DOE News
    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.
    • 2019-04-18 15:05:42
    • Article ID: 711563

    The Weak Side of the Proton

    A precision measurement of the proton's weak charge narrows the search for new physics.

    • Credit: Jefferson Lab

      Researchers conducted the Q-weak experiment in Jefferson Lab’s Experimental Hall C, and their goal was to very precisely measure the proton's weak charge, a term that quantifies the influence that the weak force can exert on protons. Engineers installed the Q-weak apparatus, shown here, in the Hall for the experimental run, which concluded in 2012.

    The Science

    The weak force is one of the four fundamental forces in our universe, along with gravity, electromagnetism, and the strong force. Researchers have made the first experimental determination of the weak charge of the proton, a measure of the precise strength of the weak force’s influence on the proton. They found that the measurement agrees well with predictions using the Standard Model. The Standard Model is the current theory used to describe how fundamental particles interact with each other.

    The Impact

    The determination of the proton’s weak charge provides a precision test of the weak force.  As it is in excellent agreement with the theoretical prediction of this parameter derived from the Standard Model, this constrains some possible types of new particles and forces beyond our present knowledge.

    Summary

    The weak force’s effects can be observed in our everyday world: it initiates the chain of reactions that power the sun, and it provides a mechanism for radioactive decays that partially heat the Earth’s core and that also enable doctors to detect disease inside the body without surgery. The weak force acts directly on subatomic particles, such as the protons, neutrons, and electrons that make up atoms. These particles carry a weak charge, a measure of the influence that the weak force can exert on them. To measure the weak charge of the proton, scientists directed an intense beam of electrons generated by Jefferson Lab’s Continuous Electron Beam Accelerator Facility onto a target containing cold liquid hydrogen. A precise, custom-built apparatus detected the electrons that scattered from the protons inside the target. The electrons in the beam were highly polarized — meaning that the electrons were mostly “spinning” in one direction, parallel or anti-parallel to the beam direction. By precisely and rapidly reversing the direction of polarization, the nuclear physicists measured the proton’s weak charge. The new result is in excellent agreement with the predictions of the Standard Model of particle physics, and so it serves as a test of the model and can impact its predictions. For example, this result has set limits on the possible existence of leptoquarks, which are hypothetical particles that can reverse the identities of two broad classes of very different fundamental particles — turning quarks (the building blocks of nuclear matter) into leptons (electrons and their heavier counterparts) and vice versa.

    Numerous technical achievements made this experiment possible. These include the high-current, high-polarization, extremely stable electron beam provided by the Continuous Electron Beam Accelerator Facility; the world's highest-power cryogenic hydrogen target; extremely radiation-resistant Cerenkov detectors; ultra-low noise electronics for signal readout and beam current measurement; and a system that measures the beam polarization to better than 1%.

    Funding

    This work was supported by the Department of Energy, Office of Science, Nuclear Physics; the National Science Foundation; the Natural Sciences and Engineering Research Council of Canada; and the Canadian Foundation for Innovation, with matching and in-kind contributions from a number of the collaborating institutions.

    Publications

    The Jefferson Lab Qweak Collaboration, “Precision measurement of the weak charge of the proton.” Nature 557, 207 (2018). [DOI: 10.1038/s41586-018-0096-0]

    • other-fb
    • other-tw
    X
    X
    X
    • Filters

    • × Clear Filters
    Designer Frameworks for Refining Higher Octane Fuels

    Designer Frameworks for Refining Higher Octane Fuels

    Metal-organic frameworks designed with a topology-guided approach show higher efficiency than commercial benchmarks.

    Advanced NMR at Ames Lab Captures New Details in Nanoparticle Structures

    Advanced NMR at Ames Lab Captures New Details in Nanoparticle Structures

    Advanced nuclear magnetic resonance (NMR) techniques at the U.S. Department of Energy'sAmes Laboratory have revealed surprising details about the structure of a key group ofmaterials in nanotechology, mesoporous silica nanoparticles (MSNs), and the placement of their active chemical sites.

    Plants' Oil-Production Accelerator Also Activates the Brakes

    Plants' Oil-Production Accelerator Also Activates the Brakes

    UPTON, NY--Scientists studying plant biochemistry at the U.S. Department of Energy's Brookhaven National Laboratory recently made a surprising discovery: They found that a protein that turns on oil synthesis also activates a protein that puts the brakes on the same process. In a paper just published in the journal Plant Physiology, they describe how this seemingly paradoxical system keeps oil precursors perfectly balanced to meet plants' needs.

    A Trojan Horse for Fusion Disruptions

    A Trojan Horse for Fusion Disruptions

    Thin-walled diamond shells carry payloads of boron dust; the dust mitigates destructive plasma disruptions in fusion confinement systems.

    Mineral Discovery Made Easier: X-Ray Technique Shines a New Light on Tiny, Rare Crystals

    Mineral Discovery Made Easier: X-Ray Technique Shines a New Light on Tiny, Rare Crystals

    Like a tiny needle in a sprawling hayfield, a single crystal grain measuring just tens of millionths of a meter - found in a borehole sample drilled in Central Siberia - had an unexpected chemical makeup. And a specialized X-ray technique in use at Berkeley Lab confirmed the sample's uniqueness and paved the way for its formal recognition as a newly discovered mineral: ognitite.

    Neutrons get a wider angle on DNA and RNA to advance 3D models

    Neutrons get a wider angle on DNA and RNA to advance 3D models

    Scientists from the National Institute of Standards and Technology (NIST) and the University of Maryland used neutrons at Oak Ridge National Laboratory (ORNL) to capture new information about DNA and RNA molecules and enable more accurate computer simulations of how they interact with everything from proteins to viruses.

    Found: New Bismuth Compounds in Well-Known Systems of Two Elements

    Found: New Bismuth Compounds in Well-Known Systems of Two Elements

    Scientists discover an unexpected source of new materials, with potential for energy applications.

    A quick liquid flip helps explain how morphing materials store information

    A quick liquid flip helps explain how morphing materials store information

    Experiments at SLAC's X-ray laser reveal in atomic detail how two distinct liquid phases in these materials enable fast switching between glassy and crystalline states that represent 0s and 1s in memory devices.

    A New Manufacturing Process for Aluminum Alloys

    A New Manufacturing Process for Aluminum Alloys

    Using a novel Solid Phase Processing approach, a research team at Pacific Northwest National Laboratory eliminated several steps that are required during conventional extrusion processing of aluminum alloy powders, while also achieving a significant increase in product ductility. This is good news for sectors such as the automotive industry, where the high cost of manufacturing has historically limited the use of high-strength aluminum alloys made from powders.

    Flowing for Function

    Flowing for Function

    A flowing magnetically responsive liquid seamlessly regulates the shape and properties of solids, letting them perform an array of jobs.


    • Filters

    • × Clear Filters

    Energy Department to Invest $32 Million in Computer Design of Materials

    The U.S. Department of Energy announced that it will invest $32 million over the next four years to accelerate the design of new materials through use of supercomputers.

    Demarteau to head ORNL Physics Division

    Demarteau to head ORNL Physics Division

    The Department of Energy's Oak Ridge National Laboratory has named Marcel Demarteau as Physics Division Director, effective June 17.

    PPPL and Oak Ridge manage new DOE program designed to speed development of fusion energy with private-public partnerships

    PPPL and Oak Ridge manage new DOE program designed to speed development of fusion energy with private-public partnerships

    Feature describes PPPL role in innovative DOE program to promote public-private partnerships to speed development of fusion energy.

    ORNL welcomes seven new research fellows to Innovation Crossroads

    ORNL welcomes seven new research fellows to Innovation Crossroads

    Oak Ridge National Laboratory welcomed seven technology innovators to join the third cohort of Innovation Crossroads, the Southeast's only entrepreneurial research and development program based at a U.S. Department of Energy national laboratory.

    New DOE program connects fusion companies with national labs, taps ORNL to lead

    New DOE program connects fusion companies with national labs, taps ORNL to lead

    The Department of Energy has established the Innovation Network for Fusion Energy program, or INFUSE, to encourage private-public research partnerships for overcoming challenges in fusion energy development.

    Department of Energy Announces $75 Million for High Energy Physics Research

    The U.S. Department of Energy (DOE) announced $75 million in funding for 66 university research awards on a range of topics in high energy physics to advance knowledge of how the universe works at its most fundamental level.

    Ames Laboratory names James Morris Chief Research Officer

    Ames Laboratory names James Morris Chief Research Officer

    Dr. James Morris has been named Chief Research Officer at the Department of Energy's (DOE) Ames Laboratory. His appointment follows an extensive search and will be effective June 17, 2019.

    Four scientists at PPPL awarded national and international honors

    Four scientists at PPPL awarded national and international honors

    Feature profiles four PPPL scientists who have received high honors.

    Brookhaven's Mircea Cotlet Named a Battelle "Inventor of the Year"

    Brookhaven's Mircea Cotlet Named a Battelle "Inventor of the Year"

    The global science and technology organization Battelle recognized materials scientist Mircea Cotlet of Brookhaven Lab's Center for Functional Nanomaterials for his research in applying self-assembly methods to control the interfaces between nanomaterials and other light-interacting components.

    Berkeley Lab Project to Pinpoint Methane 'Super Emitters'

    Berkeley Lab Project to Pinpoint Methane 'Super Emitters'

    Methane, a potent greenhouse gas that traps about 30 times more heat than carbon dioxide, is commonly released from rice fields, dairies, landfills, and oil and gas facilities - all of which are plentiful in California. Now Berkeley Lab has been awarded $6 million by the state to find "super emitters" of methane in an effort to quantify and potentially mitigate methane emissions.


    • Filters

    • × Clear Filters
    Designer Frameworks for Refining Higher Octane Fuels

    Designer Frameworks for Refining Higher Octane Fuels

    Metal-organic frameworks designed with a topology-guided approach show higher efficiency than commercial benchmarks.

    A Trojan Horse for Fusion Disruptions

    A Trojan Horse for Fusion Disruptions

    Thin-walled diamond shells carry payloads of boron dust; the dust mitigates destructive plasma disruptions in fusion confinement systems.

    Found: New Bismuth Compounds in Well-Known Systems of Two Elements

    Found: New Bismuth Compounds in Well-Known Systems of Two Elements

    Scientists discover an unexpected source of new materials, with potential for energy applications.

    Flowing for Function

    Flowing for Function

    A flowing magnetically responsive liquid seamlessly regulates the shape and properties of solids, letting them perform an array of jobs.

    Superconducting Films for Particle Acceleration

    Superconducting Films for Particle Acceleration

    Researchers demonstrated record accelerating cavity performance using a technique that could lead to significant cost savings.

    Parceling Particle Beams

    Parceling Particle Beams

    Beam chopper cuts accelerator-generated ion beams under highly demanding conditions.

    An Interaction of Slipping Beams

    An Interaction of Slipping Beams

    Successful models of the fraught dynamics of two particle beams in close contact lead to smoother sailing in an area of particle acceleration.

    At DOE's Manufacturing Demonstration Facility, science drives next-gen creations

    At DOE's Manufacturing Demonstration Facility, science drives next-gen creations

    American ingenuity is providing radical productivity improvements from advanced materials and robotic systems developed at the Department of Energy's Manufacturing Demonstration Facility at Oak Ridge National Laboratory.

    Computer Simulation Shows Astrophysical Particle Acceleration

    Computer Simulation Shows Astrophysical Particle Acceleration

    Particles act in a way that justifies extrapolating simulation results to astrophysical scales.

    High-Fidelity Multiphysics Simulations to Improve Nuclear Reactor Safety and Economics

    High-Fidelity Multiphysics Simulations to Improve Nuclear Reactor Safety and Economics

    Engineers can model heat distribution in reactor designs with fewer or no approximations.


    Spotlight

    ILSAMP Symposium showcases benefits for diverse students, STEM pipeline
    Monday May 20, 2019, 12:05 PM

    ILSAMP Symposium showcases benefits for diverse students, STEM pipeline

    Argonne National Laboratory

    Integrating Scientific Computing into Science Curricula
    Monday May 13, 2019, 11:05 AM

    Integrating Scientific Computing into Science Curricula

    Brookhaven National Laboratory

    Students from Minnesota and Massachusetts Win DOE's 29th National Science Bowl(r)
    Monday April 29, 2019, 02:05 PM

    Students from Minnesota and Massachusetts Win DOE's 29th National Science Bowl(r)

    Department of Energy, Office of Science

    DOE's Science Graduate Student Research Program Selects 70 Students to Pursue Research at DOE Laboratories
    Friday April 12, 2019, 03:05 PM

    DOE's Science Graduate Student Research Program Selects 70 Students to Pursue Research at DOE Laboratories

    Department of Energy, Office of Science

    Young Women's Conference in STEM seeks to change the statistics one girl at a time
    Thursday March 28, 2019, 03:05 PM

    Young Women's Conference in STEM seeks to change the statistics one girl at a time

    Princeton Plasma Physics Laboratory

    Students team with Argonne scientists and engineers to learn about STEM careers
    Tuesday March 12, 2019, 05:05 PM

    Students team with Argonne scientists and engineers to learn about STEM careers

    Argonne National Laboratory

    Lynbrook High wins 2019 SLAC Regional Science Bowl competition
    Wednesday February 13, 2019, 02:05 PM

    Lynbrook High wins 2019 SLAC Regional Science Bowl competition

    SLAC National Accelerator Laboratory

    Equipping the next generation for a technological revolution
    Thursday January 24, 2019, 01:05 PM

    Equipping the next generation for a technological revolution

    Argonne National Laboratory

    Chemistry intern inspired by Argonne's real-world science
    Friday January 18, 2019, 05:05 PM

    Chemistry intern inspired by Argonne's real-world science

    Argonne National Laboratory

    Chasing a supernova
    Friday January 18, 2019, 04:05 PM

    Chasing a supernova

    Argonne National Laboratory

    Argonne intern streamlines the beamline
    Tuesday January 08, 2019, 02:05 PM

    Argonne intern streamlines the beamline

    Argonne National Laboratory

    Research on Light-Matter Interaction Could Lead to Improved Electronic and Optoelectronic Devices
    Thursday October 11, 2018, 04:00 PM

    Research on Light-Matter Interaction Could Lead to Improved Electronic and Optoelectronic Devices

    Rensselaer Polytechnic Institute (RPI)

    Innovating Our Energy Future
    Wednesday October 03, 2018, 07:05 PM

    Innovating Our Energy Future

    Oregon State University, College of Engineering

    Physics graduate student takes her thesis research to a Department of Energy national lab
    Tuesday October 02, 2018, 03:05 PM

    Physics graduate student takes her thesis research to a Department of Energy national lab

    University of Alabama at Birmingham

    Friday September 21, 2018, 01:05 PM

    "Model" students enjoy Argonne campus life

    Argonne National Laboratory

    Writing Code for a More Skilled and Diverse STEM Workforce
    Thursday September 06, 2018, 01:05 PM

    Writing Code for a More Skilled and Diverse STEM Workforce

    Brookhaven National Laboratory

    New graduate student summer school launches at Princeton Plasma Physics Laboratory
    Tuesday September 04, 2018, 11:30 AM

    New graduate student summer school launches at Princeton Plasma Physics Laboratory

    Princeton Plasma Physics Laboratory

    The Gridlock State
    Friday August 31, 2018, 06:05 PM

    The Gridlock State

    California State University (CSU) Chancellor's Office

    Meet Jasmine Hatcher and Trishelle Copeland-Johnson
    Friday August 31, 2018, 02:05 PM

    Meet Jasmine Hatcher and Trishelle Copeland-Johnson

    Brookhaven National Laboratory

    Argonne hosts Modeling, Experimentation and Validation Summer School
    Friday August 24, 2018, 11:05 AM

    Argonne hosts Modeling, Experimentation and Validation Summer School

    Argonne National Laboratory

    Students affected by Hurricane Maria bring their research to SLAC
    Wednesday August 22, 2018, 01:05 PM

    Students affected by Hurricane Maria bring their research to SLAC

    SLAC National Accelerator Laboratory

    Brookhaven Lab Pays Tribute to 2018 Summer Interns
    Wednesday August 22, 2018, 10:05 AM

    Brookhaven Lab Pays Tribute to 2018 Summer Interns

    Brookhaven National Laboratory

    Changing How Buildings Are Made
    Monday August 20, 2018, 12:05 PM

    Changing How Buildings Are Made

    Washington University in St. Louis

    CSUMB Selected to Host Architecture at Zero Competition in 2019
    Thursday August 16, 2018, 12:05 PM

    CSUMB Selected to Host Architecture at Zero Competition in 2019

    California State University, Monterey Bay

    Department of Energy Invests $64 Million in Advanced Nuclear Technology
    Friday July 20, 2018, 03:00 PM

    Department of Energy Invests $64 Million in Advanced Nuclear Technology

    Rensselaer Polytechnic Institute (RPI)

    Professor Miao Yu Named the Priti and Mukesh Chatter '82 Career Development Professor
    Thursday July 19, 2018, 05:00 PM

    Professor Miao Yu Named the Priti and Mukesh Chatter '82 Career Development Professor

    Rensselaer Polytechnic Institute (RPI)

    2018 RHIC & AGS Annual Users' Meeting: 'Illuminating the QCD Landscape'
    Tuesday July 03, 2018, 11:05 AM

    2018 RHIC & AGS Annual Users' Meeting: 'Illuminating the QCD Landscape'

    Brookhaven National Laboratory

    Argonne welcomes <em>The Martian</em> author Andy Weir
    Friday June 29, 2018, 06:05 PM

    Argonne welcomes The Martian author Andy Weir

    Argonne National Laboratory

    Creating STEM Knowledge and Innovations to Solve Global Issues Like Water, Food, and Energy
    Monday June 18, 2018, 09:55 AM

    Creating STEM Knowledge and Innovations to Solve Global Issues Like Water, Food, and Energy

    Illinois Mathematics and Science Academy (IMSA)

    Professor Emily Liu Receives $1.8 Million DoE Award for Solar Power Systems Research
    Friday June 15, 2018, 10:00 AM

    Professor Emily Liu Receives $1.8 Million DoE Award for Solar Power Systems Research

    Rensselaer Polytechnic Institute (RPI)

    Celebrating 40 years of empowerment in science
    Thursday June 07, 2018, 03:05 PM

    Celebrating 40 years of empowerment in science

    Argonne National Laboratory

    Introducing Graduate Students Across the Globe to Photon Science
    Monday May 07, 2018, 10:30 AM

    Introducing Graduate Students Across the Globe to Photon Science

    Brookhaven National Laboratory

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

    The Race for Young Scientific Minds
    Thursday April 12, 2018, 07:05 PM

    The Race for Young Scientific Minds

    Argonne National Laboratory

    Q&A: Al Ashley Reflects on His Efforts to Diversify SLAC and Beyond
    Wednesday March 14, 2018, 02:05 PM

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

    SLAC National Accelerator Laboratory

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

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

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

    Fermilab Computing Partners with Argonne, Local Schools for Hour of Code
    Wednesday January 17, 2018, 12:05 PM

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

    Fermi National Accelerator Laboratory (Fermilab)

    Q&A: Sam Webb Teaches X-Ray Science from a Remote Classroom
    Wednesday December 20, 2017, 01:05 PM

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

    SLAC National Accelerator Laboratory

    The Future of Today's Electric Power Systems
    Monday December 18, 2017, 01:05 PM

    The Future of Today's Electric Power Systems

    Rensselaer Polytechnic Institute (RPI)

    Supporting the Development of Offshore Wind Power Plants
    Monday December 18, 2017, 12:05 PM

    Supporting the Development of Offshore Wind Power Plants

    Rensselaer Polytechnic Institute (RPI)

    Stairway to Science
    Tuesday October 03, 2017, 01:05 PM

    Stairway to Science

    Argonne National Laboratory

    After-School Energy Rush
    Thursday September 28, 2017, 12:05 PM

    After-School Energy Rush

    Argonne National Laboratory

    Bringing Diversity Into Computational Science Through Student Outreach
    Thursday September 28, 2017, 10:05 AM

    Bringing Diversity Into Computational Science Through Student Outreach

    Brookhaven National Laboratory

    From Science to Finance: SLAC Summer Interns Forge New Paths in STEM
    Thursday September 21, 2017, 03:05 PM

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

    SLAC National Accelerator Laboratory





    Showing results

    0-4 Of 2215