Ben Allanach is a professor of theoretical physics at the University of Cambridge. Before that he was a post-doc at LAPP (Annecy, France), CERN (Geneva, Switzerland), Cambridge (UK) and the Rutherford Appleton Laboratory (UK). I noticed a recent article of his in the arxiv, and asked him to report on it here, given the interest that the recent LHC results have stirred in the community. He graciously agreed.... So let us hear it from him! 

Blimey, I'm tired. I'm also elated and excited and grateful to my lovely girlfriend, who's not only putting up with my long hours, distracted head and general ensuing grumpiness, she's even looking after me.

Supernova remnant Cassiopeia A (Cas A) is the remains of a massive star 11,000 light years away that would have appeared to explode about 330 years ago as observed from Earth.

Neutron stars like Cas A contain the densest known matter that is directly observable. One teaspoon of neutron star material weighs six billion tons. The pressure in the star's core is so high that most of the charged particles, electrons and protons, merge resulting in a star composed mostly of uncharged particles called neutrons.