New detectors allow search for lightweight dark matter particles

September 8, 2015
By carefully re-engineering a detector for heavy dark matter particles, so-called WIMPS, the CRESST collaboration succeeded in improving the detector to measure lightweight dark matter particles with masses in the range of a proton mass. Credit: Max Planck Institute for Physics

The Earth, planets, stars, and galaxies form only the visible portion of the matter in the universe. Greater by far is the share accounted for by invisible "dark matter". Scientists have searched for the particles of dark matter in numerous experiments - so far, in vain. With the CRESST experiment, now the search radius can be considerably expanded: The CRESST detectors are being overhauled and are then able to detect particles whose mass lies below the current measurement range. As a consequence, the chance of tracking dark matter down goes up.

Theoretical models and astrophysical observations leave hardly any doubt that exists: Its share is five times more than all visible material. "So far a likely candidate for the was thought to be a heavy particle, the so-called WIMP," explains Dr. Federica Petricca, a researcher at the Max Planck Institute for Physics and spokesperson of the CRESST experiment (Cryogenic Rare Event Search with Superconducting Thermometers). "Most current experiments therefore probe a measurement range between 10 and 1000 GeV/c^2."

The current lower limit of 10 GeV/c^2 (GeV: gigaelectronvolt; c: speed of light) roughly corresponds to the mass of a carbon atom. However, recently various new have been developed with the potential of solving long-standing problems, like the difference between the simulated and the observed dark matter profile in galaxies. Several of theses models hint towards below the mass of the traditional WIMP.

Measurement record for light particles of dark matter

Now CRESST has achieved an important step toward tracking down these potential "lightweights": In a long-term experiment with one detector, the researchers achieved an energy threshold of 307 eV. "With that, this detector is best suited for measurements between 0.5 and 4 GeV/c^2, improving its sensitivity by 100 times," says Dr. Jean-Come Lanfranchi, scientist at the Chair for Experimental and Astroparticle Physics at Technical University of Munich.

"We now can detect particles that are considerably lighter than WIMPs - for example dark matter particles with a weight comparable to a proton, which has a mass of 0.94 GeV/c^2", adds Petricca.

On the basis of the newly gained insights, the scientists will now equip the experiment with the novel detectors. The next measurement cycle of CRESST is expected to begin at the end of 2015 and last for one to two years.

Experimental setup

The central part of all CRESST detectors is a crystal of calcium tungstate. When a particle hits one of the three crystal atoms (calcium, tungsten, and oxygen), the detectors simultaneously measure energy and light signals from the collision that deliver information about the nature of the impinging particle.

In order to catch even the smallest possible temperature and light signals, the detector modules are cooled to near absolute zero (-273.15 degrees C). To eliminate disturbing background events, the CRESST scientists employ - for one thing - materials with little natural radioactivity. In addition, the experiment stands in the world's largest underground laboratory, in the Italian mountain Gran Sasso, and thus is largely shielded from cosmic rays.

What's new?

  • CRESST will work in the future with smaller and - compared to commercially manufactured materials - ultrapure crystals. With the reduced size a lower energy threshold can be achieved. These crystals are grown at the Technical University of Munich and exhibit extremely low innate radioactivity, making the experiment more sensitive.
  • The original bronze crystal holdings have been replaced with calcium tungstate. With this, the number of undesired effects due to natural radioactivity on the metal surfaces can be strongly reduced.
  • The precision of the light detector has been optimized - collisions of already known particles can be more clearly distinguished from collisions of dark matter particles.

Explore further: Scientists crank up the voltage, create better dark-matter search

More information: Results on light dark matter particles with a low threshold CRESST-II detector, The European Physical Journal C, Sept 2015. arxiv.org/abs/1509.01515

Related Stories

CRESST team finds new 'evidence' of dark matter

September 8, 2011

(PhysOrg.com) -- In the never ending search for proof that dark matter really exists, new findings have emerged from a team working under a big mountain in Italy. The group, from the Max Planck Institute in Germany, have ...

A detector shines in search for dark matter

August 20, 2015

Results of the XENON100 experiment are a bright spot in the search for dark matter. The team of international scientists involved in the project demonstrated the sensitivity of their detector and recorded results that challenge ...

Recommended for you

Flexible ferroelectrics bring two material worlds together

January 17, 2017

Until recently, "flexible ferroelectrics" could have been thought of as the same type of oxymoronic phrase. However, thanks to a new discovery by the U.S. Department of Energy's (DOE) Argonne National Laboratory in collaboration ...

First-ever X-ray image capture of material defect process

January 17, 2017

From blacksmiths forging iron to artisans blowing glass, humans have for centuries been changing the properties of materials to build better tools – from iron horseshoes and swords to glass jars and medicine vials.

Theory lends transparency to how glass breaks

January 16, 2017

Over time, when a metallic glass is put under stress, its atoms will shift, slide and ultimately form bands that leave the material more prone to breaking. Rice University scientists have developed new computational methods ...

A novel way to put flame retardant in a lithium ion battery

January 16, 2017

(Phys.org)—A team of researchers at Stanford University has found a novel way to introduce flame retardant into a lithium ion battery to prevent fires from occurring. In their paper published in the journal Science Advances, ...

19 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

liquidspacetime
1 / 5 (4) Sep 08, 2015
Particles of matter move through and displace the dark matter, including 'particles' as large as galaxies and galaxy clusters.

'The Milky Way's dark matter halo appears to be lopsided'
http://arxiv.org/abs/0903.3802

"the emerging picture of the dark matter halo of the Milky Way is dominantly lopsided in nature."

The Milky Way's halo is not a clump of dark matter traveling along with the Milky Way. The Milky Way's halo is lopsided due to the matter in the Milky Way moving through and displacing the dark matter, analogous to a submarine moving through and displacing the water.

The Milky Way's halo is the state of displacement of the dark matter.

The Milky Way moves through and curves spacetime.

The Milky Way's halo is curved spacetime.

The state of displacement of the dark matter is curved spacetime.

The state of displacement of the dark matter *is* gravity.
vlisivka
1 / 5 (4) Sep 08, 2015
It is time to accept that something is weaved by electromagnetic waves. I mean, we are surrounded by something like water or gas but at much lower level. It is already confirmed by Voyager space probes that propagation of electromagnetic waves *depends* on direction (search for magnetic foam or bubbles discovered by Voyager's).
Iourii Gribov
1 / 5 (1) Sep 08, 2015
My opinion: the CRESST will not detect DM! Why? See recently proposed alternative method for generation [1] (and detection [3]) of elementary DM particles via collisions between elementary antiparticles (e+,e+), (p-,p-), (p-,e+) in colliders." in: http://vixra.org/...9v2.pdf.
The DM particles are exactly DARK PROTONS (E=1GeV), DARK ELECTRONS (E=0,5MeV), etc., predicted in my united theory of DM, Ordinary Matter (OM) and Antimatter (OAM), etc. of the Periodic Waveguided Multiverse (PWM) [2]. Pairs of DM/OAM particles like (DM-electron/positron), (dark proton/antiproton) etc. could be created only in collision between antiparticles. DM can be detected also only using ANTIPARTCLES - mediators between DE and OM [3]. See corresponding cosmological application in http://www.resear...Trigger.
Iourii Gribov
1 / 5 (1) Sep 08, 2015
I am sorry, see corresponding cosmological applications (for the text above) in: (a) Gravitationally neutral Universe hypothesis: is our galactic group in the middle of the Universe-Ball? http://www.resear...se-Ball. S.A. Trigger, I.A. Gribov, A.A. Roukhadze-.(b) JEANS INSTABILITY AND ANTI-SCREENING IN GRAVITATIONAL-ANTIGRAVITATIONAL MODEL OF
UNIVERSE I. Gribov, S.A. Trigger. http://arxiv.org/...7122.pdf
Iourii Gribov
1 / 5 (1) Sep 08, 2015
Please, see the alternative "A new simple method for generation (and detection of elementary DM particles via collisions between elementary antiparticles" in: http://vixra.org/...09v2.pdf

docile
Sep 08, 2015
This comment has been removed by a moderator.
Seeker2
3 / 5 (2) Sep 09, 2015
"Theoretical models and astrophysical observations leave hardly any doubt that dark matter exists: Its share is five times more than all visible material."

Theory problem? Seems likely gravity emerges from a difference in pressure between different regions of spacetime, something like entropic gravity. Since we associate gravity with matter, this implies matter is a similar difference, only on a quantum scale. On these scales differences can take only quantized values. These differences are stored as energy. But spacetime differences occur on galactic scales. On macro scales everything I know of has variability, including the pressure of spacetime which appears as dark energy. On micro scales everything has uncertainty. So life goes. Strange because we don't perceive differences in spacetime pressure within our galaxy. Probably because we can't measure the vacuum with enough resolution. Maybe someday.
Seeker2
not rated yet Sep 09, 2015
Per http://arstechnic...ynamics/
what we would commonly call gravity—becomes, as Verlinde describes it, an entropic force due to the different informational densities between the two regions.

So what Verlinde calls informational densities I call pressure densities in spacetime. Sort of like one of Maxwell's demons.
docile
Sep 09, 2015
This comment has been removed by a moderator.
docile
Sep 09, 2015
This comment has been removed by a moderator.
docile
Sep 09, 2015
This comment has been removed by a moderator.
SnowballSolarSystem _SSS_
3 / 5 (2) Sep 11, 2015
I suggest that the systematic elimination of a growing number of DM candidates is closer to the definition of 'a wild goose chase' than to 'scientific method'. I fear Einstein would be wringing his hands with shame for the scientific community.
docile
Sep 11, 2015
This comment has been removed by a moderator.
docile
Sep 11, 2015
This comment has been removed by a moderator.
docile
Sep 11, 2015
This comment has been removed by a moderator.
docile
Sep 11, 2015
This comment has been removed by a moderator.
thaken
not rated yet Sep 12, 2015
It is nice to read come computations of dark matter, since this entity is collected within every center of galaxies. Able to manipulate the multi dimensions of dark energy creating, our galaxies of indigestible partials that we exist in. There is more proof of how the universe works, space time does not react with each other, dark energy has no concept of time, so it must expand, and dark matter feeds off dark energy. Collecting antimatter into its mass and repelling our opposite elements of the periodical chart out into space.
mytwocts
3 / 5 (4) Sep 12, 2015
There is no dark matter, nor dark energy taken from the comics books. The vacuum of space does not mean empty space. Empty space does not exits.

So 1) space is not empty and 2) space is dark.
That is, either you are an adept of DM or of DE or both.
Myself, I am not as convinced of these concepts as you appear to be, but I lack a viable alternative ;-).
sinta
1 / 5 (1) Sep 14, 2015
check our website, maybe there's some helpful information for you. Nanodiamond technologies nanodiamond.technology

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.