Building on its extensive commitment to CERN, the University of Rochester team recently obtained “incredibly precise” measurements of the electroweak mixing angle, a crucial part of the Standard Model of particle physics. Credits: Samuel Joseph Hertzog; Julien Marius Ordan
Researchers from the University of Rochester, working with the CMS collaboration at
” data-gt-translate-attributes=”({“attribute”:”data-cmtooltip”, “format”:”html”})” tabindex=”0″ role=”link”>CERNhave made significant progress in measuring the electroweak mixing angle, improving our understanding of the Standard Model of particle physics.
Their work helps explain the fundamental forces of the universe, supported by experiments such as those conducted at the Large Hadron Collider, which explore conditions similar to those following the fall of the Earth.
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Unveiling Universal Mysteries
In their quest to decode the mysteries of the universe, researchers at the University of Rochester have been involved for decades in international collaborations within the European Organization for Nuclear Research, more commonly known as CERN.
Building on its strong involvement at CERN, particularly within the CMS (Compact Muon Solenoid) collaboration, the Rochester team, led by Arie Bodek, George E. Pake Professor of Physics, recently took a revolutionary step. Their achievements focus on measuring the electroweak mixing angle, a crucial part of the Standard Model of particle physics. This model describes how particles interact and accurately predicts a multitude of phenomena in physics and astronomy.
“Recent measurements of the electroweak mixing angle are incredibly precise, calculated from proton collisions at CERN, and add to the understanding of particle physics,” says Bodek.
The CMS Collaboration brings together members of the particle physics community from around the world to better understand the fundamental laws of the universe. In addition to Bodek, the Rochester cohort of the CMS Collaboration includes principal investigators Regina Demina, professor of physics, and Aran Garcia-Bellido, associate professor of physics, as well as postdoctoral research associates and graduate and undergraduate students.
Researchers from the University of Rochester have a long history of working at CERN as part of the Compact Muon Solenoid (CMS) collaboration, including playing a key role in the discovery of the Higgs boson in 2012. Credits: Samuel Joseph Hertzog; Julien Marius Ordan
A legacy of discovery and innovation at CERN
Located in Geneva, Switzerland, CERN is the world’s largest particle physics laboratory, renowned for its groundbreaking discoveries and cutting-edge experiments.
Rochester researchers have a long history of working at CERN as part of the CMS collaboration, including playing a key role in the 2012 discovery of the Higgs boson, an elementary particle that helps explain the origin of mass in the universe.
The collaboration’s work involves collecting and analyzing data gathered by the compact muon solenoid detector at CERN’s Large Hadron Collider (LHC), the world’s largest and most powerful particle accelerator. The LHC consists of a 17-mile ring of superconducting magnets and accelerating structures built underground and spanning the border between Switzerland and France.
The main goal of the LHC is to study the fundamental building blocks of matter and the forces that govern them. It does this by accelerating beams of protons or ions to near the speed of light and causing them to collide at extremely high energies. These collisions recreate conditions similar to those that existed a few fractions of a second after the Big Bang, allowing scientists to study the behavior of particles in extreme conditions.
Untangling the unified forces
In the 19th century, scientists discovered that the different forces of electricity and magnetism were linked: a changing electric field produces a magnetic field and vice versa. This discovery forms the basis of electromagnetism, which describes light as a wave and explains many optical phenomena, while describing how electric and magnetic fields interact.
Building on this understanding, physicists in the 1960s discovered that electromagnetism is related to another force, the weak force. This force operates in the nuclei of atoms and is responsible for processes such as radioactive decay and powering solar energy production. This revelation led to the development of electroweak theory, which posits that electromagnetism and the weak force are actually low-energy manifestations of a unified force called the unified electroweak interaction. Key discoveries, such as the Higgs boson, confirmed this concept.
Progress in electroweak interaction
The CMS collaboration recently made one of the most precise measurements of this theory to date, analyzing billions of proton-proton collisions at CERN’s LHC. Their goal was to measure the weak mixing angle, a parameter describing how electromagnetism and the weak force mix to create particles.
Previous measurements of the electroweak mixing angle have sparked debate in the scientific community. However, the latest findings closely match predictions from the Standard Model of particle physics. Rochester graduate student Rhys Taus and postdoctoral research associate Aleko Khukhunaishvili implemented new techniques to minimize the systematic uncertainties inherent in this measurement, improving its accuracy.
Understanding the low mixing angle sheds light on how different forces in the universe work together at the smallest scales, deepening understanding of the fundamental nature of matter and energy.
“The Rochester team has been developing innovative techniques and measuring these electroweak parameters since 2010, and then implementing them at the Large Hadron Collider,” Bodek says. “These new techniques have heralded a new era of testing the accuracy of Standard Model predictions.”