Related Research Articles
A neutrino is a fermion that interacts only 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 excluding massless 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 strong interaction. Thus, neutrinos typically pass through normal matter unimpeded and undetected.
Sterile neutrinos are hypothetical particles that are believed to interact only via gravity and not via any of the other fundamental interactions of the Standard Model. The term sterile neutrino is used to distinguish them from the known, ordinary active neutrinos in the Standard Model, which carry an isospin charge of ±+1/ 2 and engage in the weak interaction. The term typically refers to neutrinos with right-handed chirality, which may be inserted into the Standard Model. Particles that possess the quantum numbers of sterile neutrinos and masses great enough such that they do not interfere with the current theory of Big Bang nucleosynthesis are often called neutral heavy leptons (NHLs) or heavy neutral leptons (HNLs).
MiniBooNE is a Cherenkov detector experiment at Fermilab designed to observe neutrino oscillations. A neutrino beam consisting primarily of muon neutrinos is directed at a detector filled with 800 tons of mineral oil and lined with 1,280 photomultiplier tubes. An excess of electron neutrino events in the detector would support the neutrino oscillation interpretation of the LSND result.
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 (T2K-II) is expected to start in 2023 and last until commencement of the successor of T2K – the Hyper-Kamiokande experiment in 2027.
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:
SciBar Booster Neutrino Experiment (SciBooNE), was a neutrino experiment located at the Fermi National Accelerator Laboratory (Fermilab) in the USA. It observed neutrinos of the Fermilab Booster Neutrino Beam (BNB) that are produced when protons from the Fermilab Booster-accelerator were made to hit a beryllium target; this led to the production of many short-lived particles that decayed into neutrinos. The SciBooNE detector was located some 100 meters downrange from the beryllium target, with a 50 meter decay-volume (where the particle decay into neutrinos) and absorber combined with 50 meters of solid ground between the target and the detector to absorb other particles than neutrinos. The neutrino-beam continued through SciBooNE and ground to the MiniBooNE-detector, located some 540 meters downrange from the target.
Main Injector Experiment for ν-A, or MINERνA, is a neutrino scattering experiment which uses the NuMI beamline at Fermilab. MINERνA seeks to measure low energy neutrino interactions both in support of neutrino oscillation experiments and also to study the strong dynamics of the nucleon and nucleus that affect these interactions.
Borexino is a deep underground particle physics experiment to study low energy (sub-MeV) solar neutrinos. The detector is the world's most radio-pure liquid scintillator calorimeter and is protected by 3,800 meters of water-equivalent depth. The scintillator is pseudocumene and PPO which is held in place by a thin nylon sphere. It is placed within a stainless steel sphere which holds the photomultiplier tubes (PMTs) used as signal detectors and is shielded by a water tank to protect it against external radiation. Outward pointing PMT's look for any outward facing light flashes to tag incoming cosmic muons that manage to penetrate the overburden of the mountain above. Neutrino energy can be determined through the number of photoelectrons measured in the PMT's. While the position can be determined by extrapolating the difference in arrival times of photons at PMT's throughout the chamber.
Lorentz-violating neutrino oscillation refers to the quantum phenomenon of neutrino oscillations described in a framework that allows the breakdown of Lorentz invariance. Today, neutrino oscillation or change of one type of neutrino into another is an experimentally verified fact; however, the details of the underlying theory responsible for these processes remain an open issue and an active field of study. The conventional model of neutrino oscillations assumes that neutrinos are massive, which provides a successful description of a wide variety of experiments; however, there are a few oscillation signals that cannot be accommodated within this model, which motivates the study of other descriptions. In a theory with Lorentz violation, neutrinos can oscillate with and without masses and many other novel effects described below appear. The generalization of the theory by incorporating Lorentz violation has shown to provide alternative scenarios to explain all the established experimental data through the construction of global models.
Double Chooz was a short-baseline neutrino oscillation experiment in Chooz, France. Its goal was to measure or set a limit on the θ13 mixing angle, a neutrino oscillation parameter responsible for changing electron neutrinos into other neutrinos. The experiment uses reactors of the Chooz Nuclear Power Plant as a neutrino source and measures the flux of neutrinos they receive. To accomplish this, Double Chooz has a set of two detectors situated 400 meters and 1050 meters from the reactors. Double Chooz was a successor to the Chooz experiment; one of its detectors occupies the same site as its predecessor. Until January 2015 all data has been collected using only the far detector. The near detector was completed in September 2014, after construction delays, and started taking data at the beginning of 2015. Both detectors stopped taking data in late December 2017.
Antonio Ereditato is an Italian physicist, currently associate researcher at Fermilab, Batavia, USA, and Emeritus professor at the University of Bern, Switzerland, where he has been Director of the Laboratory for High Energy Physics from 2006 to 2020. From 2021 to 2022 he has been Visiting Professor at the Yale University, USA. He carried out research activities in the field of experimental neutrino physics, of weak interactions and strong interactions with experiments conducted at CERN, in Japan, at Fermilab in United States and at the LNGS in Italy. Ereditato has accomplished several R&D studies on particle detectors: wire chambers, calorimeters, time projection chambers, nuclear emulsions, detectors for medical applications.
The Deep Underground Neutrino Experiment (DUNE) is a neutrino experiment under construction, with a near detector at Fermilab and a far detector at the Sanford Underground Research Facility that will observe neutrinos produced at Fermilab. An intense beam of trillions of neutrinos from the production facility at Fermilab will be sent over a distance of 1,300 kilometers (810 mi) with the goal of understanding the role of neutrinos in the universe. More than 1,000 collaborators work on the project. The experiment is designed for a 20-year period of data collection.
Modern searches for Lorentz violation are scientific studies that look for deviations from Lorentz invariance or symmetry, a set of fundamental frameworks that underpin modern science and fundamental physics in particular. These studies try to determine whether violations or exceptions might exist for well-known physical laws such as special relativity and CPT symmetry, as predicted by some variations of quantum gravity, string theory, and some alternatives to general relativity.
ICARUS is a physics experiment aimed at studying neutrinos. It was located at the Laboratori Nazionali del Gran Sasso (LNGS) where it started operations in 2010. After completion of its operations there, it was refurbished at CERN for re-use at Fermilab, in the same neutrino beam as the MiniBooNE, MicroBooNE and Short Baseline Near Detector (SBND) experiments. The ICARUS detector was then taken apart for transport and reassembled at Fermilab, where data collection is expected to begin in fall 2021.
The Accelerator Neutrino Neutron Interaction Experiment (ANNIE) is a proposed water Cherenkov detector experiment designed to examine the nature of neutrino interactions. This experiment will study phenomena like proton decay, and neutrino oscillations, by analyzing neutrino interactions in gadolinium-loaded water and measuring their neutron yield. Neutron Tagging plays an important role in background rejection from atmospheric neutrinos. By implementing early prototypes of LAPPDs, high precision timing is possible. The suggested location for ANNIE is the SciBooNE hall on the Booster Neutrino Beam associated with the MiniBooNE experiment. The neutrino beam originates in Fermilab where The Booster delivers 8 GeV protons to a beryllium target producing secondary pions and kaons. These secondary mesons decay to produce a neutrino beam with an average energy of around 800 MeV. ANNIE will begin installation in the summer of 2015. Phase I of ANNIE, mapping the neutron background, completed in 2017. The detector is being upgraded for full science operation which is expected to begin late 2018.
MicroBooNE is a liquid argon time projection chamber (LArTPC) at Fermilab in Batavia, Illinois. It is located in the Booster Neutrino Beam (BNB) beamline where neutrinos are produced by colliding protons from Fermilab's booster-accelerator on a beryllium target; this produces many short-lived particles that decay into neutrinos. The neutrinos pass through solid ground, through another experiment called ANNIE, then solid ground, then through the Short Baseline Near Detector, then ground again before it arrives at the MicroBooNE detector 470 meters downrange from the target. After MicroBooNE the neutrinos continue to the MiniBooNE detector and to the ICARUS detector. MicroBooNE is also exposed to the neutrino beam from the Main Injector (NuMI) which enter the detector at a different angle.
The STEREO experiment investigates the possible oscillation of neutrinos from a nuclear reactor into light so-called sterile neutrinos. It is located at the Institut Laue–Langevin (ILL) in Grenoble, France. The experiment started operating and taking data in November 2016.
Bonnie T. Fleming is an experimental particle physicist who has held leadership roles in several physics experiments and at Fermilab. Since 2022, she has been Fermilab's chief research officer and deputy director for science and technology. She has also served on the faculty of Yale University and the University of Chicago. Fleming is an expert in neutrino physics and liquid argon time projection chamber detector technology.
Geralyn P. (Sam) Zeller is an American neutrino physicist at Fermilab. At Fermilab, she is a participant in the MiniBooNE experiment, co-spokesperson for the MicroBooNE experiment, and deputy head of the Neutrino Division.
References
- ↑ S. Dodelson; A. Melchiorri; A. Slosar (2006). "Is cosmology compatible with sterile neutrinos?". Physical Review Letters . 97: 04301. arXiv: astro-ph/0511500 . Bibcode:2006PhRvL..97d1301D. doi:10.1103/PhysRevLett.97.041301.
