Nav: Home

The search for dark matter: Axions have ever fewer places to hide

February 14, 2018

If they existed, axions - one of the candidates for particles of the mysterious dark matter - could interact with the matter forming our world, but they would have to do this to a much, much weaker extent than it has seemed up to now. New, rigorous constraints on the properties of axions have been imposed by an international team of scientists responsible for the nEDM experiment.

The latest analysis of measurements of the electrical properties of ultracold neutrons published in the scientific journal Physical Review X has led to surprising conclusions. On the basis of data collected in the nEDM (Electric Dipole Moment of Neutron) experiment, an international group of physicists - including the Cracow-based scientists from the Institute of Nuclear Physics of the Polish Academy of Sciences (IFJ PAN) and the Jagiellonian University - showed in an innovative way that axions, the hypothetical particles that may form cold dark matter, if they existed, would have to comply with much stricter limitations than previously believed with regard to their mass and manners of interacting with ordinary matter. The presented results are the first laboratory data imposing limits on the potential interactions of axions with nucleons (i.e. protons or neutrons) and gluons (the particles bonding quarks in nucleons).

"Measurements of the electric dipole moment of neutrons have been conducted by our international group for a good dozen or so years. For most of this time, none of us suspected that any traces associated with potential particles of dark matter might be hidden in the collected data. Only recently, theoreticians have suggested such a possibility and we eagerly took the opportunity to verify the hypotheses about the properties of axions," says Dr. Adam Kozela (IFJ PAN), one of the participants of the experiment.

The first traces of dark matter were found when analyzing the movements of stars in galaxies and galaxies in galaxy clusters. The pioneer of statistical research on star movements was the Polish astronomer Marian Kowalski. Already in 1859 he noticed that the movements of stars close to us could not be explained solely by the movement of the Sun. This was the first observational premise suggesting the rotation of the Milky Way (Kowalski is thus the man who "shook the foundations" of the galaxy). In 1933, the Swiss Fritz Zwicky went one step further. He analyzed the movements of structures in the Coma galaxy cluster by several methods. He then noticed that they moved as if there were a much larger amount of matter in their surroundings than that seen by astronomers.

Despite decades of searching, the nature of dark matter, which (as background microwave radiation measurements suggest) there should be almost 5.5 times as much of in the Universe as ordinary matter, is still unknown. Theoreticians have constructed a whole plethora of models predicting the existence of particles that are more exotic or less so, that may be responsible for the existence of dark matter. Among the candidates are axions. If they did exist, these extremely light particles would interact with ordinary matter almost exclusively by gravity. Almost, because current models predict that in certain situations a photon could change into an axion, and after some time this would transform back into a photon. This hypothetical phenomenon was and is the basis of the famous "lighting through a wall" experiments. These involve researchers directing an intense beam of laser light onto a thick obstacle, counting on the fact that at least a few photons will change into axions that will penetrate the wall without any major problems. After passing through the wall, some axions could become photons again with features exactly like the photons originally falling on the wall.

Experiments related to measuring the electric dipole moment of neutrons, conducted by a group of researchers from Australia, Belgium, France, Germany, Poland, Switzerland and Great Britain, have nothing to do with photons. The measuring apparatus that was initially located at the Institut Laue-Langevin (ILL) in Grenoble (France) is currently operating at the Laboratory for Particle Physics at the Paul Scherrer Institute (PSI) in Villigen (Switzerland). In experiments that have been conducted for over ten years, scientists measure changes in the frequency of nuclear magnetic resonance (NMR) of neutrons and mercury atoms that are in a vacuum chamber in the presence of electric, magnetic and gravitational fields. These measurements enable conclusions to be drawn about the precession of neutrons and mercury atoms, and consequently on their dipole moments.

To the surprise of many physicists, in recent years theoretical works have appeared that envisage the possibility of axions interacting with gluons and nucleons. Depending on the mass of the axions, these interactions could result in smaller or larger disturbances having a character of oscillations of dipole electrical moments of nucleons, or even whole atoms. The theoreticians' predictions meant that experiments conducted as part of the nEDM cooperation could contain valuable information about the existence and properties of potential particles of dark matter.

"In the data from the experiments at PSI, our colleagues conducting the analysis looked for frequency changes with periods in the order of minutes, and in the results from ILL - in the order of days. The latter would appear if there was an axion wind, that is, if the axions in the near Earth space were moving in a specific direction. Since the Earth is spinning, at different times of the day our measuring equipment would change its orientation relative to the axion wind, and this should result in cyclical, daily changes in the oscillations recorded by us," explains Dr. Kozela.

The results of the search turned out to be negative: no trace of the existence of axions with masses between 10-24 and 10-17 electronvolts were found (for comparison: the mass of an electron is more than half a million electronvolts). In addition, scientists managed to tighten the constraints imposed by theory on the interaction of axions with nucleons by 40 times. In the case of potential interactions with gluons, the restrictions have increased even more, more than one thousand-fold. So then, if axions do exist, in the current theoretical models they have fewer and fewer places to hide.
-end-
The Henryk Niewodniczanski Institute of Nuclear Physics (IFJ PAN) is currently the largest research institute of the Polish Academy of Sciences. The broad range of studies and activities of IFJ PAN includes basic and applied research, ranging from particle physics and astrophysics, through hadron physics, high-, medium-, and low-energy nuclear physics, condensed matter physics (including materials engineering), to various applications of methods of nuclear physics in interdisciplinary research, covering medical physics, dosimetry, radiation and environmental biology, environmental protection, and other related disciplines. The average yearly yield of the IFJ PAN encompasses more than 600 scientific papers in the Journal Citation Reports published by the Thomson Reuters. The part of the Institute is the Cyclotron Centre Bronowice (CCB) which is an infrastructure, unique in Central Europe, to serve as a clinical and research centre in the area of medical and nuclear physics. IFJ PAN is a member of the Marian Smoluchowski Krakow Research Consortium: "Matter-Energy-Future" which possesses the status of a Leading National Research Centre (KNOW) in physics for the years 2012-2017. The Institute is of A+ Category (leading level in Poland) in the field of sciences and engineering.

CONTACTS:

Dr. Adam Kozela
The Institute of Nuclear Physics Polish Academy of Sciences
tel.: +48 12 662 8290, +48 12 662 6120
adam.kozela@ifj.edu.pl

SCIENTIFIC PAPERS:

"Search for Axionlike Dark Matter through Nuclear Spin Precession in Electric and Magnetic Fields" C. Abel et al.
Physical Review X 7, 041034 (2017)
DOI: 10.1103/PhysRevX.7.041034

LINKS:

http://www.ifj.edu.pl/ The website of the Institute of Nuclear Physics Polish Academy of Sciences.

http://press.ifj.edu.pl/ Press releases of the Institute of Nuclear Physics Polish Academy of Sciences.

IMAGES:

IFJ180214b_fot01s.jpg
HR: http://press.ifj.edu.pl/news/2018/02/14/IFJ180214b_fot01.jpg

The distribution of dark matter (colored in blue) in six galaxy clusters, mapped from the visible-light images from the Hubble Space Telescope. (Source: NASA, ESA, STScI, and CXC)

The Henryk Niewodniczanski Institute of Nuclear Physics Polish Academy of Sciences

Related Dark Matter Articles:

Does dark matter annihilate quicker in the Milky Way?
Researchers at the Tata Institute of Fundamental Research in Mumbai have proposed a theory that predicts how dark matter may be annihilating much more rapidly in the Milky Way, than in smaller or larger galaxies and the early Universe.
Origin of Milky Way's hypothetical dark matter signal may not be so dark
A mysterious gamma-ray glow at the center of the Milky Way is most likely caused by pulsars.
A new look at the nature of dark matter
A new study suggests that the gravitational waves detected by the LIGO experiment must have come from black holes generated during the collapse of stars, and not in the earliest phases of the Universe.
Dark matter may be smoother than expected
Analysis of a giant new galaxy survey, made with ESO's VLT Survey Telescope in Chile, suggests that dark matter may be less dense and more smoothly distributed throughout space than previously thought.
Supercomputer comes up with a profile of dark matter
In the search for the mysterious dark matter, physicists have used elaborate computer calculations to come up with an outline of the particles of this unknown form of matter.
Mapping the 'dark matter' of human DNA
Researchers from ERIBA, Radboud UMC, XJTU, Saarland University, CWI and UMC Utrecht have made a big step towards a better understanding of the human genome.
Reconciling dwarf galaxies with dark matter
Dwarf galaxies are enigmas wrapped in riddles. Although they are the smallest galaxies, they represent some of the biggest mysteries about our universe.
Did gravitational wave detector find dark matter?
When an astronomical observatory detected two black holes colliding in deep space, scientists celebrated confirmation of Einstein's prediction of gravitational waves.
Dark matter does not contain certain axion-like particles
Researchers at Stockholm University are getting closer to corner light dark-matter particle models.
SDU researchers present a new model for what dark matter might be
There are indications that we might never see the universe's mysterious dark matter.

Related Dark Matter Reading:

Dark Matter: A Novel
by Blake Crouch (Author)

A mindbending, relentlessly surprising thriller from the author of the bestselling Wayward Pines trilogy.

“Are you happy with your life?”

 
Those are the last words Jason Dessen hears before the masked abductor knocks him unconscious.
 
Before he awakens to find himself strapped to a gurney, surrounded by strangers in hazmat suits.
 
Before a man Jason’s never met smiles down at him and says, “Welcome back, my friend.” 
 
In this world he’s woken up to, Jason’s life is not the one he knows. His wife is not his wife.... View Details


Dark Matters: On the Surveillance of Blackness
by Simone Browne (Author)

In Dark Matters Simone Browne locates the conditions of blackness as a key site through which surveillance is practiced, narrated, and resisted. She shows how contemporary surveillance technologies and practices are informed by the long history of racial formation and by the methods of policing black life under slavery, such as branding, runaway slave notices, and lantern laws. Placing surveillance studies into conversation with the archive of transatlantic slavery and its afterlife, Browne draws from black feminist theory, sociology, and cultural studies to analyze texts as diverse as... View Details


Dark Matter: A Century of Speculative Fiction from the African Diaspora
by Sheree Renée Thomas (Editor)

This volume introduces black science fiction, fantasy, and speculative fiction writers to the generations of readers who have not had the chance to explore the scope and diversity among African-American writers. View Details


Dark Matter and the Dinosaurs: The Astounding Interconnectedness of the Universe
by Lisa Randall (Author)

“A cracking read, combining storytelling of the highest order with a trove of information. . . . What’s remarkable is that it all fits together.”—Wall Street Journal

“Successful science writing tells a complete story of the ‘how’—the methodical marvel building up to the ‘why’—and Randall does just that.”—New York Times Book Review

“[Randall] is a lucid explainer, street-wise and informal. Without jargon or mathematics, she steers us through centuries of sometimes tortuous astronomical... View Details


Dark Matter
by Michelle Paver (Author)

January 1937. 28-year-old Jack is poor, lonely and desperate to change his life. So when he's offered the chance to join an Arctic expedition, he jumps at it. After they reach the remote, uninhabited bay where they will camp for the next year, Gruhuken, Jack feels a creeping unease. One by one, his companions are forced to leave. View Details


Pines (The Wayward Pines Trilogy)
by Blake Crouch (Author)

The one-million copy bestseller that inspired the Fox TV show.

Secret service agent Ethan Burke arrives in Wayward Pines, Idaho, with a clear mission: locate and recover two federal agents who went missing in the bucolic town one month earlier. But within minutes of his arrival, Ethan is involved in a violent accident. He comes to in a hospital, with no ID, no cell phone, and no briefcase. The medical staff seems friendly enough, but something feels…off. As the days pass, Ethan’s investigation into the disappearance of his colleagues turns up more questions than answers.... View Details


Dark Matter: Reading the Bones
by Sheree R. Thomas (Author)

Dark Matter is the first and only series to bring together the works of black SF and fantasy writers. The first volume was featured in the "New York Times," which named it a Notable Book of the Year. View Details


Dark Matter: New Poems
by Robin Morgan (Author)

In this major new book of poems, her seventh, Robin Morgan rewards us with the award-winning mastery we've come to expect from her poetry. Her gaze is unflinching, her craft sharp, her mature voice rich with wry wit, survived pain, and her signature chord: an indomitable celebration of life. This powerful collection contains the now-famous poems Morgan reads in her TED Talk--viewed online more than a million times and translated into 24 languages. Dark Matter is an unforgettable book. View Details


Dark Matter
by Agustin Ramos (Author)

Dark Matter is a compilation of emotional complexity that dives into love, regret, and trauma. Expressed by a young poet who is trying to free his troubled mind. From personal experiences to figments of imagination. In doing this the writer tries to navigate his emotions and mind. Inspired by 2Pac, Frank Ocean, and Stanley Kubrick. These idols have helped the writer express himself artistically. View Details


The Punch Escrow
by Tal M. Klein (Author)

Dubbed the “next Ready Player One,” by former Warner Brothers President Greg Silverman, and now in film development at Lionsgate.

"Featuring themes similar to Blake Crouch’s Dark Matter, the dense sci-fi feel of a Michael Crichton thriller and clever Douglas Adams-like charm, the book posits an intriguing future that is both inviting and horrific." ―Brian Truitt, USA TODAY

It's the year 2147. Advancements in nanotechnology have enabled us to control aging. We’ve genetically engineered mosquitoes to feast on carbon fumes instead of blood, ending... View Details

Best Science Podcasts 2018

We have hand picked the best science podcasts for 2018. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

The Person You Become
Over the course of our lives, we shed parts of our old selves, embrace new ones, and redefine who we are. This hour, TED speakers explore ideas about the experiences that shape the person we become. Guests include aerobatics pilot and public speaker Janine Shepherd, writers Roxane Gay and Taiye Selasi, activist Jackson Bird, and fashion executive Kaustav Dey.
Now Playing: Science for the People

#478 She Has Her Mother's Laugh
What does heredity really mean? Carl Zimmer would argue it's more than your genes along. In "She Has Her Mother’s Laugh: The Power, Perversions, and Potential of Heredity", Zimmer covers the history of genetics and what kinship and heredity really mean when we're discovering how to alter our own DNA, and, potentially, the DNA of our children.