ITN: Dark Matter Discovered ?

[CraigS]

In the News:

Physics experiment suggests existence of new particle

The results of a high-profile Fermilab physics experiment involving a University of Michigan professor appear to confirm strange 20-year-old findings that poke holes in the standard model, suggesting the existence of a new elementary particle: a fourth flavor of neutrino.

Man, this one's go it all ! … symmetry broken ! ..

The new results go further to describe a violation of a fundamental symmetry of the universe asserting that particles of antimatter behave in the same way as their matter counterparts.

But wait, there's more !… a dark matter candidate ! …

The three known types of neutrino interact with matter primarily through the weak nuclear force, which makes them difficult to detect. It is hypothesized that this fourth flavor would not interact through the weak force, making it even harder to find.
..
"Physicists and astronomers are looking for sterile neutrinos because they could explain some or even all of the dark matter of the universe"

Very interesting. They conclude with a cautionary note that they need more data (which makes a lot of sense). This is great research. Good on them.
Have to keep track of this one.

Cheers

[Robh (Rob)]

And yet an earlier but related story (link on same web page) concludes the Fermilab MINOS results don't support the existence of a fourth, sterile neutrino. Interesting times!

Regards, Rob

[CraigS]

Rob;
Would that be the Feb 16, 2010 report ?

If so, it says:

The MINOS results also disfavor the existence of a fourth, sterile neutrino. Past analyses have shown that if muon neutrinos are oscillating into sterile neutrinos, only 68 percent of the disappearing neutrinos can do so. The new MINOS analysis shrinks that percentage to 50 percent, and future MINOS data are expected to reduce it further.

I'm not sure I'd interpret this wording as confirming the non-existance of the fourth sterile neutrino .. ??…

Which report were you referring to ? I may not have the one you mean.

Cheers

[Robh (Rob)]

Just making the point that neither experiment confirms anything one way or the other. It will be interesting to see which way it heads.

Rob.

[CraigS]

Oh well ..

Looks like they've discovered an instance of 'neutrino flavor oscillation'.

The challenge now is to confirm it by replicating the results over longer periods of time.

Then its a matter for the theory to explain it all, I guess.

Its the closest report I've seen so far from a reputable source, though. Pity I can't get hold of the report (& cut the jouno stuff out of it all). Mind you, the abstract is very particle-physicist specific.

Time will tell, eh ?

Cheers