From SURF: “Unlocking the mysteries of neutrinos”

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Sanford Underground levels

Sanford Underground Research facility


Thanks to the uncredited writer(s) and illustrator(s) for this incredible article.

Thanks also to Constance Walter and Matt Kapust fpr all of their great writing and photography.

This ghostly particle could answer a lot of questions about the universe, including how the universe was formed and why we exist.


What do we know about neutrinos?
In the Standard Model of Particle Physics,

The Standard Model of elementary particles (more schematic depiction), with the three generations of matter, gauge bosons in the fourth column, and the Higgs boson in the fifth.

neutrinos belong in the lepton family, fermions that make up matter. They are very tiny, have mass, travel near the speed of light and pass right through matter, making them very difficult to detect. They’re also quite tricky. As they travel over long distances, they oscillate, changing types, or flavors, along the way. More than 60 years after they were first discovered, we still have so much to learn about these ghostlike particles.

What we want to learn
What is the mass of a neutrino? Why do neutrinos oscillate, or change flavors, as they travel? Is the neutrino it’s own antiparticle? What is the neutrino’s role in the universe? What can neutrinos tell us about supernova and newly formed neutron stars? Several neutrino experiments around the world hope to answer these questions and more, including the Majorana Demonstrator Project and the Deep Underground Neutrino Experiment (DUNE), both located at SURF.

U Washington Majorana Demonstrator Experiment at SURF

FNAL LBNF/DUNE from FNAL to SURF, Lead, South Dakota, USA

FNAL DUNE Argon tank at SURF

Surf-Dune/LBNF Caverns at Sanford

SURF building in Lead SD USA


What are neutrinos?
Neutrinos are among the most abundant and least understood of all particles that make up the universe. Because they have no charge, they interact only through the weak subatomic force and gravity. They pass right through matter—not even millions of miles of lead can stop them. These near massless particles were born soon after the birth of the universe and are constantly produced in nuclear power plants; particle accelerators; general atmospheric phenomena; and during the births, collisions and deaths of stars.

Types of neutrinos
Neutrinos change flavors as they travel through space, going from electrons to muons to taus—in no particular order.


The number of neutrinos that pass through you every second
We can’t feel them or see them, but they are all around us. Unravelling the mysteries of neutrinos could tell us why matter triumphed over antimatter—and why the universe exists.

A neutrino beam that is shot through the earth
By exploring neutrino oscillations, scientists with the Deep Underground Neutrino Experiment (DUNE) hope to revolutionize our understanding of the role these tiny particles play in the creation of the universe. Using the Long-Baseline Neutrino Facility (LBNF), they’ll shoot a beam of neutrinos from Fermilab in Batavia, Illinois, 800 miles through the earth to detectors deep underground at Sanford Lab in Lead, South Dakota. LBNF will provide the infrastructure at Fermilab and Sanford Lab to support the DUNE detectors. And should a core-collapse supernova occurs in the Milky Way, we just might be able to see inside a newly formed neutron star and, potentially, witness the birth of a black hole.

DUNE website

An experiment that looks for no neutrinos
When the universe first formed, it had equal parts of matter and antimatter. Somewhere along the line, matter triumphed and planets, stars, and, eventually, humans came into existence. Why did matter win? That’s one question researchers with the Majorana Demonstrator want to answer. They’re looking for a Majorana particle, a mysterious fermion that is its own antiparticle. Their search for a rare form of radioactive decay, called neutrinoless double-beta decay, could tell us why matter exists. If they find the answer to this perplexing question, it will require rewriting the Standard Model of Particles and Interactions, our basic understanding of the physical world.

Netrinoless Double-Beta Decay animation

See the full article here .

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About us.
The Sanford Underground Research Facility in Lead, South Dakota, advances our understanding of the universe by providing laboratory space deep underground, where sensitive physics experiments can be shielded from cosmic radiation. Researchers at the Sanford Lab explore some of the most challenging questions facing 21st century physics, such as the origin of matter, the nature of dark matter and the properties of neutrinos. The facility also hosts experiments in other disciplines—including geology, biology and engineering.

The Sanford Lab is located at the former Homestake gold mine, which was a physics landmark long before being converted into a dedicated science facility. Nuclear chemist Ray Davis earned a share of the Nobel Prize for Physics in 2002 for a solar neutrino experiment he installed 4,850 feet underground in the mine.

Homestake closed in 2003, but the company donated the property to South Dakota in 2006 for use as an underground laboratory. That same year, philanthropist T. Denny Sanford donated $70 million to the project. The South Dakota Legislature also created the South Dakota Science and Technology Authority to operate the lab. The state Legislature has committed more than $40 million in state funds to the project, and South Dakota also obtained a $10 million Community Development Block Grant to help rehabilitate the facility.

In 2007, after the National Science Foundation named Homestake as the preferred site for a proposed national Deep Underground Science and Engineering Laboratory (DUSEL), the South Dakota Science and Technology Authority (SDSTA) began reopening the former gold mine.

In December 2010, the National Science Board decided not to fund further design of DUSEL. However, in 2011 the Department of Energy, through the Lawrence Berkeley National Laboratory, agreed to support ongoing science operations at Sanford Lab, while investigating how to use the underground research facility for other longer-term experiments. The SDSTA, which owns Sanford Lab, continues to operate the facility under that agreement with Berkeley Lab.

The first two major physics experiments at the Sanford Lab are 4,850 feet underground in an area called the Davis Campus, named for the late Ray Davis. The Large Underground Xenon (LUX) experiment is housed in the same cavern excavated for Ray Davis’s experiment in the 1960s.
LUX/Dark matter experiment at SURFLUX/Dark matter experiment at SURF

In October 2013, after an initial run of 80 days, LUX was determined to be the most sensitive detector yet to search for dark matter—a mysterious, yet-to-be-detected substance thought to be the most prevalent matter in the universe. The Majorana Demonstrator experiment, also on the 4850 Level, is searching for a rare phenomenon called “neutrinoless double-beta decay” that could reveal whether subatomic particles called neutrinos can be their own antiparticle. Detection of neutrinoless double-beta decay could help determine why matter prevailed over antimatter. The Majorana Demonstrator experiment is adjacent to the original Davis cavern.

Another major experiment, the Long Baseline Neutrino Experiment (LBNE)—a collaboration with Fermi National Accelerator Laboratory (Fermilab) and Sanford Lab, is in the preliminary design stages. The project got a major boost last year when Congress approved and the president signed an Omnibus Appropriations bill that will fund LBNE operations through FY 2014. Called the “next frontier of particle physics,” LBNE will follow neutrinos as they travel 800 miles through the earth, from FermiLab in Batavia, Ill., to Sanford Lab.

Fermilab LBNE