We still need to talk about the Higgs boson

Almost six years after the Higgs boson has been dis­cov­ered, it still hasn’t lost its magic. It remains in the spot­light of physics con­fer­ences and is still a favorite topic in the media.

Since the the­o­ret­i­cal pre­dic­tion of the exis­tence of the Higgs boson by physi­cists Peter Higgs, Franҫois Englert, Robert Brout, and oth­ers in the 1960s, the enor­mous efforts to exper­i­men­tally ver­ify this ele­men­tary par­ti­cle was some­thing like the search for the holy grail of par­ti­cle physics.

The dis­cov­ery of the Higgs boson at the Large Hadron Col­lider is often con­sid­ered as the end of a long effort to com­plete the stan­dard model of par­ti­cle physics. Though, at the same time, the fur­ther study and explo­ration of the Higgs boson offers new pos­si­bil­i­ties to study the uni­verse at the small­est scales, and even to study new physics and devi­a­tions from the stan­dard model.

With the dis­cov­ery of the Higgs boson, a long and very suc­cess­ful chap­ter of par­ti­cle physics has been closed, while at the same time, the first lines of a new chap­ter have been writ­ten.

Or as Tim Ger­shon, pro­fes­sor at the Uni­ver­sity of War­wick, UK, and a mem­ber of CERN's LHCb col­lab­o­ra­tion, put it in a recent arti­cle in the CERN courier:
"We need to talk about the Higgs. The dis­cov­ery of the Higgs boson marks the begin­ning, not the end, of a fas­ci­nat­ing jour­ney."

The dis­cov­ery of the Higgs boson marks the begin­ning, not the end, of a fas­ci­nat­ing jour­ney.Tim Ger­shon

"The Higgs boson is a totally new type of fun­da­men­tal par­ti­cle that allows unprece­dented tests of elec­troweak sym­me­try break­ing. It thus pro­vides us with a novel micro­scope with which to probe the uni­verse at the small­est scales."

Ger­shon com­pares the Higgs boson research with the after­math of the ground­break­ing detec­tion from 2017, when, for the first time ever, astronomers had observed both grav­i­ta­tional waves and light (elec­tro­mag­netic radi­a­tion) from the same event, the merger of two neu­tron stars. This was achieved with the help of many earth and space-​based obser­va­to­ries and tele­scopes and marked the start of the so-​called "multi-​messenger" astron­omy.

Call­ing it “multi-​messenger par­ti­cle physics”, Ger­shon sees the Higgs as a vehi­cle or micro­scope, together with, for exam­ple, the beauty quark, which already pro­vides hints of new phe­nom­ena, to study new physics at the small­est scales and devi­a­tions from the stan­dard model.

How the results of our research are com­mu­ni­cated to the pub­lic has never been more impor­tant.Tim Ger­shon

So far it seems clear that the dis­cov­ered Higgs boson looks like the par­ti­cle pre­dicted by the stan­dard model, but this can still be ques­tioned.

In an exclu­sive inter­view, Nigel Lock­yer, head of the par­ti­cle physics lab Fer­mi­lab in the US said study­ing the Higgs could has­ten major dis­cov­er­ies.

The Higgs, hav­ing a spin of zero, is the only fun­da­men­tal "scalar" par­ti­cle.
"The Higgs is the first fun­da­men­tal scalar that has ever been observed. And pretty much all physics beyond the stan­dard model con­tains scalars. So these scalars would mix with the Higgs - the ques­tion is how strongly. But what you're look­ing for is evi­dence of the Higgs mix­ing with other scalars. That would be a win­dow into new physics," said Lock­yer.

The LHC didn’t find any signs of new physics yet, but will still run for about two more decades under­go­ing a major upgrade in the 2020s. Physi­cists like Lock­yer hope that study­ing the Higgs boson in more detail, and addi­tion­ally with other col­lid­ers, might bring new insights. A pos­si­ble “Higgs fac­tory” addi­tion­ally to the LHC could be a new electron-​positron col­lider in China, a lin­ear col­lider in Japan, and a post- LHC project at CERN, after the Large Hadron Col­lider comes to the end of its oper­at­ing life­time.

The global Future Cir­cu­lar Col­lider (FCC) study focuses on the design of a 100-​TeV hadron col­lider in a new ∼100 km tun­nel at CERN. The Future Cir­cu­lar Col­lider could offer the com­plete explo­ration of the Higgs boson and a sig­nif­i­cant exten­sion, via direct and indi­rect probes, of the search for physics phe­nom­ena beyond the stan­dard model.

For a deeper under­stand­ing of the Higgs boson and what it's all about, the under­ly­ing con­cepts and ideas lead­ing to its dis­cov­ery and beyond, read our eBook: "The Mys­tery of the Higgs Boson"