A neutrino is an elementary particle that interacts via the weak interaction and gravity. The neutrino is so named because it is electrically neutral and because its rest mass is so small (-ino) that it was long thought to be zero. The rest mass of the neutrino is much smaller than that of the other known elementary particles. The weak force has a very short range,the gravitational interaction is extremely weak due to the very small mass of the neutrino,and neutrinos do not participate in the electromagnetic interaction or the strong interaction. Thus,neutrinos typically pass through normal matter unimpeded and undetected.
The Sudbury Neutrino Observatory (SNO) was a neutrino observatory located 2100 m underground in Vale's Creighton Mine in Sudbury,Ontario,Canada. The detector was designed to detect solar neutrinos through their interactions with a large tank of heavy water.
Super-Kamiokande is a neutrino observatory located under Mount Ikeno near the city of Hida,Gifu Prefecture,Japan. It is operated by the Institute for Cosmic Ray Research,University of Tokyo with the help of an international team. It is located 1,000 m (3,300 ft) underground in the Mozumi Mine in Hida's Kamioka area. The observatory was designed to detect high-energy neutrinos,to search for proton decay,study solar and atmospheric neutrinos,and keep watch for supernovae in the Milky Way Galaxy.
Masatoshi Koshiba was a Japanese physicist and one of the founders of neutrino astronomy. His work with the neutrino detectors Kamiokande and Super-Kamiokande was instrumental in detecting solar neutrinos,providing experimental evidence for the solar neutrino problem.
The Collider Detector at Fermilab (CDF) experimental collaboration studies high energy particle collisions from the Tevatron,the world's former highest-energy particle accelerator. The goal is to discover the identity and properties of the particles that make up the universe and to understand the forces and interactions between those particles.
Main injector neutrino oscillation search (MINOS) was a particle physics experiment designed to study the phenomena of neutrino oscillations,first discovered by a Super-Kamiokande (Super-K) experiment in 1998. Neutrinos produced by the NuMI beamline at Fermilab near Chicago are observed at two detectors,one very close to where the beam is produced,and another much larger detector 735 km away in northern Minnesota.
T2K is a particle physics experiment studying the oscillations of the accelerator neutrinos. The experiment is conducted in Japan by the international cooperation of about 500 physicists and engineers with over 60 research institutions from several countries from Europe,Asia and North America and it is a recognized CERN experiment (RE13). T2K collected data within its first phase of operation from 2010 till 2021. The second phase of data taking is expected to start in 2023 and last until commencement of the successor of T2K –the Hyper-Kamiokande experiment in 2027.
Hyper-Kamiokande is a neutrino observatory and experiment under construction in Hida,Gifu and in Tokai,Ibaraki in Japan. It is conducted by the University of Tokyo and the High Energy Accelerator Research Organization (KEK),in collaboration with institutes from over 20 countries across six continents. As a successor of the Super-Kamiokande and T2K experiments,it is designed to search for proton decay and detect neutrinos from natural sources such as the Earth,the atmosphere,the Sun and the cosmos,as well as to study neutrino oscillations of the man-made accelerator neutrino beam. The beginning of data-taking is planned for 2027.
The Kamioka Observatory,Institute for Cosmic Ray Research,University of Tokyo is a neutrino and gravitational waves laboratory located underground in the Mozumi mine of the Kamioka Mining and Smelting Co. near the Kamioka section of the city of Hida in Gifu Prefecture,Japan. A set of groundbreaking neutrino experiments have taken place at the observatory over the past two decades. All of the experiments have been very large and have contributed substantially to the advancement of particle physics,in particular to the study of neutrino astronomy and neutrino oscillation.
The NOνA experiment is a particle physics experiment designed to detect neutrinos in Fermilab's NuMI beam. Intended to be the successor to MINOS,NOνA consists of two detectors,one at Fermilab,and one in northern Minnesota. Neutrinos from NuMI pass through 810 km of Earth to reach the far detector. NOνA's main goal is to observe the oscillation of muon neutrinos to electron neutrinos. The primary physics goals of NOvA are:
Yoji Totsuka was a Japanese physicist and Special University Professor,emeritus,University of Tokyo. A leader in the study of solar and atmospheric neutrinos,he was a scientist and director at Kamioka Observatory,Super-Kamiokande and the High Energy Physics Laboratory (KEK) in Japan.
The solar neutrino problem concerned a large discrepancy between the flux of solar neutrinos as predicted from the Sun's luminosity and as measured directly. The discrepancy was first observed in the mid-1960s and was resolved around 2002.
The K2K experiment was a neutrino experiment that ran from June 1999 to November 2004. It used muon neutrinos from a well-controlled and well-understood beam to verify the oscillations previously observed by Super-Kamiokande using atmospheric neutrinos. This was the first positive measurement of neutrino oscillations in which both the source and detector were fully under experimenters' control. Previous experiments relied on neutrinos from the Sun or from cosmic sources. The experiment found oscillation parameters which were consistent with those measured by Super-Kamiokande.
Measurements of neutrino speed have been conducted as tests of special relativity and for the determination of the mass of neutrinos. Astronomical searches investigate whether light and neutrinos emitted simultaneously from a distant source are arriving simultaneously on Earth. Terrestrial searches include time of flight measurements using synchronized clocks,and direct comparison of neutrino speed with the speed of other particles.
Takaaki Kajita is a Japanese physicist,known for neutrino experiments at the Kamioka Observatory –Kamiokande and its successor,Super-Kamiokande. In 2015,he was awarded the Nobel Prize in Physics jointly with Canadian physicist Arthur B. McDonald. On 1 October 2020,he became the president of the Science Council of Japan.
Eugene William Beier is an American physicist.
The diffuse supernova neutrino background(DSNB) is a theoretical population of neutrinos (and anti-neutrinos) cumulatively originating from all core-collapse supernovae events throughout the history of the universe. Though it has not yet been directly detected,the DSNB is theorized to be isotropic and consists of neutrinos with typical energies on the scale of 107 eV. Current detection efforts are limited by the influence of background noise in the search for DSNB neutrinos and are therefore limited to placing limits on the parameters of the DSNB,namely the neutrino flux. Restrictions on these parameters have gotten more strict in recent years,but many researchers are looking to make direct observations in the near future with next generation detectors. The DSNB is not to be confused with the cosmic neutrino background (CNB),which is comprised by relic neutrinos that were produced during the Big Bang and have much lower energies (10−4 to 10−6 eV).
Atsuto Suzuki is an experimental particle physicist known for his observations of neutrinos and anti-neutrinos.
KōichirōNishikawa was a Japanese elementary particle physicist,known for contributions to neutrino physics. He was professor emeritus of the KEK high-energy physics laboratory and Kyōto University.
Kevin T. Pitts is an American high energy particle physicist. In addition to his faculty appointment at the University of Illinois at Urbana–Champaign,in 2021 he was appointed chief research officer at Fermilab National Accelerator Laboratory. His research interests have included the CDF experiment and the Muon g-2 experiment at Fermilab.
