A new measurement of the mass of the Higgs boson with a precision of 0.09 percent has been revealed by the ATLAS Collaboration at CERN. This kind of accuracy can help us better understand many other particle interactions since the Higgs mass is one of the fundamental factors that defines many elements of the cosmos.
The Higgs boson, the final particle to be discovered in the Standard Model, was considered the great white whale of particle physics for many years. It was the main purpose of the Large Hadron Collider’s construction. The physics community was satisfied in 2012 when it was discovered with enough certainty, which resulted in the 2013 Nobel Prize. Even then, there was still a great deal of mystery about the Higgs mass—possibly the most significant discovery we could make about it outside its existence.
Several attempts have been made since then to further reduce the range of feasible masses, and this most recent result is the most successful to date.
Subatomic particle masses are expressed in electron volts, which may seem perplexing until you realize that, aside from the squared speed of light multiplier, energy and mass are equivalent according to Einstein’s well-known equation. The new measurement indicates that the mass of the Higgs is 125.11 ± 0.11 gigaelectron volts (GeV).
This places the Higgs mass close to the bottom of the 125–126 GeV range reported in the 2012 announcement. The genuine value turns out to be pretty close to the middle of the mass range required for the Higgs to be the particle we believed it was, according to previous studies. This means that the particle’s mass needed to be between 114 and 143 GeV.
Colleagues including Peter Higgs, for whom the particle is named, came to the conclusion that the Higgs was required since a particle carrying the Higgs Field had to exist. Many particles would gain mass as a result, especially the W and Z particles that carry the weak nuclear force. Simply said, the universe could not function without these particles.
That was in 1964, and it took over 50 years to find it. After that, it took another ten years and counting to further refine the mass. The precise mass value determines how the Higgs interacts with other particles, defining both the early universe and the many other physics-related aspects that we expect and search for today.
Finding and measuring the mass of such an important particle may appear straightforward, but one important aspect of the Higgs is its short lifetime. It should last between 10 and 22 seconds. As a result, we can only reconstruct the Higgs from the products it decays into; we are never able to see the Higgs itself.
In this instance, the measurement was made by first creating Higgs bosons by violently smashing protons together, and then monitoring their disintegration. Two pathways were used for the decay: either to high-energy gamma rays or to a real and virtual Z boson pair, which decayed to four observed leptons in total.
