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Archive for October, 2013

In case you have not found out already, the Nobel prize in physics for 2013 was awarded to Francois Englert and Peter Higgs

“for the theoretical discovery of a mechanism that contributes to our understanding of the origin of mass of subatomic particles, and which recently was confirmed through the discovery of the predicted fundamental particle, by the ATLAS and CMS experiments at CERN’s Large Hadron Collider”

 

Congratulations to the winners of the prize. Here is the link to the official announcement http://www.nobelprize.org/nobel_prizes/physics/laureates/2013/

This is a prize for the so-called Higgs mechanism.  In a certain sense this is another Nobel prize for the Standard model of the electroweak theory of Weinberg and Salam, which was verified experimentally at the LHC with the announcement of a Higgs-like particle on the fourth of July of  2012. The agreement with the Standard model has improved with the additional data that has been taken at the LHC experiment since then.

 

One of my favorite ways of accounting for the Higgs particle is that the electroweak theory of massless gauge Bosons and the Snatdard model Higgs sector has

4\times 2 + 4

bosonic degrees of freedom in the ‘unbroken phase’. This is two polarizations for each massless gauge boson particle, and four degrees of freedom from the Higgs sector of the theory.

This same theory has

3\times 3 + 2+\boxed{\bf 1}

degrees of freedom in the `broken phase’. This is 3 polarizations for  each massive gauge boson, 2 polarizations for the photon and the extra one degree of freedom in the box is the so called Higgs particle.

It is the presence of this extra degree of freedom that was observed at CERN, with all the properties expected from Standard model computations.

 

 

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