Standard mannequin or not, the Higgs itself revolutionized the sector. “There was a blossoming of new ideas, and the landscape of particle physics completely changed,” says Kado. Carena agrees: “After you discover the Higgs, the first question you have is, ‘Well, why not more of that kind?’” Many theorists have questioned about fashions with a number of Higgs particles, presumably hiding at increased energies, and even whole sectors linked to the Higgs.
Models with Higgs portals—connections to a coterie of extraordinarily feebly interacting particles coupling solely to the Higgs—have flourished due to their means to clarify dark matter and different excellent points with the usual mannequin. Supersymmetric (SUSY) theories—which suggest a brand new symmetry between bosons and fermions—nonetheless have a spot within the theorist’s toolbox, however due to an absence of proof, they’re not predominant. Instead, theorists work extra carefully with experimental outcomes. “There are a lot of inputs we have gotten from experimental data that have constrained the way we build models,” Carena says.
New concepts from theorists have additionally formed the experimental program. This fruitful interaction is probably greatest encapsulated by the effective field theory (EFT) approach on the LHC. Using the EFT strategy, theorists can information experimentalists to make precision measurements delicate to undiscovered particles. For instance, the decay of a Higgs to a Z boson and a photon is mediated by contributions from all particles. If the decay price deviates from predictions, that might be an indication of an unseen heavy particle.
Even if a Higgs decay matches normal mannequin predictions, it might nonetheless present invaluable data. Some different Higgs fashions, Wardle factors out, predict that the Higgs boson {couples} to leptons, such because the electron, in another way than to quarks. As such, figuring out all of the coupling strengths and different Higgs parameters isn’t stamp gathering—as some derisively name such measurements—however an important effort to place limits on theories, he says.
Run 3 will start in earnest on July 5, 2022, the day after the tenth anniversary of the Higgs discovery, promising particle physicists a brand new tranche of knowledge to pore over. Wardle hopes knowledge will enable CMS to succeed in 5 sigma and declare a discovery for the Higgs decay to 2 muons. LHCb (one of many more-specialized LHC experiments) may play a job as properly by probing the Higgs coupling to appeal quarks. The seek for beyond-the-standard-model Higgs properties is “now one of the main pillars of the CMS search program,” says Jan Steggemann, a coleader of Higgs physics for the CMS Collaboration. Carena is especially within the Higgs’ self-coupling, which the High Luminosity LHC—an improve deliberate for 2029—will be capable of measure by way of two-Higgs manufacturing.
