At the recent CERN Moriond Conference, the ATLAS and CMS collaborations at the Large Hadron Collider (LHC) presented preliminary new results, finding 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.
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,” 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.
Physicists hope that a "new physics" will provide a more straightforward explanation for the characteristics of the Higgs boson than that derived from the current Standard Model. This new physics is sorely needed to find solutions to a series of yet unresolved problems, as presently only the visible universe is explained, which constitutes just four percent of total matter.Last summer, scientists hailed the announcement of the Higgs discovery, speculating that it could one day make light speed travel possible by "un-massing" objects or allow huge items to be launched into space by "switching off" the Higgs.* CERN scientist Albert de Roeck likened it to the discovery of electricity, when he said humanity could never have imagined its future applications.
"What's really important for the Higgs is that it explains how the world could be the way that it is in the first millionth of a second in the Big Bang," de Roeck told AFP.* "Can we apply it to something? At this moment my imagination is too small to do that."
Physicist Ray Volkas said "almost everybody" was hoping that, rather than fitting the so-called Standard Model of physics -- a theory explaining how particles fit together in the Universe -- the Higgs boson would prove to be "something a bit different".
"If that was the case that would point to all sorts of new physics, physics that might have something to do with dark matter," he said, referring to the hypothetical invisible matter thought to make up much of the universe.
"It could be, for example, that the Higgs particle acts as a bridge between ordinary matter, which makes up atoms, and dark matter, which we know is a very important component of the universe."
"That would have really fantastic implications for understanding all of the matter in the universe, not just ordinary atoms," he added.* De Roeck said scrutinising the new particle and determining whether it supported something other than the Standard Model would be the next step for CERN scientists.
Definitive proof that it fitted the Standard Model could take until 2015 when the LHC had more power and could harvest more data.
The LHC was due to go offline for a two-year refit in December, 2012 that will see its firepower doubled to 14 trillion electronvolts -- a huge step forward in the search for new particles and clues about what holds them all together. De Roeck said he would find it a "little boring at the end if it turns out that this is just the Standard Model Higgs".
Instead, he was hoping it would be a "gateway or a portal to new physics, to new theories which are actually running nature" such as supersymmetry, which hypothesises that there are five different Higgs particles governing mass.
The existence of the Higgs boson was predicted in 1964 and it is named after the British physicist Peter Higgs. It is the last piece of the puzzle that has been missing from the Standard Model of physics and its function is to give other elementary particles their mass. According to the theory, the so-called Higgs field extends throughout the entire universe. The mass of individual elementary particles is determined by the extent to which they interact with the Higgs bosons.
On the one hand, the Higgs particle is the last component missing from the Standard Model of particle physics. On the other hand, physicists are struggling to understand the detected mass of the Higgs boson. "Using our theory as it currently stands, the mass of the Higgs boson can only be explained as the result of a random fine-tuning of the physical constants of the universe at a level of accuracy of one in one quadrillion," explained Matthias Neubert, of the Institute of Physics at Johannes Gutenberg University Mainz (JGU).