A refined search for the extremely rare transformation of the Higgs boson has yielded results, providing the first evidence of a process that could imply unknown particles.
The results of several years’ worth of proton crashes inside two different detectors at the European Organization for Nuclear Research’s (CERN) Large Hadron Collider (LHC) have been reconciled, researchers have discussed. physicist the statistical precision of the rate at which the famous ‘mass-giving’ particle decays into a photon and a Z boson.
The results, shared with LHC Physics Conference in Belgrade last week, short of what could have been considered significant. But the process itself can be improved to hone in on the bubble and hiss of quantum recipes, and help identify where strange new forces and building blocks might exist.
The Higgs particle became the darling of the physics world in 2012 when evidence of its existence was confirmed by ATLAS (or ‘A Toroidal LHC Apparatus’) and CMS (Compact Muon Solenoid) detector at CERN.
Not only was this the last entry in that grand map of particles – the Standard Model – to be confirmed experimentally; its observation promises to be a window into hidden parts of the quantum realm.
For the most part, knowing that the Higgs particle and its associated field exist means that we now understand why fundamental particles have mass.
Because energy and mass are different ways of describing the same type of thing, the effort required to combine large and dense objects (such as atoms, molecules, and elephants) contributes a large proportion of the mass of thing.
On a smaller scale, the effort required for more fundamental objects like electrons or quarks to walk through the Higgs field explains why they have a resting mass, and why particles like photons do not.
However, the field’s collectivity and its effervescent froth of bosons make it an ideal candidate to look for signs of a hypothetical quantum field and related particles that don’t usually distinguish themselves in a more obvious way.
“Each particle has a special affinity for the Higgs boson, making the search for the rare Higgs a high priority,” said the physics coordinator for CERN’s ATLAS experiment, Pamela Ferrari.
The decay of a grain is like the death of a pigeon among skyscrapers – it happens all the time, usually in different ways, but you’ll be lucky to catch more than a few drifting feathers as evidence of their passing.
Fortunately, by counting all those ‘feathers’ in a collider’s dust-up, physicists can build a picture of the different ways particles fall and briefly reappear in new things.
Some of these decays are quite common, but for the Higgs particle, the transformations into a photon and the short-range weak nuclear force-carrying Z boson are about one-in-a-thousand events. Or, as predicted in the textbooks, about 0.15 percent of all Higgs decays.
But that’s all the Standard Model dictates we should expect. As wonderfully insightful as that grand theory is, we know it will fail at some point, because it doesn’t have much to say about space-stretching dark energy or the warping of space and time in a gravity-like manner.
Any variation from this figure can be used to support alternative models that may leave just enough room to fit disturbing facts.
Figuring out how to improve the best physics model we have means finding a bunch of anomalies it can’t currently explain. Like strange fields and particles that perform subtle and extraordinary actions that we normally don’t notice.
“The presence of new particles could have a huge impact on the rare Higgs decay modes,” said Florencia Canelli, physics coordinator of CERN’s other detector, the CMS.
For now, the elusive unicorn particles are as contrived as ever. The results so far are roughly within the range of what the Standard Model predicts.
However, there is only enough data to make physicists moderately confident that the results are correct. Larger runs, perhaps using better technology, may even reveal small differences that hide a large window into a whole new set of theories.
“This study is a powerful test of the Standard Model,” said Canelli.
“In the ongoing third run of the LHC and beyond High Luminosity LHCwe will be able to improve the accuracy of this test and detect even rarer Higgs decays.”
