Dark Matter Possibly Discovered by ISS Experiment

The team running the AMS experiment plans to make a big announcement soon

By on February 18th, 2013 14:31 GMT

The search for dark matter may be getting closer to an end as researchers operating the Alpha Magnetic Spectrometer (AMS) instrument, mounted to the side of the ISS, are teasing the scientific community with clues to a big announcement coming in a couple of weeks.

The team isn't ready to make the big announcement just yet, but Nobel Prize winner Samuel Ting, AMS' principal investigator, says a paper is to be published soon and that what's revealed inside will not be minor.

In a conference during the American Association for the Advancement of Science, he gave some strong hints that something big is about to be announced, but would not confirm anything.

AMS is looking to prove the existence of dark matter by looking for an excess in positrons, the electron's antimatter counterpart, at a particular energy level.

Dark matter is thought to make up some 84 percent of the matter in the universe, the rest being regular matter, the stuff we, the planets, the stars and pretty much everything else we know of is made up of.

Dark matter also constitutes some 23 percent of the energy in the Universe, with four percent made up of regular matter and the rest being the even more mysterious dark energy.

By its very nature, dark matter doesn't interact with regular matter, except via gravity. Since gravity interactions are so weak, trying to detect dark matter this way is close to impossible with today's technology.

The most widely accepted theory on dark matter says that it's made up of WIMPS (weakly interacting massive particles), particles that are their own antimatter counterparts.

This means that when two WIMPS meet, they annihilate each other, resulting in an electron-positron pair at a specific energy level.

This energy level depends on the mass of the WIMPS, which we don't know, so scientists don't know where to look for this excess, but they know what it will look like, a sharp rise in the number of positrons followed by an even sharper drop.

If an excess of positrons is found, it would be a big step towards actually detecting dark matter since this excess can't be explained through other known natural phenomena, especially if this excess is omnidirectional, i.e. it's coming from everywhere in the universe, not from a specific source, like a pulsar.

It will be indirect proof, but the best one we're likely to get any time soon. The AMS has been operating on the ISS for almost two years now and has amassed data in 25 billion particle events so far, eight billion of which are electrons and positrons.

The first paper describing the findings of the experiment is coming in a couple of weeks, until then the people involved aren't talking. But they are sending clear hints that they found something.

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