74-634: The Snowmass Process is a particle physics community planning exercise sponsored by the Division of Particles and Fields of the American Physical Society . During this process, scientists develop a collective vision for the next seven to ten years for particle physics research in the US. Original planning meetings were held beginning in 1982 in Snowmass, Colorado , but that has not been
148-487: A Hilbert space , which is also treated in quantum field theory . Following the convention of particle physicists, the term elementary particles is applied to those particles that are, according to current understanding, presumed to be indivisible and not composed of other particles. Ordinary matter is made from first- generation quarks ( up , down ) and leptons ( electron , electron neutrino ). Collectively, quarks and leptons are called fermions , because they have
222-402: A microsecond . They occur after collisions between particles made of quarks, such as fast-moving protons and neutrons in cosmic rays . Mesons are also produced in cyclotrons or other particle accelerators . Particles have corresponding antiparticles with the same mass but with opposite electric charges . For example, the antiparticle of the electron is the positron . The electron has
296-502: A quantum spin of half-integers (−1/2, 1/2, 3/2, etc.). This causes the fermions to obey the Pauli exclusion principle , where no two particles may occupy the same quantum state . Quarks have fractional elementary electric charge (−1/3 or 2/3) and leptons have whole-numbered electric charge (0 or 1). Quarks also have color charge , which is labeled arbitrarily with no correlation to actual light color as red, green and blue. Because
370-1058: A " Theory of Everything ", or "TOE". There are also other areas of work in theoretical particle physics ranging from particle cosmology to loop quantum gravity . In principle, all physics (and practical applications developed therefrom) can be derived from the study of fundamental particles. In practice, even if "particle physics" is taken to mean only "high-energy atom smashers", many technologies have been developed during these pioneering investigations that later find wide uses in society. Particle accelerators are used to produce medical isotopes for research and treatment (for example, isotopes used in PET imaging ), or used directly in external beam radiotherapy . The development of superconductors has been pushed forward by their use in particle physics. The World Wide Web and touchscreen technology were initially developed at CERN . Additional applications are found in medicine, national security, industry, computing, science, and workforce development, illustrating
444-426: A 5σ understanding of the mass ordering were more hopeful in a head-to-head competition with Hyper-K, with DUNE beating Hyper-K by two years if the 2022 schedule does not slip. This is because Hyper-K has a shorter baseline than DUNE, and capability of determining the mass-ordering depends on distance the neutrinos travel. However, both DUNE and Hyper-K are predicted to be scooped on the mass ordering by combination of
518-403: A 635-foot-long particle decay pipe. The hill is integral to the "improved tritium management [that is] a major focus on the design of this new, higher beam power facility." Tritium produced by beamlines can enter the surface ground water, however rates at Fermilab are maintained at a level well below that allowed by regulations. In order to provide 1.2 MW of protons to LBNF, the second phase of
592-707: A US-only project called the Long Baseline Neutrino Experiment ( LBNE ); in around 2012–2014 a descope was considered with a near-surface detector to reduce cost. However, the Particle Physics Project Prioritization Panel (P5) concluded in its 2014 report that the research activity being pursued by LBNE "should be reformulated under the auspices of a new international collaboration, as an internationally coordinated and internationally funded program, with Fermilab as host". The LBNE collaboration
666-507: A de-scoped instrument. Cost over-runs and delays of DUNE are problematic due to stiff competition from a similar experiment in Japan, leaving physicists to question the value of DUNE results when they are obtained. Worries were expressed by physicists that issues with DUNE were "smoothed over, not smoothed out". Some physicists at Snowmass suggested that the DUNE project might be cancelled, comparing
740-452: A fourth generation of fermions does not exist. Bosons are the mediators or carriers of fundamental interactions, such as electromagnetism , the weak interaction , and the strong interaction . Electromagnetism is mediated by the photon , the quanta of light . The weak interaction is mediated by the W and Z bosons . The strong interaction is mediated by the gluon , which can link quarks together to form composite particles. Due to
814-601: A history of lower-than-requested congressional appropriations for the project, at the same November 2021 meeting, DOE presented a "conservative profile [for funding] that the Office of Science can support." In March, 2022, as part of the CD-1RR process, DOE announced that the project would be completed in two phases. The plan for phasing was announced during the Snowmass Process , an exercise periodically organized by
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#1732772144815888-749: A long and growing list of beneficial practical applications with contributions from particle physics. Major efforts to look for physics beyond the Standard Model include the Future Circular Collider proposed for CERN and the Particle Physics Project Prioritization Panel (P5) in the US that will update the 2014 P5 study that recommended the Deep Underground Neutrino Experiment , among other experiments. Deep Underground Neutrino Experiment The Deep Underground Neutrino Experiment ( DUNE )
962-430: A negative electric charge, the positron has a positive charge. These antiparticles can theoretically form a corresponding form of matter called antimatter . Some particles, such as the photon , are their own antiparticle. These elementary particles are excitations of the quantum fields that also govern their interactions. The dominant theory explaining these fundamental particles and fields, along with their dynamics,
1036-612: A new direction in CERN's neutrino's research and the experiments are referred to as part of the Neutrino Platform in the laboratory's research programme. The MicroBooNE experiment and ICARUS experiment detectors are a pair of 100-ton-scale LArTPCs in the Fermilab program that also act as R&D platforms for DUNE detector development. These experiments have provided important input, but are more than 20 times smaller than
1110-598: A result, during the Snowmass process, physicists argued for precision measurements at a Higgs factory constructed of an electron-positron collider. Many Higgs factories are proposed for outside of the US, including at the European center for particle physics, CERN , as well as in China, and so "a surprise at Snowmass 'was the grassroots support for a collider on US soil'" that grew out of a new US-developed technology called
1184-523: A straight line through the Earth, reaching about 30 kilometers (19 mi) underground near the mid-point, to arrive at the underground laboratory in Lead, South Dakota. To point the neutrinos toward the underground laboratory, the beam must be directed into the earth at a steep angle. LBNF construction will include a 58-foot-high hill made of compacted soil, connecting to a 680-foot-long tunnel that will contain
1258-435: A wide range of exotic particles . All particles and their interactions observed to date can be described almost entirely by the Standard Model. Dynamics of particles are also governed by quantum mechanics ; they exhibit wave–particle duality , displaying particle-like behaviour under certain experimental conditions and wave -like behaviour in others. In more technical terms, they are described by quantum state vectors in
1332-450: A £65M investment in DUNE and LBNF. By 2022, the international partners providing in-kind contributions also included CERN , Brazil, Switzerland and Poland and the total foreign contribution to the $ 3B project was $ 570M, or about 20%. In August 2024, scientists detected the first neutrinos using a DUNE prototype particle detector at the U.S. Department of Energy’s Fermi National Accelerator Laboratory . The original scope and cost for
1406-566: 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 (in Illinois ) will be sent over a distance of 1,300 kilometers (810 mi) with the goal of understanding the role of neutrinos in
1480-531: Is a 260 kton total volume detector under construction 295 km from the Japan Proton Accelerator Research Complex ( J-PARC ) neutrino source. Construction is estimated to be completed by 2027. The Japanese government has had strict cost controls and has not allowed the costs to Japan to extend beyond the original 2016 estimate of approximately $ 600M. The project has received about $ 150M in international contributions. Thus,
1554-425: Is a particle physics theory suggesting that systems with higher energy have a smaller number of dimensions. A third major effort in theoretical particle physics is string theory . String theorists attempt to construct a unified description of quantum mechanics and general relativity by building a theory based on small strings, and branes rather than particles. If the theory is successful, it may be considered
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#17327721448151628-406: Is based on state-of-the-art Liquid Argon Time Projection Chamber (LArTPC) technology. The far detector will consist of a total volume of 70-kilotons of liquid argon located deep underground, 1.5 kilometers (4,850 ft) under the surface. The current design divides the liquid argon between four LArTPC modules with a "fiducial volume" (the volume usable for physics analysis, which is smaller than
1702-554: Is called the Standard Model . The reconciliation of gravity to the current particle physics theory is not solved; many theories have addressed this problem, such as loop quantum gravity , string theory and supersymmetry theory . Practical particle physics is the study of these particles in radioactive processes and in particle accelerators such as the Large Hadron Collider . Theoretical particle physics
1776-532: Is explained by the Standard Model , which gained widespread acceptance in the mid-1970s after experimental confirmation of the existence of quarks . It describes the strong , weak , and electromagnetic fundamental interactions , using mediating gauge bosons . The species of gauge bosons are eight gluons , W , W and Z bosons , and the photon . The Standard Model also contains 24 fundamental fermions (12 particles and their associated anti-particles), which are
1850-595: Is in model building where model builders develop ideas for what physics may lie beyond the Standard Model (at higher energies or smaller distances). This work is often motivated by the hierarchy problem and is constrained by existing experimental data. It may involve work on supersymmetry , alternatives to the Higgs mechanism , extra spatial dimensions (such as the Randall–Sundrum models ), Preon theory, combinations of these, or other ideas. Vanishing-dimensions theory
1924-471: Is the study of these particles in the context of cosmology and quantum theory . The two are closely interrelated: the Higgs boson was postulated by theoretical particle physicists and its presence confirmed by practical experiments. The idea that all matter is fundamentally composed of elementary particles dates from at least the 6th century BC. In the 19th century, John Dalton , through his work on stoichiometry , concluded that each element of nature
1998-600: Is used to extract the parameters of the Standard Model with less uncertainty. This work probes the limits of the Standard Model and therefore expands scientific understanding of nature's building blocks. Those efforts are made challenging by the difficulty of calculating high precision quantities in quantum chromodynamics . Some theorists working in this area use the tools of perturbative quantum field theory and effective field theory , referring to themselves as phenomenologists . Others make use of lattice field theory and call themselves lattice theorists . Another major effort
2072-465: The Hyper-Kamiokande experiment in Japan, scheduled to begin data-taking in 2027. The DUNE project, overseen by Fermilab , has suffered delays to its schedule and growth of cost from less than $ 2B to more than $ 3B, leading to articles in the journals Science and Scientific American that described the project as "troubled." In 2022, the DUNE experiment had a neutrino-beam start-date in
2146-614: The JUNO experiment in China and a set of atmospheric neutrino experiments that exist or are now under construction. Fermilab Director Merminga was confronted about the potential for DUNE to be scooped by the competition in a presentation to the House Science Committee in June 2022. In response, Merminga claimed that the projects are complementary, with DUNE providing more precise reconstructions of neutrino interactions due to
2220-592: The Proton Improvement Project ("PIP II"), which will increase proton delivery from the Fermilab accelerator chain by 60%, must be completed. The cost of this Fermilab upgrade as of 2022 is $ 1.28B. Thus, the PIP II and DUNE Phase I combined costs exceed $ 4B. The PIP II project received approval to begin construction in April 2022 and is expected to be completed by 2028. The DUNE far detector design
2294-532: The Standard Model that forms the present basis of particle physics is complete up to the Planck scale (an energy level far beyond the ability of any conceivable experiment to probe) and particle physics "wheeze[s] to its end". However the 2012 the discovery of an expected particle, the Higgs Boson, has given the field hope of finding new physics through precision searches for unexpected Higgs interactions. As
Snowmass Process - Misplaced Pages Continue
2368-544: The atomic nuclei are baryons – the neutron is composed of two down quarks and one up quark, and the proton is composed of two up quarks and one down quark. A baryon is composed of three quarks, and a meson is composed of two quarks (one normal, one anti). Baryons and mesons are collectively called hadrons . Quarks inside hadrons are governed by the strong interaction, thus are subjected to quantum chromodynamics (color charges). The bounded quarks must have their color charge to be neutral, or "white" for analogy with mixing
2442-401: The weak interaction , and the strong interaction . Quarks cannot exist on their own but form hadrons . Hadrons that contain an odd number of quarks are called baryons and those that contain an even number are called mesons . Two baryons, the proton and the neutron , make up most of the mass of ordinary matter. Mesons are unstable and the longest-lived last for only a few hundredths of
2516-425: The "cool copper collider". An alternative if the world-wide competition for an electron-positron machine is too stiff would be to invest in a Muon collider that could act as a Higgs factory with an approach that is unique worldwide. Muon colliders were discussed at the 2013 Snowmass, but shelved due to insufficiently advanced technology. However, at the 2022 final Snowmass meeting there was an "enthusiastic revival" of
2590-457: The DUNE modules. MicroBooNE is the longest continuously running LArTPC detector, having taken data from 2015 to 2021—considerably shorter than the time-period of 20 years expected for DUNE. The DUNE near detector will be located on the Fermilab site, downstream of LBNF, about 600 meters from where the neutrinos are produced. The DUNE near detector comprises several subdetectors that will sit side by side. One of these (SAND) will be installed along
2664-724: The Division of Particles and Fields (DPF) of the American Physical Society to plan the future of particle physics. Nominally, Phase I would consist of the first two far detector modules, a subset of the near detector system, and the 1.2 MW beamline, to be completed by 2032 for the estimated $ 3.1B cost. The CD-1RR process was completed on February 16, 2023, with an estimated cost for the project of $ 3.3B and an upper allowed cost range of $ 3.7B. To meet this cost, detector module 2 will be only 40% filled with liquid argon at project completion, and therefore not immediately usable for physics. The $ 3.3B cost does not include
2738-596: The LBNE project was established in step-1 of the Department of Energy "Critical Decision" process. Approval of CD-1 occurred in December 2012 The approved design significantly scaled back the physicist's request, which cost $ 1.7B. The CD-1 approval was for a budget of $ 850M, the proposed near detector was not included and the far detectors were recommended to be located on the surface rather than underground. Following
2812-605: The Open Cut due to DUNE construction led to complaints from businesses, homeowners, and users of a nearby park. Complaints continued through spring 2022 without adequate response from Fermilab management, resulting in the South Dakota Science and Technology Authority shutting down excavation on March 31, 2022. An investigation ensued in which the Fermilab management team admitted to failures in protocols, and instigated new measures to prevent black dust from leaving
2886-548: The P5 recommendation for a more robust project scope that included underground detectors, the project received a first CD-1 reaffirmation ("CD-1R") under the name LBNF/DUNE in November 2015. The scope of LBNF/DUNE was published in the 2016 Conceptual Design Report called for the first two far detector modules to be completed in 2024, the beam to be operational in 2026, and the four modules to be operational in 2027. The DOE estimated
2960-408: The Standard Model during the 1970s, physicists clarified the origin of the particle zoo. The large number of particles was explained as combinations of a (relatively) small number of more fundamental particles and framed in the context of quantum field theories . This reclassification marked the beginning of modern particle physics. The current state of the classification of all elementary particles
3034-571: The aforementioned color confinement, gluons are never observed independently. The Higgs boson gives mass to the W and Z bosons via the Higgs mechanism – the gluon and photon are expected to be massless . All bosons have an integer quantum spin (0 and 1) and can have the same quantum state . Most aforementioned particles have corresponding antiparticles , which compose antimatter . Normal particles have positive lepton or baryon number , and antiparticles have these numbers negative. Most properties of corresponding antiparticles and particles are
Snowmass Process - Misplaced Pages Continue
3108-402: The approximately $ 1B price of the PIP II upgrade that is required for DUNE, nor $ 660M promised as of February, 2023, from international partners for DUNE. Including these funds, the total cost for Phase I of LBNF/DUNE at the end of the CD-1RR review process was close to $ 5B. Phase II would complete the full scope by adding the additional two far modules, completing the suite of subdetectors at
3182-399: The concept. The possibility of establishing any major new project in the US in the 2023-2033 decade, including a Higgs Factory, is limited due to the rising costs and multi-year delays of existing projects. In particular, at Snowmass, physicists expressed deep concern about the Deep Underground Neutrino Experiment (DUNE) project, which has risen from a base cost of $ 1.3B in 2015 to $ 3.1B for
3256-597: The constituents of all matter . Finally, the Standard Model also predicted the existence of a type of boson known as the Higgs boson . On 4 July 2012, physicists with the Large Hadron Collider at CERN announced they had found a new particle that behaves similarly to what is expected from the Higgs boson. The Standard Model, as currently formulated, has 61 elementary particles. Those elementary particles can combine to form composite particles, accounting for
3330-529: The cost of Hyper-K is approximately equal to the CD-1 approved cost for LBNE (the DUNE predecessor) in the early 2010's. In comparison the DUNE Phase I detector is much smaller---only 17 kt---and the distance from the Fermilab neutrino source to the detector is longer---1300 km. This leads to a much lower expected rate of interactions in DUNE than Hyper-K. Also, the timescale of Hyper-K remains on-track, and so
3404-607: The decisions of the 2014 Particle Physics Project Prioritization Panel . A newsworthy outcome of the 2021 Snowmass Process was the announcement that the Deep Underground Neutrino Experiment would be pursued in two distinct phases. The outcomes of the Snowmass 2021 process, which extended into 2022, were determined at a final meeting held in July 2022 in Seattle, Washington that had 743 in-person attendees and 654 virtual participants. Snowmass outcomes were covered in detailed articles by
3478-498: The detector can be expected to start taking data 4 to 5 years earlier than the present projections for DUNE. The premiere result from DUNE on CP violation is predicted to lag the result from Hyper-K by 5 years. The final report of the Snowmass 2021 Topical Group Report on Three-Flavor Neutrino Oscillations released on June 15, 2022 estimated that a 5σ (hence discovery level) result on CP violation would be released from Hyper-K in 2034 and from DUNE in 2039. Estimations on reaching
3552-450: The development of nuclear weapons . Throughout the 1950s and 1960s, a bewildering variety of particles was found in collisions of particles from beams of increasingly high energy. It was referred to informally as the " particle zoo ". Important discoveries such as the CP violation by James Cronin and Val Fitch brought new questions to matter-antimatter imbalance . After the formulation of
3626-529: The early-2030's, and the project is now phased. The beamline for DUNE is called the "Long Baseline Neutrino Facility" (LBNF). The final design calls for a 2.4 MW proton beam from the Main Injector accelerator to be targeted in the LBNF beamline to produce pions and kaons that are magnetically focused into a decay pipe via a magnetic horn where they decay to neutrinos . The neutrinos will travel in
3700-470: The far detector modules. Excavation of the DUNE far detector cavities began on July 21, 2017. Seven years later, on August 15, 2024, the completion of the caverns was announced. Delays in completion arose from both the complexity of the project underground and from issues with dust release at the surface. Rock removed from underground was deposited in the Open Cut in the center of the city of Lead, South Dakota . In June 2021, plumes of dust rising from
3774-478: The first experimental deviations from the Standard Model, since neutrinos do not have mass in the Standard Model. Modern particle physics research is focused on subatomic particles , including atomic constituents, such as electrons , protons , and neutrons (protons and neutrons are composite particles called baryons , made of quarks ), that are produced by radioactive and scattering processes; such particles are photons , neutrinos , and muons , as well as
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#17327721448153848-538: The gravitational interaction, but it has not been detected or completely reconciled with current theories. Many other hypothetical particles have been proposed to address the limitations of the Standard Model. Notably, supersymmetric particles aim to solve the hierarchy problem , axions address the strong CP problem , and various other particles are proposed to explain the origins of dark matter and dark energy . The world's major particle physics laboratories are: Theoretical particle physics attempts to develop
3922-400: The highest energy accelerator on Earth—a disappointment stated by many physicists throughout the Snowmass process, and reflecting a view that has also been expressed outside of the Snowmass meetings. Although LHC will continue to run with modest upgrades, this lack of discovery leaves no clear focus for the next decade of high energy searches, and may also point to a "nightmare-scenario" where
3996-424: The hundreds of other species of particles that have been discovered since the 1960s. The Standard Model has been found to agree with almost all the experimental tests conducted to date. However, most particle physicists believe that it is an incomplete description of nature and that a more fundamental theory awaits discovery (See Theory of Everything ). In recent years, measurements of neutrino mass have provided
4070-433: The interactions between the quarks store energy which can convert to other particles when the quarks are far apart enough, quarks cannot be observed independently. This is called color confinement . There are three known generations of quarks (up and down, strange and charm , top and bottom ) and leptons (electron and its neutrino, muon and its neutrino , tau and its neutrino ), with strong indirect evidence that
4144-491: The liquid argon technology than can be achieved in the water-based Hyper-K water detector. However, Merminga did not explain why more precise reconstruction is required given that the water detectors can reach the same physics goals. The Sanford Underground Research Facility makes use of, and is extending, the facilities of the Homestake Mine (South Dakota) , which ceased operations at the end of 2001, to accommodate
4218-763: The location since 2005. More recent locations of the Snowmass Process include the University of Minnesota (2013) and the University of Washington (2021), which was delayed until July 2022, due to COVID . The modern Snowmass Process consists of a series of small meetings, which culminate in a community-wide meeting. The Snowmass Process solicits reports on progress and plans within "frontiers". Snowmass 2021 identified ten frontiers: "energy; neutrino physics; rare processes and precision measurements; cosmic; theory; accelerator; instrumentation; computation; underground facilities; and community engagement". Members of
4292-497: The models, theoretical framework, and mathematical tools to understand current experiments and make predictions for future experiments (see also theoretical physics ). There are several major interrelated efforts being made in theoretical particle physics today. One important branch attempts to better understand the Standard Model and its tests. Theorists make quantitative predictions of observables at collider and astronomical experiments, which along with experimental measurements
4366-424: The near site and upgrading the beam power to 2.4 MW. Phase II represents cost beyond the $ 3.1B estimate for Phase I and has been estimated to be at least an additional $ 900M. Physicists have expressed concern that the two phase plan may lead to DUNE falling far behind its primary competition, the Hyper-Kamiokande experiment, and that Phase II may not ever be constructed. Project Manager Chris Mossey reported on
4440-411: The neutrino beam axis. The others (NDLAr and NDGar) are movable and can be shifted in the direction perpendicular to the beam to detect neutrinos at different production angles. The primary purpose is to monitor and characterize the beam as the neutrinos are created in the LBNF line, so as to make accurate predictions for interaction rates at the DUNE far detector. The project was originally started as
4514-567: The ominous cost-growth to the Superconducting Super Collider (SSC) that was cancelled when the cost tripled. The whitepapers from the Snowmass process provide input to the 2023 P5 study. The 2023 P5 committee was announced in December 2022. Particle physics Particle physics or high-energy physics is the study of fundamental particles and forces that constitute matter and radiation . The field also studies combinations of elementary particles up to
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#17327721448154588-585: The particle physics community submit Letters of interest and provide input to contributed whitepapers . The frontiers use these whitepapers to provide web-based reports based on the material that they receive. The final output of the Snowmass Process is a Snowmass Summary for the Public, a Snowmass Summary Report, and the Snowmass Book. The Snowmass Process outcomes of 2013 were used to inform
4662-483: The photon or gluon, have no antiparticles. Quarks and gluons additionally have color charges, which influences the strong interaction. Quark's color charges are called red, green and blue (though the particle itself have no physical color), and in antiquarks are called antired, antigreen and antiblue. The gluon can have eight color charges , which are the result of quarks' interactions to form composite particles (gauge symmetry SU(3) ). The neutrons and protons in
4736-426: The primary colors . More exotic hadrons can have other types, arrangement or number of quarks ( tetraquark , pentaquark ). An atom is made from protons, neutrons and electrons. By modifying the particles inside a normal atom, exotic atoms can be formed. A simple example would be the hydrogen-4.1 , which has one of its electrons replaced with a muon. The graviton is a hypothetical particle that can mediate
4810-647: The project's cost to be between $ 1.26 billion to $ 1.86 billion. At the time of CD-1R, the DOE required that if the projected baseline cost rise to exceed $ 2.79 billion, or 50% above the range’s upper bound, then CD-1R must be revisited---a situation that was already being realized by 2020. In November 2021, Department of Energy (DOE) Office of Science officials reported to the High Energy Physics Advisory Panel that although DUNE had secured $ 570M in international funding at that time,
4884-444: The same, with a few gets reversed; the electron's antiparticle, positron, has an opposite charge. To differentiate between antiparticles and particles, a plus or negative sign is added in superscript . For example, the electron and the positron are denoted e and e . When a particle and an antiparticle interact with each other, they are annihilated and convert to other particles. Some particles, such as
4958-622: The scale of protons and neutrons , while the study of combination of protons and neutrons is called nuclear physics . The fundamental particles in the universe are classified in the Standard Model as fermions (matter particles) and bosons (force-carrying particles). There are three generations of fermions, although ordinary matter is made only from the first fermion generation. The first generation consists of up and down quarks which form protons and neutrons , and electrons and electron neutrinos . The three fundamental interactions known to be mediated by bosons are electromagnetism ,
5032-498: The scientific press. The title of the Scientific American article, "Physicists Struggle to Unite Around Future Plans", summed up the problem of convergence of opinion. The articles report that two major problems stymied the field: lack of observation of new particles and rocketing costs of ongoing projects. No unexpected particles were observed in the first 15 years of data-taking at the Large Hadron Collider (LHC),
5106-456: The source of the rising costs to the 2023 Particle Physics Project Prioritization Panel at a meeting held at Fermilab in March 2023. He stated that the sources were: Apart from the project management issues identified above, one can also identify sociological issues that contributed to the rising costs: The primary competition to DUNE is the Hyper-Kamiokande (Hyper-K) experiment. Hyper-K
5180-477: The total cost of the project was at the point of triggering a CD-1R rereview, called CD-1RR. DOE reviews held in January and June 2021 concluded that even a descoped version of the project consisting of only two far detectors and a near detector would exceed the DOE upper allowed range of total project cost growth of $ 2.75B. The CD-1RR process was to establish an improved cost range and schedule by mid-2022. Due to
5254-573: The total volume to avoid interactions near detector edges) of 10 kilotons each. About 800,000 tons of rock will be excavated to create the caverns for the far detectors. Since LArTPCs are relatively new technology, extensive R&D and prototyping have been required. Prototype detectors are being constructed and tested at CERN . The first of the two prototypes, the single-phase ProtoDUNE (CERN experiment NP04 ), recorded its first particle tracks in September 2018. CERN's participation in DUNE marked
5328-445: The universe. More than 1,000 collaborators work on the project. The experiment is designed for a 20-year period of data collection. The primary science objectives of DUNE are In 2014 the Particle Physics Project Prioritization Panel (P5) ranked this as "the highest priority project in its timeframe" (recommendation 13). The importance of these goals has led to proposals for competing projects in other countries, particularly
5402-682: Was composed of a single, unique type of particle. The word atom , after the Greek word atomos meaning "indivisible", has since then denoted the smallest particle of a chemical element , but physicists later discovered that atoms are not, in fact, the fundamental particles of nature, but are conglomerates of even smaller particles, such as the electron . The early 20th century explorations of nuclear physics and quantum physics led to proofs of nuclear fission in 1939 by Lise Meitner (based on experiments by Otto Hahn ), and nuclear fusion by Hans Bethe in that same year; both discoveries also led to
5476-511: Was officially dissolved on January 30, 2015, shortly after the new collaboration recommended by P5 was formed on January 22, 2015. The new collaboration selected the name Deep Underground Neutrino Experiment (DUNE). In response to the P5 call for more international involvement, as of 2022, scientists from over 30 countries were involved in the construction of LBNF and DUNE. In 2017, the UK's Science and Technology Facilities Council (STFC) announced
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