Synopsis: Looking under the Antarctic ice for evidence of dark matter

Detectors buried beneath the Antarctic ice place stringent limits on the presence of dark matter particles, called neutralinos, in the sun.
Synopsis figure

In the search for dark matter, among the most interesting candidates is the neutralino, a neutral particle, predicted in supersymmetric extensions of the standard model, which interacts only weakly with other matter. Since the neutralino is expected to be stable, it may be possible to find particles that are relics of the early universe.

Theorists have predicted that the sun’s gravity can trap neutralinos, which could collect in its center and then annihilate each other. The standard-model particles created by these annihilations could subsequently decay, producing high-energy neutrinos that could escape from the sun and be detected on earth. Based on searches for these neutrinos, the IceCube Collaboration has now reported in Physical Review Letters new limits on neutralino annihilations in the sun.

The IceCube neutrino detector is located between 1.5 and 2.5km beneath the Antarctic ice, to reduce background events from cosmic rays. When muon neutrinos from the sun interact with the ice, they create relativistic charged particles (muons and showers of hadrons) that produce Cherenkov light, which is picked up by the detector. In an experiment lasting more than three months, no excess of neutrinos from the direction of the sun was detected. The experimentalists have therefore placed stringent limits on neutralino annihilations in the sun—a factor of 6 improvement over some previous limits—and from these, limits on the cross section for neutralino-proton interactions for neutralinos with masses above 250GeV. These results narrow the possibilities for dark matter. – Stanley Brown


More Announcements »

Subject Areas

Particles and FieldsAstrophysicsCosmology

Previous Synopsis


Groovy nanowires

Read More »

Next Synopsis

Related Articles

Viewpoint: Unlocking the Hidden Information in Starlight

Viewpoint: Unlocking the Hidden Information in Starlight

Quantum metrology shows that it is always possible to estimate the separation of two stars, no matter how close together they are. Read More »

Synopsis: Emptiness Constrains the Universe

Synopsis: Emptiness Constrains the Universe

The distribution of galaxies around regions of relatively empty space can be used to constrain cosmological parameters. Read More »

Synopsis: Pentaquark Discovery Confirmed
Particles and Fields

Synopsis: Pentaquark Discovery Confirmed

New results from the LHCb experiment confirm the 2015 discovery that quarks can combine into groups of five. Read More »

More Articles