First traces of particles observed in a prototype for an international experiment on neutrinos

The world's largest liquid argon neutrino detector has just recorded its first particle tracks, marking the beginning of a new chapter in the history of deep underground neutrino international experimentation. (DUNE).

The scientific mission of DUNE is dedicated to the discovery of the mysteries of neutrinos, the most abundant (and most mysterious) matter particles in the universe. Neutrinos are all around us, but we know very little about them. DUNE scientists believe that neutrinos can help answer one of the most pressing questions in physics: why do we live in a universe dominated by matter? In other words, why are we here?

The huge ProtoDUNE detector – the size of a three-story house and the shape of a gigantic cube – was built at CERN, the European particle physics laboratory, as the first of two prototypes of what will be a much larger detector for the DUNE project, hosted by the Fermilab National Laboratory of the US Department of Energy's US Accelerator. When the first DUNE detector modules will record data in 2026, they will each be 20 times larger than these prototypes.

This is the first time that CERN has invested in the development of infrastructure and detectors for a particle physics project in the United States.

It took two years to build the first ProtoDUNE detector and eight weeks to fill it with 800 tons of liquid argon, which must be kept at temperatures below -184 degrees Celsius (-300 degrees Fahrenheit). The detector records traces of particles in this argon, derived from both cosmic rays and a beam created in the CERN accelerator complex. Now that the first leads have been seen, scientists will be using the detector over the next few months to test the technology in depth.

"Just two years ago, we completed the new CERN building to house two prototypes of large-scale detectors that are the cornerstone of DUNE," said Marzio Nessi, responsible for the CERN neutrino platform. . "Now we have the first detector that takes nice data, and the second detector, which uses a different approach to liquid argon technology, will be online in a few months."

The first ProtoDUNE detector technology will be the same as that used for the first of the DUNE detection modules in the United States, which will be built 1.6 km underground at the Sanford underground research facility in South Dakota. . More than 1,000 scientists and engineers from 32 countries in five continents – Africa, Asia, Europe, North America and South America – work on the development, design and construction of DUNE detectors. The opening ceremony of the caverns that will house the experiment took place in July 2017.

"Seeing the first traces of particles is a major success for the entire DUNE collaboration," said Stefan Soldner-Rembold, co-spokesperson for DUNE at the University of Manchester, UK. "DUNE is the largest collaboration of scientists working on neutrino research in the world, with the intention of creating a cutting-edge experiment that could change the way we view the universe."

When the neutrinos enter the detectors and enter the argon nuclei, they produce charged particles. These particles leave traces of ionization in the liquid, as shown by sophisticated tracking systems capable of creating three-dimensional images of invisible subatomic processes. (An animation of the DUNE and ProtoDUNE detectors, as well as other DUNE videos, is available here.)

"CERN is proud of the success of the Neutrino platform and its enthusiasm for being a partner of DUNE, with institutions and universities from its Member States and beyond," said Fabiola Gianotti, Director General of CERN. "These early results from ProtoDUNE are a great example of what can be achieved when laboratories around the world collaborate.The research with DUNE is complementary to the LHC research and other experiments at CERN." Exceptional questions in particle physics today. "

DUNE will study not only neutrinos, but also their antimatter counterparts. Scientists will look for differences in behavior between neutrinos and antineutrinos, which could give us clues about the dominance of the visible universe by matter. DUNE will also seek to detect the neutrinos produced by the explosion of a star, which could reveal the formation of neutron stars and black holes, and will be interested in the question of whether the protons live forever or end up to deteriorate. The observation of the disintegration of protons would bring us closer to the realization of Einstein's dream of a grand unified theory.

"DUNE is the future of neutrino research," said Nigel Lockyer, director of Fermilab. "Fermilab is delighted to welcome an international experiment with such vast potential for new discoveries and to continue our long partnership with CERN on both the DUNE project and the Large Hadron Collider."

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To learn more about the deep underground neutrino experiment, the installation of long-range neutrinos that will house the experiment and the PIP-II particle accelerator project at Fermilab that will feed the Neutrino beam of experience, visit http: // www.final.gov /dune.

DUNE comprises 175 institutions from 32 countries: Armenia, Brazil, Bulgaria, Canada, Chile, China, Colombia, Czech Republic, Finland, France, Greece, India, Iran, Italy, Japan, Madagascar, Mexico, Netherlands, Paraguay, Peru , Poland, Portugal, Romania, Russia, South Korea, Spain, Sweden, Switzerland, Turkey, Ukraine, United Kingdom and United States. The DUNE interim design report provides a detailed description of the technologies that will be used for DUNE detectors. More information on dunescience.org.

CERN, the European Organization for Nuclear Research, is one of the world's leading particle physics laboratories. The Organization is located at the French-Swiss border and is headquartered in Geneva. Its Member States are: Austria, Belgium, Bulgaria, Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Israel, Italy, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Spain, Sweden, Switzerland and the United Kingdom. . Cyprus, Serbia and Slovenia are associated Member States prior to accession. India, Lithuania, Pakistan, Turkey and Ukraine are associate member states. The European Union, Japan, the Institute, the Russian Federation, UNESCO and the United States of America currently have observer status.

Fermilab is the first US national laboratory for particle physics and accelerator research. Scientific laboratory of the US Department of Energy, Fermilab is located near Chicago, Illinois and operated under contract by Fermi Research Alliance LLC, a partnership between the University of Chicago and the Universities Research Association, Inc. Visit the Fermilab website at http: // www.final.gov and follow us on Twitter at @Fermilab.

The Brookhaven National Laboratory is supported by the US Department of Energy's Office of Science. The Office of Science is the largest advocate for basic science research in the United States and is addressing some of the most pressing challenges of our time. For more information, please visit science.energy.gov.

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One of the ten national laboratories supervised and primarily funded by the US Department of Energy (DOE) Science Bureau, Brookhaven National Laboratory conducts research in the fields of physical, biomedical and environmental sciences, technologies energy and national security. Brookhaven Lab also builds and operates significant scientific facilities for academic, industrial, and government researchers. Brookhaven is operated and managed for the DOE Office of Science by Brookhaven Science Associates, a limited liability company founded by the Research Foundation for the State University of New York on behalf of Stony Brook University, the largest user a scientific and technological organization applied to nonprofit.

Brookhaven Laboratory Physicists Deliver Key Components for ProtoDUNE Detector

Learn more about the Brookhaven Lab and the deep underground neutrino experiment

Arnaud Marsollier, CERN Press Office, +41 22 767 41 01, [email protected]

Andre Salles, Fermilab Communications Office, 630-840-3351, [email protected]

Karen McNulty Walsh, Brookhaven Lab's Media and Communications Office, 631-344-8350, [email protected]

Peter Genzer, Brookhaven Lab Media and Communications Office, 631-344-3174, [email protected]