Signal in LHC may not be standard model Higgs boson after all

Posted Jul 11, 2012 by JohnThomas Didymus
A new paper by Ian Low and colleagues at Cornell University casts doubt on the identity of the particle CERN scientists announced as consistent with the "standard model Higgs boson." The study says the particle may not be the standard Higgs after all.
Overview of the first elements of the huge magnet of the CMS experimental site.
Overview of the first elements of the huge magnet of the CMS experimental site.
After a quest that spanned several decades, CERN scientists recently celebrated the disccovery of a new particle they believe is the Higgs. But Cornell University scientists Ian Low, Joseph Lykken and Gabe Shaughnessy, in a new paper titled, "Have we observed the Higgs(imposter)?" have called for caution. While the scientists admit that "The new resonance discovered by the ATLAS and CMS experiments at the CERN Large Hadron Collider (LHC) could be the long-sought Higgs boson of the Standard Model," the researchers point out that it is still uncertain that it is the "standard model Higgs."
Distinguishing between a standard model Higgs boson and a more exotic variety of the Higgs boson is important because the "standard model Higgs" is required to fill in the gaps in the Standard Model of particle physics that is the most widely accepted theoretical model of the physical universe. A new exotic particle that exhibits properties similar to the standard Higgs but also has properties not predicted by or inconsistent with the "Standard Model" may lead to extensive review of the Standard Model and a new theoretical picture of the universe that invalidates some of the premises on which the current theoretic model is based.
Apart from the possibility that the particle detected may be an exotic variant of the standard model Higgs, there is another possibility that what was detected is a mix of variants of the plain Higgs. According to the Cornell study: "We show that current LHC data already strongly disfavor both the dilatonic and non-dilatonic singlet imposters. On the other hand, a generic Higgs doublet and a triplet imposter give equally good fits to the measured event rates of the newly observed scalar resonance."
What the technical language means simply is that what CERN scientists discovered could actually be a single particle or a mix of particles that are different versions of the plain standard model Higgs.
According to, the study says that the signatures predicted for the Higgs boson and the "triplet imposter are both within one sigma of the measured value. And by one measure, the CERN data even favours the triplet imposter."
The scientists, therefore, called for caution in evaluating and interpreting the available evidence, saying, "currently the uncertainties in these quantities are too large to make a definitive statement."
After the initial excitement and media publicity, CERN scientists are now taking a closer look at the data to see if it matches what is expected of the standard model Higgs boson or if they have discovered a new exotic particle that will ultimately challenge the currently accepted standard model worldview.
According to the Daily Mail, one of finds that have raised concerns about the true identity of the new particle is the fact that while it has so far behaved like the standard model Higgs, it is significantly lighter than expected. According experts, this raises the possiblity that there may be more than one Higgs boson.
But discovery of a more "exotic variety" of the Higgs boson may actually open up new exciting fields of inquiry for research scientists and lead either to extensive review of the current theories of particle physics are a fine tuning of the already existing theories. This explains why scientists will be far from disappointed if it is finally demonstrated that the new particle is not the standard Higgs.
According to, Harvey Newman, a high-energy physicist at the California Institute of Technology, and member of the Compact Muon Solenoid (CMS) experiment, said that finding a particle more exotic that the plain standard model Higgs would actually be "one of he most exciting things that can happen."
Digital Journal reports that scientists sometimes employ the analogy of sticky molasses or a snowfield to describe the Higgs field corresponding to the particle. The Higgs boson is conceived of as associated with an energy field through which particles travel.The effect of the Higgs field on particles is likened to the effect on persons passing through a "snowfield" depending on whether they are wearing "skis, snowshoes or just shoes."
According to Life's Little Mysteries, John Gunion, physicist at the University of California, compares the Higgs field to a cosmic swimming pool in which everything is swimming. According Gunion, "Particles that interact strongly with the Higgs field, 'like a heavyset man swimming with his clothes on' are heavier than particles that breeze through the pool 'like an Olympic swimmer in a wetsuit.'"
However, the picture presented in the Standard Model may be an oversimplified model of how things work. According to Life's Little Mysteries, Newman explains that the standard model appears incomplete because so far it has failed to account for dark matter that makes up 84 percent of the matter in the entire universe. The Standard Model also fails to explain gravity, and treats matter and anti-mater as though they were symmetrical and thus fails to account for why we live in a universe that has far more matter than antimatter. Newman also explains that the Standard Model appears to fail at the higher energies that existed soon after the big bang. According to Newman, the Standard Model is "simple and powerful, but we know it can't be the complete theory." He said: "Newton's laws are beautifully simple and describe so much, but we know it's not the fundamental theory, just the low-energy limit of a more fundamental theory. It's the same thing here. We know there must be a more fundamental theory than the Standard Model."
The theory that finally incorporates the Standard Model into a more comprehensive picture of the universe will possibly look more like a theory called supersymmetry or SUSY. SUSY is more comprehensive because it appears to predict the existence of dark matter and explains particle interactions at very high energies. The theory complicates the simplicity of the Standard Model by proposing at least five Higgs fields each with a Higgs-like boson.
Scientists believe that the signal detected by the LHC could be one of the "Higgs-like" bosons the supersymmetry theory predicts. That is, the particle may not be a standard model Higgs, but a SUSY Higgs or some other even more exotic Higgs that current theories do not account for.
According to Life's Little Mysteries, if the particle turns out an even more exotic Higgs than the standard model and SUSY Higgs, that would be a moment of great excitement for physicists because it will be the "first discovery of physics beyond the Standard Model."