Today marks ten years since the announcement of the Higgs Boson's discovery. The international ATLAS and CMS collaborations at Large Hadron Colliders (LHC), have published the results of their most extensive studies to date of the unique particle's properties. Independent studies published in Nature today show that the particle's properties match those predicted by the Standard Model for particle physics. These studies show that the particle has become a powerful tool to find new phenomena. If found, they could shed light on some of physics' most elusive mysteries, like the nature of dark matter, which is mysteriously present in the universe.

The Higgs boson, which is the particle manifestation, is a part of the all-pervasive quantum field, also known as the Higgs fields. It is fundamental for understanding the universe as it exists. This field would have prevented elementary particles, such as the quarks in the protons and neutrons, as well the electrons surrounding the nuclei from having mass. It would also have prevented the W bosons, which carry the charged weak force that initiates the nuclear reaction that powers our Sun.

ATLAS and CMS combine many complementary processes that produce and "decay" into Higgs bosons to explore the full potential for LHC data.

These are the results of their independent studies using the full LHC Run2 data sets. They each contain over 10 000 trillion proton-proton collisions, and approximately 8 million Higgs Bosons. This is 30 times more than the time the particle was discovered. Each of these new studies combines an unprecedented number of Higgs boson decay and production processes, allowing for the most detailed and precise measurements of their rates and the Higgs boson interactions with other particles.

The measurements all match the Standard Model predictions. However, there are uncertainties due to the process's abundance. An uncertainty of 6% was achieved for the Higgs boson’s interaction strength with carriers of weak force. Comparatively, similar analyses using the complete Run 1 data sets produced a 15% uncertainty in that interaction strength.

Andreas Hoecker, ATLAS spokesperson, said that after ten years of Higgs boson research at the LHC the ATLAS/CMS experiments provided a detailed map showing its interactions with force carriers as well as matter particles. "The Higgs sector has very deep connections with very profound questions about the evolution and stability of the early universe, as well the striking mass pattern for matter particles. The Higgs boson discovery sparked an intense, deep, and broad experimental effort that will continue throughout the entire LHC program."

"Sketching such a portrait the Higgs boson so early on was impossible before the LHC began operating," says Luca Malgeri, spokesperson for CMS. This achievement is due to many factors, including the outstanding performance of the LHC and the ATLAS and CMS detectors as well as the innovative data analysis techniques used.

These new combination analyses provide new results that include stringent limits on the interaction of the Higgs Boson with itself, as well as new, undiscovered phenomena beyond the Standard Model. For example, the Higgs Boson decays into invisible particles which may be dark matter.

ATLAS and CMS will continue to reveal the nature of Higgs bosons using data from Run 3 at the LHC, which begins tomorrow at a new high energy frontier and the major upgrade to the collider, the High-Luminosity LHC, (HL-LHC) starting in 2029. The collaborations are expected to reduce the uncertainty in measuring the Higgs Boson's interactions. They also plan to observe the Higgs boson interactions with lighter matter particles, and the first evidence of its interaction with itself.

The ATLAS Collaboration, A detailed map of Higgs boson interactions by the ATLAS experiment ten years after the discovery, Nature (2022).DOI: 10.1038/s41586-022-04893-w. www.nature.com/articles/s41586-022-04893-w