Doe Science news source
The DOE Science News Source is a Newswise initiative to promote research news from the Office of Science of the DOE to the public and news media.
  • 2017-11-20 15:55:16
  • Article ID: 685530

How the Earth Stops High-Energy Neutrinos in Their Tracks

Efforts by Berkeley Lab scientists are key in new study analyzing data from Antarctic experiment

  • Credit: IceCube Collaboration

    The IceCube Lab in March 2017, with the South Pole station in the background.

  • Credit: IceCube Collaboration

    In this study, researchers measured the flux of muon neutrinos as a function of their energy and their incoming direction. Neutrinos with higher energies and with incoming directions closer to the North Pole are more likely to interact with matter on their way through Earth.

**** EMBARGOED: scheduled for Advance Online Publication (AOP) on Nature at 1800 London time / 1300 US Eastern Time on 22 November 2017 ****

Neutrinos are abundant subatomic particles that are famous for passing through anything and everything, only very rarely interacting with matter. About 100 trillion neutrinos pass through your body every second.

Now, scientists have demonstrated that the Earth stops energetic neutrinos—they do not go through everything. These high-energy neutrino interactions were seen by the IceCube detector, an array of 5,160 basketball-sized optical sensors deeply encased within a cubic kilometer of very clear Antarctic ice near the South Pole.

IceCube’s sensors do not directly observe neutrinos, but instead measure flashes of blue light, known as Cherenkov radiation, emitted by muons and other fast-moving charged particles, which are created when neutrinos interact with the ice, and by the charged particles produced when the muons interact as they move through the ice. By measuring the light patterns from these interactions in or near the detector array, IceCube can estimate the neutrinos’ directions and energies.

The study, published in the Nov. 22 issue of the journal Nature, was led by researchers at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) and UC Berkeley.

Spencer Klein, who leads Berkeley Lab’s IceCube research team, commented “This analysis is important because it shows that IceCube can make real contributions to particle and nuclear physics, at energies above the reach of current accelerators.”

“You create ‘pretend’ muons that simulate the response of the sensors,” Miarecki said. “You have to simulate their behavior, there has to be an ice model to simulate the ice’s behavior, you also have to have cosmic ray simulations, and you have to simulate the Earth using equations. Then you have to predict, probability-wise, how often a particular muon would come through the Earth.”

The study’s results are based on one year of data from about 10,800 neutrino-related interactions, stemming from a natural supply of very energetic neutrinos from space that go through a thick and dense absorber: the Earth. The energy of the neutrinos was critical to the study, as higher energy neutrinos are more likely to interact with matter and be absorbed by the Earth.

Scientists found that there were fewer energetic neutrinos making it all the way through the Earth to the IceCube detector than from less obstructed paths, such as those coming in at near-horizontal trajectories. The probability of neutrinos being absorbed by the Earth was consistent with expectations from the Standard Model of particle physics, which scientists use to explain the fundamental forces and particles in the universe. This probability—that neutrinos of a given energy will interact with matter—is what physicists refer to as a “cross section.”

“Understanding how neutrinos interact is key to the operation of IceCube,” explained Francis Halzen, principal investigator for the IceCube Neutrino Observatory and a University of Wisconsin–Madison professor of physics. Precision measurements at the HERA accelerator in Hamburg, Germany, allow us to compute the neutrino cross section with great accuracy within the Standard Model—which would apply to IceCube neutrinos of much higher energies if the Standard Model is valid at these energies. “We were of course hoping for some new physics to appear, but we unfortunately find that the Standard Model, as usual, withstands the test,” adds Halzen.

James Whitmore, program director in the National Science Foundation’s physics division, said, “IceCube was built to both explore the frontiers of physics and, in doing so, possibly challenge existing perceptions of the nature of universe. This new finding and others yet to come are in that spirit of scientific discovery.”

This study provides the first cross-section measurements for a neutrino energy range that is up to 1,000 times higher than previous measurements at particle accelerators. Most of the neutrinos selected for this study were more than a million times more energetic than the neutrinos produced by more familiar sources, like the sun or nuclear power plants. Researchers took care to ensure that the measurements were not distorted by detector problems or other uncertainties.

“Neutrinos have quite a well-earned reputation of surprising us with their behavior,” said Darren Grant, spokesperson for the IceCube Collaboration and a professor of physics at the University of Alberta in Canada. “It is incredibly exciting to see this first measurement and the potential it holds for future precision tests.”

In addition to providing the first measurement of the Earth’s absorption of neutrinos, the analysis shows that IceCube’s scientific reach is extending beyond its core focus on particle physics discoveries and the emerging field of neutrino astronomy into the fields of planetary science and nuclear physics. This analysis will also interest geophysicists who would like to use neutrinos to image the Earth’s interior, although this will require more data than was used in the current study.

The neutrinos used in this analysis were mostly produced when hydrogen or heavier nuclei from high-energy cosmic rays, created outside the solar system, interacted with nitrogen or oxygen nuclei in the Earth’s atmosphere. This creates a cascade of particles, including several types of subatomic particles that decay, producing neutrinos. These particles rain down on the Earth’s surface from all directions.

The analysis also included a small number of astrophysical neutrinos, which are produced outside of the Earth’s atmosphere, from cosmic accelerators unidentified to date, perhaps associated with supermassive black holes.

The neutrino-interaction events that were selected for the study have energies of at least one trillion electron volts, or a teraelectronvolt (TeV), roughly the kinetic energy of a flying mosquito. At this energy, the Earth’s absorption of neutrinos is relatively small, and the lowest energy neutrinos in the study largely served as an absorption-free baseline. The analysis was sensitive to absorption in the energy range from 6.3 TeV to 980 TeV, limited at the high-energy end by a shortage of sufficiently energetic neutrinos.

At these energies, each individual proton or neutron in a nucleus acts independently, so the absorption depends on the number of protons or neutrons that each neutrino encounters. The Earth’s core is particularly dense, so absorption is largest there. By comparison, the most energetic neutrinos that have been studied at human-built particle accelerators were at energies below 0.4 TeV. Researchers have used these accelerators to aim beams containing an enormous number of these lower energy neutrinos at massive detectors, but only a very tiny fraction yield interactions.

IceCube researchers used data collected from May 2010 to May 2011, from a partial array of 79 “strings,” each containing 60 sensors embedded more than a mile deep in the ice.

Gary Binder, a UC Berkeley graduate student affiliated with Berkeley Lab’s Nuclear Science Division, developed the software that was used to fit IceCube’s data to a model describing how neutrinos propagate through the Earth.

From this, the software determined the cross-section that best fit the data. University of Wisconsin – Madison student Chris Weaver developed the code for selecting the detection events that Miarecki used.

Simulations to support the analysis have been conducted using supercomputers at the University of Wisconsin–Madison and at Berkeley Lab’s National Energy Research Scientific Computing Center (NERSC).

Physicists now hope to repeat the study using an expanded, multiyear analysis of data from the full 86-string IceCube array, which was completed in December 2010, and to look at higher ranges of neutrino energies for any hints of new physics beyond the Standard Model. IceCube has already detected multiple ultra-high-energy neutrinos, in the range of petaelectronvolts (PeV), which have a 1,000-times-higher energy than those detected in the TeV range.

Klein said, “Once we can reduce the uncertainties and can look at slightly higher energies, we can look at things like nuclear effects in the Earth, and collective electromagnetic effects.”

Binder added, “We can also study how much energy a neutrino transfers to a nucleus when it interacts, giving us another probe of nuclear structure and physics beyond the Standard Model.”

A longer term goal is to build a larger detector, which would enable scientists to study neutrinos of even higher energies. The proposed IceCube-Gen2 would be 10 times larger than IceCube. Its larger size would enable the detector to collect more data from neutrinos at very high energies.

Some scientists are looking to build an even larger detector, 100 cubic kilometers or more, using a new approach that searches for pulses of radio waves produced when very high energy neutrinos interact in the ice. Measurements of neutrino absorption by a radio-based detector could be used to search for new phenomena that go well beyond the physics accounted for in the Standard Model and could scrutinize the structure of atomic nuclei in greater detail than those of other experiments.

Miarecki said, “This is pretty exciting – I couldn’t have thought of a more interesting project.” 

Berkeley Lab’s National Energy Research Scientific Computing Center is a DOE Office of Science User Facility.

Read a related Berkeley Lab article about Sandra Miarecki, who performed much of the data analysis for this study: https://newscenter.lbl.gov/2017/11/22/flight-path-physics-success/.

###

The work was supported by the U.S. National Science Foundation-Office of Polar Programs, U.S. National Science Foundation-Physics Division, University of Wisconsin Alumni Research Foundation, Grid Laboratory of Wisconsin (GLOW) grid infrastructure at the University of Wisconsin–Madison, Open Science Grid (OSG) grid infrastructure, National Energy Research Scientific Computing Center, Louisiana Optical Network Initiative (LONI) grid computing resources, U.S. Department of Energy Office of Nuclear Physics, and United States Air Force Academy; Natural Sciences and Engineering Research Council of Canada, WestGrid and Compute/Calcul Canada; Swedish Research Council, Swedish Polar Research Secretariat, Swedish National Infrastructure for Computing (SNIC), and Knut and Alice Wallenberg Foundation, Sweden; German Ministry for Education and Research (BMBF), Deutsche Forschungsgemeinschaft (DFG), Helmholtz Alliance for Astroparticle Physics (HAP), Initiative and Networking Fund of the Helmholtz Association, Germany; Fund for Scientific Research (FNRS-FWO), FWO Odysseus programme, Flanders Institute to encourage scientific and technological research in industry (IWT), Belgian Federal Science Policy Office (Belspo); Marsden Fund, New Zealand; Australian Research Council; Japan Society for Promotion of Science (JSPS); the Swiss National Science Foundation (SNSF), Switzerland; National Research Foundation of Korea (NRF); Villum Fonden, Danish National Research Foundation (DNRF), Denmark.

The IceCube Neutrino Observatory was built under a National Science Foundation (NSF) Major Research Equipment and Facilities Construction grant, with assistance from partner funding agencies around the world. The NSF Office of Polar Programs and NSF Physics Division support the project with a Maintenance and Operations (M&O) grant. The University of Wisconsin–Madison is the lead institution for the IceCube Collaboration, coordinating data-taking and M&O activities.

X
X
X
  • Filters

  • × Clear Filters

Powering Up With a Smart Window

Window material repeatedly switches from being see-through to blocking the heat and converting sunlight into electricity.

Remnant Superconductivity From Invisible Stripes

Scientists used an intense light to unveil hidden rivers that transport electricity with no loss.

Columbia Researchers Squeeze Light into Nanoscale Devices and Circuits

Columbia investigators have made a major breakthrough in nanophotonics research, with their invention of a novel "home-built" cryogenic near-field optical microscope that has enabled them to directly image, for the first time, the propagation and dynamics of graphene plasmons at variable temperatures down to negative 250 degrees Celsius. If researchers can harness this nanolight, they will be able to improve sensing, subwavelength waveguiding, and optical transmission of signals.

Self-Assembling 3D Battery Would Charge in Seconds

A cross-campus collaboration led by Ulrich Wiesner, professor of engineering at Cornell University, has resulted in a novel energy storage device architecture that has the potential for lightning-quick charges for electronic devices.

Understanding the Generation of Light-Induced Electrical Current in Atomically Thin Nanomaterials

Scientists added an imaging capability to Brookhaven Lab's Center for Functional Nanomaterials that could provide the optoelectronic information needed to improve the performance of devices for power generation, communications, data storage, and lighting.

Diamond 'Spin-Off' Tech Could Lead to Low-Cost Medical Imaging and Drug Discovery Tools

An international team led by scientists at Berkeley Lab and UC Berkeley discovered how to exploit defects in nanoscale and microscale diamonds and potentially enhance the sensitivity of magnetic resonance imaging and nuclear magnetic resonance systems while eliminating the need for their costly and bulky superconducting magnets.

PROSPECTing For Antineutrinos

The Precision Reactor Oscillation and Spectrum Experiment (PROSPECT) has completed installation of a novel antineutrino detector that will probe the possible existence of a new form of matter - sterile neutrinos.

How to Cope with Cases of Mistaken Identity: MINERvA's Tale of Pions and Neutrinos

Neutral pion production is a major character in a story of mistaken identity worthy of an Agatha Christie novel.

Perfecting the Noise-Canceling Neutrino Detector

MicroBooNE neutrino experiment cuts through the noise, clearing the way for signals made by the hard-to-detect particle.

Supersonic Waves May Help Electronics Beat the Heat

Researchers at the Department of Energy's Oak Ridge National Laboratory made the first observations of waves of atomic rearrangements, known as phasons, propagating supersonically through a vibrating crystal lattice--a discovery that may dramatically improve heat transport in insulators and enable new strategies for heat management in future electronics devices.


  • Filters

  • × Clear Filters

Power to the People

The University of Utah College of Engineering has received a $2 million grant to create a laboratory and develop new technology for communities with backup power sources, known as microgrids, so they can quickly and more securely operate in the event of a massive power outage due to a natural disaster or cyberattack.

The U. S. Department of Energy Announces $34 Million for Small Business Research and Development Grants

U.S. Energy Secretary Rick Perry announced that the Department of Energy will award 219 grants totaling $34 million to 183 small businesses in 41 states. Funded through DOE's Small Business Innovation Research (SBIR) and Small Business Technology Transfer (STTR) programs, today's selections are for Phase I research and development.

Raising the Heat to Lower the Cost of Solar Energy

Sandia National Laboratories will receive $10.5 million from the Department of Energy to research and design a cheaper and more efficient solar energy system.The work focuses on refining a specific type of utility-scale solar energy technology that uses mirrors to reflect and concentrate sunlight onto a receiver on a tower.

Solar Turbines, Inc. Selects Penn State to Establish Center of Excellence in Gas Turbines

After completing an extensive evaluation of institutions of higher learning in the United States and Europe, Solar Turbines Incorporated has chosen Penn State as a university partner to establish a center of excellence in gas turbines. The center involves numerous faculty across Penn State's College of Engineering.

ORNL Facility Receives American Nuclear Society's Historic Landmark Designation

The American Nuclear Society has designated the Radiochemical Engineering Development Center at the Department of Energy's Oak Ridge National Laboratory an ANS Nuclear Historic Landmark, recognizing more than 50 years of isotope production and nuclear fuel cycle research.

Steven Cowley named director of DOE's Princeton Plasma Physics Laboratory

Steven Cowley, a theoretical physicist and international authority on fusion energy, has been named director of the U.S. Department of Energy's (DOE) Princeton Plasma Physics Laboratory (PPPL), effective July 1.

Scientists Turn X-ray Laser Into World's Fastest Water Heater

Scientists have used a powerful X-ray laser at the Department of Energy's SLAC National Accelerator Laboratory to heat water from room temperature to 100,000 degrees Celsius in less than a tenth of a picosecond, or millionth of a millionth of a second.

PNNL Part of a New National Center for Near-Atomic Resolution of Biological Molecules

A collaboration between the Pacific Northwest National Laboratory and Oregon Health & Science University has been chosen as a national center for a Nobel Prize-winning method of imaging, cryo-electron microscopy, that is revolutionizing structural biology.

SLAC Will Open One of Three NIH National Service Centers for Cryo-Electron Microscopy

The National Institutes of Health announced today that it will establish a national service and training center for cryogenic electron microscopy research at the Department of Energy's SLAC National Accelerator Laboratory.

Planck Collaboration Wins 2018 Gruber Cosmology Prize

The Planck Team--including researchers in Lawrence Berkeley National Laboratory's (Berkeley Lab's) Computational Research and Physics divisions--have been awarded the 2018 Gruber Cosmology Prize.


  • Filters

  • × Clear Filters

Powering Up With a Smart Window

Window material repeatedly switches from being see-through to blocking the heat and converting sunlight into electricity.

Remnant Superconductivity From Invisible Stripes

Scientists used an intense light to unveil hidden rivers that transport electricity with no loss.

Cracking the Code of Superconductivity and Magnetism

Neutron probes and theory reveal how electrons cooperate at lower temperatures.

The Secret to Measuring an Antineutrino's Energy

Scientists are developing better models that describe both neutrino and antineutrino data, which can offer insights into the nature of the universe.

How to Cope with Cases of Mistaken Identity: MINERvA's Tale of Pions and Neutrinos

Neutral pion production is a major character in a story of mistaken identity worthy of an Agatha Christie novel.

Perfecting the Noise-Canceling Neutrino Detector

MicroBooNE neutrino experiment cuts through the noise, clearing the way for signals made by the hard-to-detect particle.

Keeping Tabs on Polysulfides in Batteries

Optimizing lithium-sulfur battery electrolytes for long life.

Huge "Thermometer" Takes Temperatures of Tiny Samples

New spectroscopic technique measures heat in itty-bitty volumes that could reveal insights for electronics and energy technology.

Water, Water, Everywhere, but How Does It Flow?

Scientists use new X-ray technique to see how water moves at the molecular level.

Magnetized Plasmas That "Twist Light" Can Produce Powerful Microscopes and More

A non-twisting laser beam moving through magnetized plasma turns into an optical vortex that traps, rotates, and controls microscopic particles, opening new frontiers in imaging.


Spotlight

Monday May 07, 2018, 10:30 AM

Introducing Graduate Students Across the Globe to Photon Science

Brookhaven National Laboratory

Wednesday May 02, 2018, 04:05 PM

Students from Massachusetts and Washington Win DOE's 28th National Science Bowl(r)

Department of Energy, Office of Science

Thursday April 12, 2018, 07:05 PM

The Race for Young Scientific Minds

Argonne National Laboratory

Wednesday March 14, 2018, 02:05 PM

Q&A: Al Ashley Reflects on His Efforts to Diversify SLAC and Beyond

SLAC National Accelerator Laboratory

Thursday February 15, 2018, 12:05 PM

Insights on Innovation in Energy, Humanitarian Aid Highlight UVA Darden's Net Impact Week

University of Virginia Darden School of Business

Friday February 09, 2018, 11:05 AM

Ivy League Graduate, Writer and Activist with Dyslexia Visits CSUCI to Reframe the Concept of Learning Disabilities

California State University, Channel Islands

Wednesday January 17, 2018, 12:05 PM

Photographer Adam Nadel Selected as Fermilab's New Artist-in-Residence for 2018

Fermi National Accelerator Laboratory (Fermilab)

Wednesday January 17, 2018, 12:05 PM

Fermilab Computing Partners with Argonne, Local Schools for Hour of Code

Fermi National Accelerator Laboratory (Fermilab)

Wednesday December 20, 2017, 01:05 PM

Q&A: Sam Webb Teaches X-Ray Science from a Remote Classroom

SLAC National Accelerator Laboratory

Monday December 18, 2017, 01:05 PM

The Future of Today's Electric Power Systems

Rensselaer Polytechnic Institute (RPI)

Monday December 18, 2017, 12:05 PM

Supporting the Development of Offshore Wind Power Plants

Rensselaer Polytechnic Institute (RPI)

Tuesday October 03, 2017, 01:05 PM

Stairway to Science

Argonne National Laboratory

Thursday September 28, 2017, 12:05 PM

After-School Energy Rush

Argonne National Laboratory

Thursday September 28, 2017, 10:05 AM

Bringing Diversity Into Computational Science Through Student Outreach

Brookhaven National Laboratory

Thursday September 21, 2017, 03:05 PM

From Science to Finance: SLAC Summer Interns Forge New Paths in STEM

SLAC National Accelerator Laboratory

Thursday September 07, 2017, 02:05 PM

Students Discuss 'Cosmic Opportunities' at 45th Annual SLAC Summer Institute

SLAC National Accelerator Laboratory

Thursday August 31, 2017, 05:05 PM

Binghamton University Opens $70 Million Smart Energy Building

Binghamton University, State University of New York

Wednesday August 23, 2017, 05:05 PM

Widening Horizons for High Schoolers with Code

Argonne National Laboratory

Saturday May 20, 2017, 12:05 PM

Rensselaer Polytechnic Institute Graduates Urged to Embrace Change at 211th Commencement

Rensselaer Polytechnic Institute (RPI)

Monday May 15, 2017, 01:05 PM

ORNL, University of Tennessee Launch New Doctoral Program in Data Science

Oak Ridge National Laboratory

Friday April 07, 2017, 11:05 AM

Champions in Science: Profile of Jonathan Kirzner

Department of Energy, Office of Science

Wednesday April 05, 2017, 12:05 PM

High-Schooler Solves College-Level Security Puzzle From Argonne, Sparks Interest in Career

Argonne National Laboratory

Tuesday March 28, 2017, 12:05 PM

Champions in Science: Profile of Jenica Jacobi

Department of Energy, Office of Science

Friday March 24, 2017, 10:40 AM

Great Neck South High School Wins Regional Science Bowl at Brookhaven Lab

Brookhaven National Laboratory

Wednesday February 15, 2017, 04:05 PM

Middle Schoolers Test Their Knowledge at Science Bowl Competition

Argonne National Laboratory

Friday January 27, 2017, 04:00 PM

Haslam Visits ORNL to Highlight State's Role in Discovering Tennessine

Oak Ridge National Laboratory

Tuesday November 08, 2016, 12:05 PM

Internship Program Helps Foster Development of Future Nuclear Scientists

Oak Ridge National Laboratory

Friday May 13, 2016, 04:05 PM

More Than 12,000 Explore Jefferson Lab During April 30 Open House

Thomas Jefferson National Accelerator Facility

Monday April 25, 2016, 05:05 PM

Giving Back to National Science Bowl

Ames Laboratory

Friday March 25, 2016, 12:05 PM

NMSU Undergrad Tackles 3D Particle Scattering Animations After Receiving JSA Research Assistantship

Thomas Jefferson National Accelerator Facility

Tuesday February 02, 2016, 10:05 AM

Shannon Greco: A Self-Described "STEM Education Zealot"

Princeton Plasma Physics Laboratory

Monday November 16, 2015, 04:05 PM

Rare Earths for Life: An 85th Birthday Visit with Mr. Rare Earth

Ames Laboratory

Tuesday October 20, 2015, 01:05 PM

Meet Robert Palomino: 'Give Everything a Shot!'

Brookhaven National Laboratory

Tuesday April 22, 2014, 11:30 AM

University of Utah Makes Solar Accessible

University of Utah

Wednesday March 06, 2013, 03:40 PM

Student Innovator at Rensselaer Polytechnic Institute Seeks Brighter, Smarter, and More Efficient LEDs

Rensselaer Polytechnic Institute (RPI)

Friday November 16, 2012, 10:00 AM

Texas Tech Energy Commerce Students, Community Light up Tent City

Texas Tech University

Wednesday November 23, 2011, 10:45 AM

Don't Get 'Frosted' Over Heating Your Home This Winter

Temple University

Wednesday July 06, 2011, 06:00 PM

New Research Center To Tackle Critical Challenges Related to Aircraft Design, Wind Energy, Smart Buildings

Rensselaer Polytechnic Institute (RPI)

Friday April 22, 2011, 09:00 AM

First Polymer Solar-Thermal Device Heats Home, Saves Money

Wake Forest University

Friday April 15, 2011, 12:25 PM

Like Superman, American University Will Get Its Energy from the Sun

American University

Thursday February 10, 2011, 05:00 PM

ARRA Grant to Help Fund Seminary Building Green Roof

University of Chicago

Tuesday December 07, 2010, 05:00 PM

UC San Diego Installing 2.8 Megawatt Fuel Cell to Anchor Energy Innovation Park

University of California San Diego

Monday November 01, 2010, 12:50 PM

Rensselaer Smart Lighting Engineering Research Center Announces First Deployment of New Technology on Campus

Rensselaer Polytechnic Institute (RPI)

Friday September 10, 2010, 12:40 PM

Ithaca College Will Host Regional Clean Energy Summit

Ithaca College

Tuesday July 27, 2010, 10:30 AM

Texas Governor Announces $8.4 Million Award to Create Renewable Energy Institute

Texas Tech University

Friday May 07, 2010, 04:20 PM

Creighton University to Offer New Alternative Energy Program

Creighton University

Wednesday May 05, 2010, 09:30 AM

National Engineering Program Seeks Subject Matter Experts in Energy

JETS Junior Engineering Technical Society

Wednesday April 21, 2010, 12:30 PM

Students Using Solar Power To Create Sustainable Solutions for Haiti, Peru

Rensselaer Polytechnic Institute (RPI)





Showing results

0-4 Of 2215