Anapole Dark Matter, Chiu Man Ho and Robert J. Scherrer, Vanderbilt University 2013.04.26: Rich Murray 2013.06.12 http://rmforall.blogspot.com/2013/06/anapole-dark-matter-chiu-man-ho-and.html
Funny how whole new fields of physics pop up like magic weeds -- Majorana fermion anapoles may be the dark matter that is 20-25% of all energy-matter in our bubble, while stars and photons and us are made of ordinary matter, the last 13,680 million years. They would only interact more and more with ordinary matter at higher and higher velocities -- would this put a brake on vehicles reaching near the speed of light? Could some kind of ram jet operate to scoop them up and produce thrust? How might they interact with black holes? How long before first detection, the first telescope, the first controlled beam, the first whachamacallit....? http://news.vanderbilt.edu/2013/06/dark-matter/ http://www.sci-news.com/physics/article01146-dark-matter-majorana-fermion.html http://arxiv.org/pdf/1211.0503v3.pdf arXiv:1211.0503v3 [hep-ph] 26 Apr 2013 Anapole Dark Matter, Chiu Man Ho and Robert J. Scherrer, Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37235 We consider dark matter (DM) that interacts with ordinary matter exclusively through an electromagnetic anapole, which is the only allowed electromagnetic form factor for Majorana fermions. We show that unlike DM particles with an electric or magnetic dipole moment, anapole dark matter particles annihilate exclusively into fermions via purely p-wave interactions, while tree-level annihilations into photons are forbidden. We calculate the anapole moment needed to produce a thermal relic abundance in agreement with cosmological observations, and show that it is consistent with current XENON100 detection limits on the DM-nucleus cross-section for all masses, while lying just below the detection threshold for a mass 30 - 40 GeV.
