Habemus Higgs

Por: System Administrator En: Jue 14 de Mar, 2013 22:38 -05 (5458 Lecturas)

White smoke arose from the Champagne bottles at the CERN headquarters today (and maybe in the Peter Higgs's house also), after the least conservative word combination: "a Higgs", instead of "a new boson" was allowed to be used by the speakers from CMS at Moriond Conference

, in order to present the long-awaited

updated results in the $H\to \gamma\gamma$ channel. Like with the other fumata bianca, it also has

nothing to do

with god

. We will need to wait at least until 2015

to know if the discovered Higgs is in fact "the Higgs" (the standard model one). From the current combined data of ATLAS+CMS, it is expected strong evidence that the dicovered particle has spin-0, positive parity, and couples also to fermions. Any way, all have been settled for this year Nobel prize

, specially after the press release from CERN

At the Moriond Conference today, the ATLAS and CMS collaborations at the Large Hadron Collider (LHC) presented preliminary new results that further elucidate the particle discovered last year. Having analysed two and a half times more data than was available for the discovery announcement in July, they find that the new particle is looking more and more like a Higgs boson, the particle linked to the mechanism that gives mass to elementary particles. It remains an open question, however, whether this is the Higgs boson of the Standard Model of particle physics, or possibly the lightest of several bosons predicted in some theories that go beyond the Standard Model. Finding the answer to this question will take time.

Whether or not it is a Higgs boson is demonstrated by how it interacts with other particles, and its quantum properties. For example, a Higgs boson is postulated to have no spin, and in the Standard Model its parity – a measure of how its mirror image behaves – should be positive. CMS and ATLAS have compared a number of options for the spin-parity of this particle, and these all prefer no spin and positive parity. This, coupled with the measured interactions of the new particle with other particles, strongly indicates that it is a Higgs boson.

“The preliminary results with the full 2012 data set are magnificent and to me it is clear that we are dealing with a Higgs boson though we still have a long way to go to know what kind of Higgs boson it is,” says CMS spokesperson Joe Incandela.

"The beautiful new results represent a huge effort by many dedicated people. They point to the new particle having the spin-parity of a Higgs boson as in the Standard Model. We are now well started on the measurement programme in the Higgs sector," says ATLAS spokesperson Dave Charlton.

To determine if this is the Standard Model Higgs boson, the collaborations have, for example, to measure precisely the rate at which the boson decays into other particles and compare the results to the predictions. The detection of the boson is a very rare event – it takes around 1 trillion (1012) proton-proton collisions for each observed event. To characterize all of the decay modes will require much more data from the LHC.

Image from: www.chemistryviews.org

: Sparkling Wine, Champagne & Co – Part 2, Author: Klaus Roth,2010, DOI: 10.1002/chemv.201000043