Last week, the world took note as CERN announced that it may have found the Higgs boson - or at the very least, a Higgs-boson-like particle. But now, some scientists have suggested that CERN's experimental results may be the result of impostor particles, albeit Higgs-like impostors.
Scientists Ian Low (from the High Energy Physics Division at Argonne National Laboratory and the Department of Physics and Astronomy at Northwestern University), Joseph Lykken (Fermi National Accelerator Laboratory), and Gabe Shaughnessy (Department of Physics at the University of Wisconsin, Madison) self-archived a scientific paper on arXiv - the Cornell University Library preprint/pre-publish service for mathematics and physics research papers - on this very topic. This preprint describes alternative possibilities to the recent discovery at CERN, which shows a particle that well fits the Standard Model of particle physics as the Higgs boson.
We're about to get into some complicated particle physics here, so bear with us.
The preprint explains that the particle discovery at CERN could be either a generic Higgs doublet, a Higgs triplet, a mixture of particles including the Higgs and another particle, or of course, the Higgs boson as the Standard Model predicts. In the Standard Model, the Higgs has a spin - a type of truly "intrinsical" (unexplained but clearly existing) property that accounts for the magnetic properties and the apparent angular momentum of a particle, and is related to the particle's electric charge and rest mass - value of zero.
In the Standard Model, the Higgs particle is a singlet. However, in the case of the potential impostor particles, a Higgs doublet is a Higgs particle that can have a spin with allowed values of either -1/2 or 1/2. And a Higgs triplet can have three values with a total spin value of 1. Singlets, doublets, and triplets all derive from an algebraic structure called special unitary groups. Findings of anything but the Higgs singlet could either prove the Minimal Supersymmetric Standard Model - an extension to the Standard Model--or an alternative model altogether.
The scientists explain that both the predicted Higgs boson itself and the predicted Higgs triplet is within one sigma of the experimental measured value (to learn more about sigma values, visit CERN's glossary of terms page and scroll to "Standard deviation/Sigma"). Technology Review points out that in one case the triplet is even favored in the "predicted scenario," which is meant to match the measured data to theoretical models.
Whew! Did you get all that? Although it's possible that CERN scientists haven't yet discovered the long-sought-after Higgs boson and instead found an impostor, it is still more likely that this newly discovered particle is indeed the Higgs boson. As it turns out, the measured values still favor the theoretical models of the Higgs boson in the Standard Model of particle physics. However, the close values of these other theoretical possibilities should not yet be ruled out, given the significance of this discovery.
In any case, the discovery of either a new, unexpected particle or the Higgs boson would prove to be detrimental to our current understanding of nature. Every piece, big or small, that we collect brings us closer and closer to putting together the puzzle of the universe.
If you'd like to learn more about the alternatives to the Higgs--and you just happen to have a degree in particle physics - hop on over to arXiv and take a seat.