# Hunting For The God Particle

Today, Thursday 14th March 2013.  Only last year, the world of Particle Physics research was getting excited among rumours and speculation that the hunt for the Higgs boson at the Large Hadron Collider (LHC) was finally over, following the news that a Higgs-like particle had been identified in July.

Since then, things have changed.  Further analysis has confirmed that the particle is even more Higgs-like, and CERN now officially declares that the discovered particle is indeed ‘a’ Higgs boson”.

But, is it the one and only?  The Higgs boson everyone looked forward to meeting.  The real McCoy, as predicted by the Standard Model.  Or the lightest one of several bosons predicted by theories that go beyond the Standard Model?

Both from King’s College, London, John Ellis and Tevong You think it may well be the former and their Global Analysis of Higgs Couplings to fermions and massive bosons determines that they have the same relative sign as in the Standard Model “beyond any reasonable doubt”.

The value µ measures how closely the decay of the Higgs via several decay channels, or ‘couplings’, resembles that expected of the Higgs boson described by the Standard Model.

The result says it all  $\mu = 1.02_{-0.12} ^{+0.11}$.

A Standard Model Higgs boson ought to have a predicted value of 1, and the measure µ calculated using data from the LHC’s ATLAS and CMS experiments is well within that value.

However, Ellis and You do not give up yet on the possibility of physics beyond the Standard Model, pointing out that the mass and couplings of the Higgs leave the door open to supersymmetry.

The LHC and its experiments are currently shut down for at least two years for a major upgrade designed to enable running experiments at even higher collision energies.  We now look forward to the next LHC run at higher energy, and significantly higher luminosity.

A more definite answer is on hold until 2015…