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Mystery Signal Could Be Dark Matter Hint In ISS Detector
astroengine writes Analysis of 41 billion cosmic rays striking the Alpha Magnetic Spectrometer particle detector aboard the International Space Station shows an unknown phenomena that is "consistent with a dark matter particle" known as a neutralino, researchers announced Thursday. Key to the hunt is the ratio of positrons to electrons and so far the evidence from AMS points in the direction of dark matter. The smoking gun scientists look for is a rise in the ratio of positrons to electrons, followed by a dramatic fall — the telltale sign of dark matter annihilating the Milky Way's halo, which lies beyond its central disk of stars and dust. However, "we have not found the definitive proof of dark matter," AMS lead researcher Samuel Ting, with the Massachusetts Institute of Technology and CERN in Switzerland, wrote in an email to Discovery News. "Whereas all the AMS results point in the right direction, we still need to measure how quickly the positron fraction falls off at the highest energies in order to rule out astrophysical sources such as pulsars." But still, this new finding is a tantalizing step in the dark matter direction.
>> the telltale sign of dark matter annihilating the Milky Way's halo
Sooooo when did dark matter become anti-matter? Or am I missing something?
Does this mean they'll find the gravioli next?
Strange things are afoot at the Circle-K.
Are we talking about the fountain of 511keV positron/electron annihilation photons from the galactic poles, or are we talking some exotic gammas from an Neutralino annihilation?
Inquiring minds want to know... :)
Truth isn't Truth - Guliani
Great job on the whole moving out of the domes thing; how's R. Daneel?
Truth isn't Truth - Guliani
the telltale sign of dark matter annihilating the Milky Way's halo
Is that supposed to be "annihilating in the Milky Way's halo"?
systemd is Roko's Basilisk.
Her mother Nut is the sky god, you're saying she can't visit?
Giving a name to "everything" we can't see and then finding evidence that there's something more is a bit curious.
Except it isn't a name for everything or even some general, broad category of unknowns. It started as a potential solution of a specific unknown, and expanded to cover a small number of other situations that were found to be explainable by a single, common theory.
What hasn't been "seen" yet is "dark".
There is a lot of unseen stuff that doesn't get the dark label. The same models that predict that dark matter is non-baryonic also show that that we only see about a quarter of normal matter our there. In that case, the normal matter we don't see is not a part of dark matter, but just unseen stuff.
The summary makes little sense, but I suspect this is because nothing was really found. Awake me when you will have some real news.
Dark matter simply means matter that is too small to be detected by what humans have so far developed to see, but which gravity study suggests should be there. Seventy years ago, Pluto was probably "dark matter". Giving a name to "everything" we can't see and then finding evidence that there's something more is a bit curious. What hasn't been "seen" yet is "dark". We will eat away at "dark" matter one snapshot at a time.
No, thats not correct. Dark matter is not matter that is "too small" to detect currently. Its matter that does not interact with electromagnetic radiation ( light, radio waves, gamma waves etc ) in any way, shape or form. We know its there from its gravitational interactions, that is correct. But it is not affected and does not affect electromagnetic radiation, or electric or magnetic fields. Its size is not the issue that makes it so difficult to detect.
That's why it's "dark," (pedantic AC corrections notwithstanding), but I would say its size is something that makes most dark matter candidates hard to detect. These particles are mostly predicted to be too massive for production at current accelerators.
.: Semper Absurda
Which would be the biggest news for physics: A discovered candidate for dark mattery or discovery of a particle predicted by supersymmetry? I thought evidence from the LHC was casting doubt on many supersymmetry theories? Also Samuel Ting is fairly old which is a shame because it might be unlikely he could live long enough to be one of those rare scientists who are awarded multiple Nobel Prizes.
The fact is that we have too little evidence to guide us, and we can all speculate to some extent. My favourite, based on nothing more than my own wishful thinking, really, is that dark matter consists of not just 1 kind of particle, but of a whole 'phylum' (to borrow a word from biology) of particles that interact with themselves much like the particles we know; there may be several phylums (or phyla, if you prefer). The reason I like the idea is simply that it allows me to fantasize about a kind of parallel universe that we can't see - even life; a sort of ghost universe. Wouldn't that be cool :-) ?
No, as other AC said, this is flat out wrong. Candidates like axions can interact with magnetic field and directly decay into photons, which is an EM interaction. Majorana fermions can still possess a toroidal moment which is extremely limiting to interacting with electromagnetism, but still allows it to interact. If particles were allowed to have a charge that is a small faction of the electron's charge, you could have very weak but difficult to observe electromagnetic interactions. Other particles could still interact through electromagnetism through loops in their Feynman diagram, which is rare but can happen, just like photon-photon scattering.
This not only discusses it, but has a link to the actual Phys Rev Letters paper. Jester (the blogger) thinks it may be a more mundane explanation, but still an interesting one.
http://resonaances.blogspot.co...