Looking for Dark Matter with Gravitational Waves
22 Jun 2020 17:53:46 UTC
Topic 222903
(moderation:
Physicists are building a prototype tabletop detector to capture gravitational waves at higher frequencies than LIGO can and to possibly spot waves from annihilating axions.
https://physics.aps.org/articles/v13/100
The LHC at CERN has placed
)
The LHC at CERN has placed some interesting limits on Dark Matter interaction with the Higgs boson. Mind you the experimental signature is a 'negative' one : a missing energy channel, rather like neutrinos.
"The data show no excess of such characteristic events over the expected background. ATLAS concluded at a 95% confidence level that no more than 13% of Higgs bosons produced in the LHC could transform into invisible particles. These findings place the strongest limits so far on Higgs transformations to such invisible particles."
Now given that the Higgs is supposed to define the mass of all particles, Dark Matter candidates included, then this is a significant upper bound. But this still leaves open the possibility that Dark Matter particles are very heavy and thus out of the energy range that the LHC provides.
This Dark Matter stuff is most elusive, as by definition it fails to interact with electromagnetic fields. Personally I reckon Dark Matter is a product of a wrong assumption ( or several ) somewhere in our thinking.
Cheers, Mike.
I have made this letter longer than usual because I lack the time to make it shorter ...
... and my other CPU is a Ryzen 5950X :-) Blaise Pascal
Maybe if I run a few ATLAS,
)
Maybe if I run a few ATLAS, they will come up with a different answer.
Thanks.
I believe that Dark Matter is
)
I believe that Dark Matter is not made up from particles, such as WIMPS, Axions, Dirac or Majorana neutrinos. After all all ordinary matter is made up from protons, neutrons and electrons. Electrons do not have constituents, but protons and neutrons are made up from quarks, that nobody has ever seen as free particles. Three quarks make a neutron or proton, two quarks a meson. So even ordinary matter is made up from something which we cannot detect directly. We know only their symmetries, which are pure mathematics.
Tullio
You have probably seen this
)
You have probably seen this by now, but it is relevant.
https://www.bbc.com/news/science-environment-53085260
I think they will be starting a more sensitive experiment early next year, delayed a bit by the virus.
There are more experiments in
)
There are more experiments in preparation, CAST at CERN, DUNE in USA, Super Kamiokande in Japan. Reading the CERN Courier I learned that Axions are a consequence of a new U(1) gauge symmetry which causes a very small CP violation in quantum chromodynamics. From what I remember from an online course on the Higgs boson by the University of Edinburgh the U(1) symmetry group is the symmetry of the electromagnetic interacion, SU(2) is the symmetry group of the weak interaction and SU(3) is the symmetry of the strong interaction. But all experiments so far have given no clear results.
Tullio
tullio wrote: But all
)
OK, since you are following the literature, and more importantly understand it, I will await your input on what they find.
Thanks for the update.