The Higgs Boson is often referred to as “the God particle” by the media, after the title of Leon Lederman’s book, The God Particle: If the Universe Is the Answer, What Is the Question?. While use of this term may have contributed to increased media interest in particle physics and the Large Hadron Collider, many scientists dislike it, since it overstates the particle’s importance, not least since its discovery would still leave unanswered questions about the unification of QCD, the Electroweak interaction and gravity, and the ultimate origin of the universe. In a renaming competition, a jury of physicists chose the name “the champagne bottle boson” as the best popular name. The Higgs boson is a hypothetical massive elementary particle predicted to exist by the Standard Model of particle physics.
The existence of the particle is postulated as a means of resolving inconsistencies in current theoretical physics, and attempts are being made to confirm the existence of the particle by experimentation, using the Large Hadron Collider (LHC) at CERN and the Tevatron at Fermilab. The Higgs boson is the only Standard Model particle that has not been observed in particle physics experiments. It is a consequence of the so-called Higgs mechanism which is the part of the Standard Model that explains how most of the known elementary particles become massive. For example, the Higgs boson would explain the difference between the mass-less photon, which mediates electromagnetism, and the massive W and Z bosons, which mediate the weak force.
If the Higgs boson exists, it is an integral and pervasive component of the material world. If it exists, it is of a class of particles known as scalar bosons. Bosons have integer spin, and scalar bosons have spin 0. The photon is a kind of boson, and so is the less-familiar gluon, along with the W and Z particles mentioned above. But these particles are all vector bosons, with spin 1. At present there are no known elementary scalar bosons in nature, although many composite spin-0 particles are known.
Theories exist that do not anticipate the Higgs boson, described elsewhere as Higgsless models. Relatively model-independent arguments suggest that any mechanism which generates the masses of the elementary particles must be visible below 1.4 TeV. Therefore the Large Hadron Collider is expected to provide experimental evidence of the existence or non-existence of the Higgs boson. Experiments at Fermilab also continue previous attempts at detection, albeit hindered by the lower energy of the Tevatron accelerator, although it theoretically has the necessary energy to produce the Higgs boson.The Higgs mechanism (or “Englert-Brout-Higgs-Guralnik-Hagen-Kibble” ) is a mechanism by which vector bosons can get a mass. It was proposed in 1964 independently and almost simultaneously by three groups of physicists: François Englert and Robert Brout, by Peter Higgs, (who was inspired by the ideas of Philip Anderson); and by Gerald Guralnik, C. R. Hagen, and Tom Kibble.
The three papers written on this discovery were each recognized as milestone papers during Physical Review Letters’s 50th anniversary celebration. While each of these famous papers took similar approaches, the contributions and differences between the 1964 PRL Symmetry Breaking papers are noteworthy. These six physicists were also awarded the 2010 J. J. Sakurai Prize for Theoretical Particle Physics for this work. Steven Weinberg and Abdus Salam were the first to apply the Higgs mechanism to the electroweak symmetry breaking. The Higgs mechanism not only explains how the electroweak vector bosons get a mass, but predicts the ratio of the W boson and Z boson masses as well as their couplings among themselves and with the Standard Model quarks and leptons.
Many of these predictions have been verified by precise measurements performed at the LEP and the SLC colliders, thus confirming that the Higgs mechanism takes place in nature. Out of the three seminal papers on the Higgs mechanism, only the paper by Peter Higgs mentioned, in a closing sentence, possible existence of the Higgs boson (“… an essential feature of the type of theory which has been described in this note is the prediction of incomplete multiplets of scalar and vector bosons.”). Peter Higgs added this sentence when he was revising the paper after it was rejected by Physics Letters, and before resubmitting it to Physical Review Letters. The first detailed description of the Higgs boson properties was given in 1966, also by Peter Higgs. The Higgs boson existence is not a strictly necessary consequence of the Higgs mechanism: the Higgs boson exists in some but not all theories which use the Higgs mechanism. For example, Higgs boson exists in the Standard Model and the Minimal Supersymmetric Standard Model. Yet it is not expected to exist in Technicolor models or, more generally, Higgsless models. All of these models realize various forms of the Higgs mechanism. A major goal of the LHC experiments is to distinguish among these models and determine if the Higgs boson exists or not.