Nuclear Physics | Department of Energy Official websites use .gov .gov website belongs to an official government organization in the United States. Secure .gov websites use HTTPS lock ) or means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites. Nuclear Physics One of the enduring mysteries of the universe is the nature of matter—what are its basic constituents and how do they interact to form the elements and the properties we observe? The mission of the Nuclear Physics (NP) program is to solve this mystery by discovering, exploring, and understanding all forms of nuclear matter. Nuclear physicists seek to understand not just the familiar forms of matter we see around us, but also exotic forms such as those that existed in the first moments after the Big Bang and that exist today inside neutron stars. The aim is to understand why matter takes on the specific forms now observed in nature and how that knowledge can benefit society in the areas of commerce, medicine, and national security. The quest to understand the properties of different forms of nuclear matter requires long-term support for both theoretical and experimental research efforts. Theoretical approaches are based on calculations of the interactions of quarks and gluons, which form protons and neutrons, using today’s most advanced computers. Other theoretical research models the forces between protons and neutrons and seeks to understand and predict the structure of nuclear matter. Experiments in nuclear physics use large accelerators that collide particles up to nearly the speed of light to study the structure of nuclei, nuclear astrophysics and to produce short-lived forms of matter for investigation. Nuclear physicists also use low-energy, precision nuclear experiments, many enabled by new quantum sensors, to search for a deeper understanding of fundamental symmetries and nuclear interactions. Comparing experimental observations and theoretical predictions tests the limits of our understanding of nuclear matter and suggests new directions for experimental and theoretical research. Highly trained scientists who conceive, plan, execute, and interpret transformative experiments are at the heart of the NP program. NP supports these university and national laboratory scientists. We also support U.S. participation in select international collaborations and provide over 90 percent of the nuclear science research funding in the United States. The world-class scientific user facilities and associated instrumentation necessary to advance the U.S. nuclear science program are large and complex. NP supports four scientific user facilities: the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL); the Continuous Electron Beam Accelerator Facility (CEBAF) at Thomas Jefferson National Accelerator Facility (TJNAF); the Argonne Tandem Linac Accelerator System (ATLAS) at Argonne National Laboratory (ANL); and currently under construction the Facility for Rare Isotope Beams (FRIB) which will provide unprecedented opportunities to study the synthesis of the heavy elements in the cosmos. Each of these facilities has unique capabilities that advance NP’s scientific mission. NP Areas Research about Research NP Facilities about NP Facilities NP Science Highlights Physicists Propose a New Kind of Laser That Would Fire Neutrinos A potential tool could use Bose Einstein condensates to produce intense beams of neutrinos. about Physicists Propose a New Kind of Laser That Would Fire Neutrinos KATRIN Narrows Down the Range of Neutrinos’ Mass A direct search shows that neutrinos are at least a million times lighter than electrons. about KATRIN Narrows Down the Range of Neutrinos’ Mass When Neutron Stars Collide, Neutrinos Change Flavors Scientists have developed a simulation of the merger of two neutron stars that includes the oscillation of different neutrino flavors into one another. about When Neutron Stars Collide, Neutrinos Change Flavors New Clues on Twin Neutron Stars and the Extreme Physics Inside Scientists have new insights into factors that determine how twin neutron stars—stars with the same mass but different sizes and compositions—can coexist. about New Clues on Twin Neutron Stars and the Extreme Physics Inside Predictive Theory Revises Understanding of Alpha Processes During the Big Bang and in Massive Stars Theoretical calculations enable more accurate determination of reaction rates for modelling primordial lithium-6 abundance and massive stars’ lifecycle. about Predictive Theory Revises Understanding of Alpha Processes During the Big Bang and in Massive Stars Understanding How the Sun Shines: From Triton Decay to Proton-Proton Fusion Remarkably, the rate of proton-proton fusion in the sun is not precisely understood, but it can be better predicted using the process of triton decay. about Understanding How the Sun Shines: From Triton Decay to Proton-Proton Fusion New Technique for Understanding the Nature of Neutrinos Demonstrates an Important Technological Milestone Researchers imaged individual barium ions in dense xenon gas, offering a new path toward ultra-low-background searches for neutrinoless double beta decay. about New Technique for Understanding the Nature of Neutrinos Demonstrates an Important Technological Milestone Scientists Calculate Predictions for Electron-Ion Collider Measurements Calculations of charge distribution in mesons provide a benchmark for experimental measurements and validate widely used 'factorization' method. about Scientists Calculate Predictions for Electron-Ion Collider Measurements Rare Isotopes Shed Light on the Size of a Neutrino Wavepacket Precise measurement of beryllium-7 nuclear decay recoils directly probes the quantum properties of the neutrino for the first time. about Rare Isotopes Shed Light on the Size of a Neutrino Wavepacket Scientists Measure the Temperature Achieved in Heavy Ion Collisions by Looking at Broken Particles First precise measurement of a hard to detect bound charm quark pair state indicates it is not affected by the medium in high-energy proton-lead collisions. about Scientists Measure the Temperature Achieved in Heavy Ion Collisions by Looking at Broken Particles View More NP Program News Department of Energy Announces $5.8 Million for Research on Nuclear Data Benefitting Nuclear Science and Applications about Department of Energy Announces $5.8 Million for Research on Nuclear Data Benefitting Nuclear Science and Applications Department of Energy Announces $11.24 Million for Research on Nuclear Theory Topical Collaborations about Department of Energy Announces $11.24 Million for Research on Nuclear Theory Topical Collaborations Department of Energy Announces $8.6 Million for Research on Accelerator R&D for Nuclear Physics about Department of Energy Announces $8.6 Million for Research on Accelerator R&D for Nuclear Physics NP Research Resources NP Related Brochures and Videos about NP Related Brochures and Videos NP Reports about NP Reports NP Databases about NP Databases NP Funding Opportunities (FOAs) about NP Funding Opportunities (FOAs) Contact Information Nuclear Physics U.S. Department of Energy Germantown Building 1000 Independence Avenue., SW Washington, DC 20585 P: (301) 903 - 3613 F: (301) 903 - 3833 E: sc.np@science.doe.gov