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CERN | Geneva | Switzerland

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New boson could pave the way towards new discoveries

After the spectacular results reported yesterday at CERN on the discovery of a new boson, the largest particle physics conference of the year started today in Melbourne. Such announcement put the bar high for all the speakers.

As many people have pointed out already, it is still early to call the new boson a “Higgs boson” although the odds are really high. First we must check that it behaves exactly like the Higgs boson. Is it produced as often as the Standard Model predicts, and does it decay in the same proportions as expected? Verifying these properties with the highest accuracy will be the main task in the coming months and years. It’s not that physicists are compulsive about precision, but this is exactly where we might find the opening to the “secret passage”.

Theorists like Peter Higgs, François Englert and Robert Brout in 1964 showed us the way when they postulated the existence of the Higgs boson and Higgs mechanism. Today still, theorists are trying to guide the experimentalists in the right direction.

All theorists today agree that our current theoretical model has its limits. The Standard Model appears to be to the world of particle physics what the four basic operations are to mathematics. Most daily tasks are achieved using only additions, subtractions, multiplications and divisions. But we all know that there is more to mathematics: geometry and trigonometry for example are needed to solve more complex problems.

All this to say that there are clear signs that the Standard Model is only the first layer of a more complex theory. Many believe the next layer is a theory called supersymmetry or SUSY.

One major difficulty with this theory is that is has more than 100 free parameters, making it impossible to obtain predictions without assigning fixed values to some of these parameters. This lead to more manageable models, like the Constrained Minimal Supersymmetric Model or CMSSM.

Today, at the International Conference on High Energy Physics, several theorists discussed the impact of the recently revealed mass of the Higgs boson on the CMSSM model. For example, Dmitri Kanikov showed that one can use the intrinsic interconnections within the theory to see how the current limits obtained from the most recent experiments substantially constrain the parameters of the CMSSM.

Nazila Mahmoudi took this approach one step further by imposing constraints not to the CMSSM model but rather to the whole set of free SUSY parameters. This lead her and her colleagues to realize that with the actual searches and mostly, the stringent constraint coming from the Higgs mass at about 126 GeV, many of the constrained models are nearly ruled out.

The vertical axis shows the Higgs boson mass. If one assumes a Higgs mass between 123-129 GeV, scenarios such a minimal Gauge Mediated SUSY Breaking Model and no-scale (shown in gray and magenta) are excluded.

She was very optimistic even though the current searches at the LHC have not yet revealed any new SUSY particles. She showed that in fact there are plenty of values still allowed for the many parameters of SUSY. As she stated, if we have not found SUSY particles yet, it does not mean they are not there but simply that they must be much heavier or belong to more complex configurations, making them harder to find. By eliminating models like that, it helps zoom on the right one.

Nice optimistic way to close this first day of the conference.

Pauline Gagnon

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4 Responses to “New boson could pave the way towards new discoveries”

  1. Rob Halff says:

    What I don’t understand is that scientist can make such an important discovery and just decide to name it H, seems like every discovery which is made is just named something arbitrary.

    Anyway, thanks to the author who I choose to call Ga.p, where p refers to the beginning of her first name and Ga offcourse is a Gagnon.

  2. Rob Halff says:

    Anyway, greetz to Susy…

  3. Discovery of Higgs Boson Particle will open new areas/ fields of research and achievements. This discovery will aide to NANO-TECHNOLOGY, MEDICINE, ASTRONOMY, OUTER SPACE LIFE, SPACE VEHICLE TECHNOLOGY, DEFENSE TECHNOLOGY etc. Such discoveries will change the fate and way of living on Earth.

  4. Sudhir Mittal says:

    Dear Pauline,

    My interezt is limited to the philosophical implications of particle physics. The so called discovery of Higgs Boson disappoints me. Because it lends credence to a theory that requires to predict a particle for every conceivable phenomenenon in the subatomic world. The smugness of the discovery reminds me of Lord Rutherford proclaiming to a class of graduating physicists in 1901/02 that most questions in physics were solved except Black Body radiation (and one more I cant recall). Little did he know the questions were only to usher in a whole new field of new physics. So as a layman I feel particle physics should travel towards convergence and not divergence. It should move in sync with the irrefutable wisdom that the universe is ultimately undifferentiated and undifferentiable. To my mind the Standard Model appears to apply the basic outlook of a machinistic Newtonian world to the quantum world. Though with limited insight into particle physics I have a hunch that this claim of the Standard Model might go the way went the claims to the Steady State Theory. What do you think.

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