Name Comes Later: AMS finds Dark Matter?

The Alpha Magnetic Spectrometer (AMS-02) is a state-of-the-art particle physics detector constructed, tested and operated by an international team composed of 60 institutes from 16 countries and organized under United States Department of Energy (DOE) sponsorship. The AMS-02 will use the unique environment of space to advance knowledge of the universe and lead to the understanding of the universe's origin by searching for antimatter, dark matter and measuring cosmic rays. (Photo credit: Wikipedia)

100 years ago, Hess became the discoverer of cosmic rays, or very high energy particles whose origin comes from beyond our own Solar System.

These cosmic rays have a huge energy range, ranging from non-relativistic speeds all the way up to around a whopping 10²⁰ electron-Volts, or about a factor of 10,000,000 greater than the LHC — even at maximum energy after the upgrade-in-progress — will ever achieve. There are also much smaller numbers of cosmic-ray electrons, followed by trace amounts of cosmic-ray antimatter, including positrons and anti-protons.

There are tons of astrophysical sources for cosmic rays, both in our galaxy and beyond.

Some cosmic rays show a clear origin from point sources, such as the pulsar at the center of the crab nebula, below.

The vast majority of them are still of an unknown origin, although many ideas abound. The antimatter is no problem at all; we’re

That’s the cosmic ray side of things.

At the same time, there’s another puzzle in the Universe: the dark matter puzzle.

That can come in any form that the mass of dark matter allows: photons, electron/positron pairs, proton/anti-proton pairs, etc.

Well, enter the latest attempt at indirect detection of dark matter, the Alpha Magnetic Spectrometer.

Launched aboard the Space Shuttle Endeavour’s final mission, the Alpha Magnetic Spectrometer (AMS) was attached to the International Space Station, where it’s quickly become the most advanced, sophisticated and prolific cosmic ray detector of all-time.

With over 31 billion cosmic ray particle detections (and counting), AMS is giving us an unprecedented amount of data to study cosmic rays.

This is what AMS does, and over their first 25 billion cosmic ray detections, they’ve detected about 400,000 positrons of varying energies.

The key to telling them apart is to look at the spectrum of positrons, along with the corresponding spectrum of electrons and the locations where these cosmic rays originate.

A dark matter signal would show the same “bump-and-drop-off” in the electron spectrum as in the positron spectrum, something that Fermi has reported to not exist all the way up to energies of 1 TeV.

The AMS data shows unprecedented precision in the measurement of the antimatter cosmic ray energy spectrum, and there’s plenty to be learned from this.

Just not about dark matter, at least, based on what it’s seen so far.

To reiterate, based on what AMS has presented, there is nothing to suggest that they have detected any evidence whatsoever for particle dark matter.