EVIDENCE for the Higgs boson could be pouring down upon us from deep space. If so, an orbiting space telescope could upstage the Large Hadron Collider in the search for the elusive particle.
was launched last year to detect gamma rays. One expected source of gamma rays is the mutual annihilation of dark matter particles in our galaxy. While the nature of dark matter 鈥� which makes up 90 per cent of the matter in the universe 鈥� is unknown, physicists think it is made of weakly interacting massive particles, or WIMPs.
WIMPs appear in many theories. of the University of California, Irvine, and colleagues analysed WIMPs that show up in so-called Randall-Sundrum models of space-time. These models propose a fourth dimension to space that is curled up so small as to be undetectable. Gravity leaks into this extra dimension, explaining why it is orders of magnitude weaker than the other fundamental forces of nature.
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The dark matter particles in such models can annihilate and produce a slew of secondary particles. Two WIMPs, each with a mass of between 50 and 200 gigaelectronvolts, can annihilate into two massless gamma-ray photons, the energy of each equalling the mass of one WIMP. Alternatively, the WIMPs can produce one photon and one massive particle.
According to the researchers, one such massive particle could be the Higgs boson 鈥� the particle thought to endow all elementary particles with mass. 鈥淚f there is a strong connection between the physics of dark matter and the physics of mass generation, those dark matter particles probably like to interact with the Higgs boson,鈥� says Tait ().
鈥淭here might be a connection between the physics of dark matter and that of mass generation鈥�
If this was the case, a study of the sky 鈥� say in the direction of the galactic centre, where dark matter particles are supposed to be concentrated 鈥� should show gamma rays peaking at certain energies. The standard expectation of dark matter is that you鈥檒l see one single peak, says Tait. 鈥淲e are predicting that there may be an entire forest.鈥�
If FERMI sees these telltale signatures anytime soon, then in theory it will have sighted the Higgs before the LHC, which is still a few years from any such discovery. 鈥淔ERMI has very good prospects of discovering the Higgs if this model is true,鈥� says Tait.
The gamma-ray peaks could also be detected by ground-based gamma-ray telescopes such as in southern Arizona or .
of Fermilab in Batavia, Illinois, says the model used by Tait鈥檚 team is exotic but not implausible. 鈥淔ERMI is the kind of experiment you would want to use to look for this kind of signature,鈥� says Hooper. 鈥淚f they got lucky, and this kind of dark matter candidate exists, then they could measure the masses of both the dark matter and the Higgs.鈥�
The FERMI telescope has already collected some gamma-ray measurements from the centre of the Milky Way but so far it has only been used to put limits on how much dark matter is out there, according to of the FERMI collaboration at the SLAC National Accelerator Laboratory in Menlo Park, California. 鈥淲e are only starting to untangle what鈥檚 going on.鈥�
