http://physicsworld.com/cws/article/news/2015/jan/12/new-calculations-support-dark-matter-discovery-by-dama-say-physicists
In the article it says it looks for seasonal variations as the earth moved through the Milky Way dark matter halo .. Err what?
all i can guess at is that the axial tilt results in the particle having to traverse a greater distance underground during winter than summer.
Dropbear said:
http://physicsworld.com/cws/article/news/2015/jan/12/new-calculations-support-dark-matter-discovery-by-dama-say-physicists
In the article it says it looks for seasonal variations as the earth moved through the Milky Way dark matter halo .. Err what?
No idea why an annual variation would suggest the existence of dark matter particles. But they might.
> It proposes that dark matter interacts with ordinary matter not via one of the four known fundamental forces but instead through a fifth force mediated by an axion-like particle.
If Axions exit then they should be coming from the Sun. Searches for Axions coming from the Sun didn’t find any.
> However, unlike the Higgs boson, the quantum state of the new particle changes when its spatial co-ordinates are reversed, a property that earns it the title “pseudoscalar”.
Thanks for explaining that. So “scalar particles” are their own antiparticle whereas “pseudoscalar particles” have a distinct antiparticle. I hadn’t known that.
> The team has also shown that the pseudoscalar interaction could explain an excess of gamma rays observed at the centre of the galaxy in terms of annihilating dark-matter particles.
That is interesting. It’s already been shown that this gamma ray excess is too weak to have been caused by dark matter particles, WIMPS, but their idea that a pseudoscalar interacts much more weakly with ordinary matter than a more normal WIMP (because of the spin of the detector nucleons) deserves consideration.
> “I think it is very interesting that these authors can still find room to wiggle while limiting themselves to nuclear-recoil interactions.”
I heartily agree. I should add that experiments that have claimed to have detect WIMPS have in the past disagreed massively with each other.