Neutrinos are consistently surprising particles. They were first theorized in 1930 to explain a tiny loss of energy from other particle interactions and were first detected in 1956. Since their discovery they have revealed properties that were totally unexpected.
In the six decades since, scientists have discovered that there are three kinds (or flavors) of neutrino particles, that these particles have mass (in defiance of the Standard Model, the mathematical framework that describes the subatomic realm), and that they oscillate between the three types as they travel. Discoveries in neutrino physics have led to multiple Nobel prizes, and there are no signs that these particles will run out of secrets to reveal anytime soon.
DUNE will be the world’s most advanced and comprehensive experiment dedicated to understanding these particles. But its scope is even wider than that. In addition to providing the best data on neutrino interactions currently possible, DUNE will explore some of the most puzzling aspects of our universe with unprecedented precision and open the door to new insights into … well, everything.
DUNE has three primary science goals.
To search for the origin of matter
DUNE scientists will look at the differences in behavior between neutrinos and antineutrinos, aiming to find out whether neutrinos are the reason the universe is made of matter.
We exist because, 13.8 billion years ago, matter and antimatter were pitted against each other – and matter won.
Evidence suggests that a smidge more matter than antimatter developed in the first millionth of a second after the Big Bang. Matter and antimatter annihilate each other, so that only extra smidge survived. Instead of the nothingness that would have been the result of a perfect balance between matter and antimatter, we have a universe full of galaxies, planets and, on at least one planet, people.
Neutrinos could enlighten us about the mechanism that made matter the victor.
Neutrinos come in three flavors, called electron, muon and tau. As neutrinos travel, they change from one type into the other. That process is called oscillation.
Using the DUNE detectors, scientists will compare the rates of neutrino and antineutrino oscillation with greater precision than any other experiment on the planet. If they find a difference in oscillation rates, that could account for the imbalance between matter and antimatter that ultimately led to our existence.
To learn more about neutron stars and black holes
DUNE will look for the gigantic streams of neutrinos emitted by exploding stars to watch the formation of black holes and neutron stars in real time, to learn more about these mysterious objects in space.
Nature’s elements are forged in stars, and the heavier ones, like carbon, oxygen and iron, are created primarily in the final death throes of a star. The core of a star is a massive furnace, fusing lighter elements into heavier ones until it can fuse no further. Unable to withstand its own gravitational pull, the star then explodes into a supernova.
The exploding elements can become the seeds of future stars, and observing the formation of these stars clues us in to the evolution of our universe.
The very first particles loosed from these explosive events are neutrinos, which are expelled as a dense group at a fantastic rate. If DUNE scientists pick up the signal of neutrinos fleeing the supernova, they would be able to take advantage of a rare opportunity to study an exploding star. And they might even spot a black hole, the expected end product of some supernovae.
To shed light on the unification of nature’s forces
DUNE’s search for the signal of proton decay – a signal so rare it has never been seen, but has been theorized – will move scientists closer to realizing Einstein’s dream of a unified theory of matter and energy.
Scientists have discovered four forces that govern the universe: gravity, electromagnetism, the weak nuclear force and the strong nuclear force. But scientists have theorized that once upon a time, immediately after the Big Bang, only one force existed. And there are different theories about the strength of that one force (no, not The Force) and how it broke apart.
At that time, the various particles we know today may have been all alike and may have all responded to that one force in the same way. A fraction of a second later, the theory goes, that force broke apart into several, and now the various particle families respond to the different forces in different ways. Now there are very few windows into that original singular force, but the decay of the proton could be one of them.
Like other composite particles, protons should decay, but scientists have never seen this phenomenon. The chance of observing it is vanishingly small, but if it is spotted, it would narrow the field of possible grand unified theories and allow scientists to home in on a description of the theorized original single force. DUNE is designed to be sensitive to a number of types of proton decay and will provide an enormous volume of mass in which to detect it. If they do see this rare event, they may finally be on the path to a theory of unification.