detector’s name. The collider will also produce the antimatter counterpart to the beauty quark. Comparing the properties of these two complementary particles could reveal laws of nature that treat matter and antimatter differently.
Key members of the University of Maryland LHC Team are available to comment on their work:
Drew Baden, Chair and Professor
Alberto Belloni, Assistant Professor
Sarah Eno, Professor
Nicholas Hadley, Professor
Hassan Jawahery, Distinguished University Professor and Gus T. Zorn Professor
Alice Mignery, Professor
Andris Skuja, Professor