Higgs boson

The Higgs boson (or BEH boson or ABEGHHK'tH boson) is an extremely unstable elementary particle with spin zero, no electric charge, and no color charge. The existence of the Higgs boson proves the existence of the Higgs field, which is a quantum field that exists throughout spacetime and breaks certain symmetry laws of the electroweak interaction. The Higgs boson is (as of 2020) the latest addition to the Standard Model of particle physics. Its experimental confirmation in 2012 won the 2013 physics Nobel prize for Peter Higgs and François Englert.

Quotes

 * At the heart of the Higgs physics programme is the question of how the Higgs boson couples to Standard Model elementary particles. Within the SM itself, all these couplings are uniquely determined. But new physics beyond the SM (BSM) can modify these couplings in many different ways.
 * J. de Blas, et al.:


 * The discovery ... of the Higgs boson will mark a watershed in particle physics. In the future, the calendar of particle physics will surely be divided into BH (before Higgs) and AH (after Higgs), with 2012 being year 0. The discovery of the Higgs will signpost the direction that both theoretical and experimental physics will take in the decades to come.
 * ,, and , (quote from p. 13)


 * ... the famous particle bears the name of Peter Higgs alone. Over the years, all the prestigious prizes in physics have been awarded to different combinations of Brout, Englert, Higgs, Guralnik, Hagen and Kibble. ... Nambu's insight to apply the concept of spontaneous symmetry breaking to empty space was profound. In the strange quantum world, what we think of as empty space is anything but. Instead, it is a seething soup of particles constantly popping in and out of existence, and it is this structure in the vacuum itself that gives rise to particle masses. The thing that fills the vacuum is what has come to be known as the Higgs field. Some particles interact strongly with this field, others not at all, and it is the strength of the interaction with the HIggs field that determines the fundamental particles' masses.


 * In regards to the mechanism, Brout and Englert make some comments, but give no quantitative argument. In the Higgs PRL paper, there is only the specific scalar electrodynamics example. In his physics letters paper Higgs observed that an argument given by Gilbert to negate the Goldstone theorem includes a term with a fixed vector such as can be found in radiation gauge electrodynamics. He makes no follow-up or extension of this argument in his PRL paper. The GHK paper does an extensive analysis of the mechanism and shows that in broken gauge theories in the radiation gauge that charge leaks out of any volume and consequently is not conserved since currents continue to exist in the limit of volumes tending toward infinity. This negates the basic assumption of a conserved charge that is required by the Goldstone theorem.
 * Gerald S. Guralnik: (quote from pp. 8–9)


 * ... string theory seems to require our world to have a property called supersymmetry. And a supersymmetric Standard Model with string theory boundary conditions has Higgs bosons and explains their properties. ... Finding a Higgs boson thus strongly supports the supersymmetric Standard Model, which in turn supports the notion that string theory is indeed the right approach to nature.
 * Gordon Kane:


 * ... inclusion of the Higgs boson into the unified electroweak theory guaranteed that one could perform finite calculations of physical quantities in the standard model.
 * John Moffat:


 * The key fact about the Higgs boson is that it is the origin of the masses of all known massive elementary particles, including the quarks, leptons, and W and Z bosons. That raises the following question: Why is a new particle needed to give other particles mass? An audience of physicists can understand the answer: Detailed experiments on the weak interactions establish that the Hamiltonian governing elementary particles has exact symmetries that forbid quark, lepton, and boson mass terms. Thus those symmetries must be spontaneously broken. That, in turn, requires a new field to provide the order parameter for the symmetry breaking. Those familiar with contemporary physics will recognize each step in the above argument. But for nonscientists, every step brings in new, technical, and difficult concepts. It is an unsolved problem to present this argument in popular language.
 * Michael Peskin,


 * Higgs, 84, shares the 8m Swedish kronor (£775,000) prize – and no shortage of kudos – with François Englert at the Free University of Brussels for showing how fundamental particles get their masses. Before the theory, the answer to this basic question was unknown. The Royal Swedish Academy awarded the prize for "the theoretical discovery of a mechanism that contributes to our understanding of the origin of mass of subatomic particles, and which recently was confirmed through the discovery of the predicted fundamental particle, by the Atlas and CMS experiments at Cern's Large Hadron Collider."
 * Ian Sample:


 * ... one of the consequences of the electroweak symmetry is that, if nothing new is added to the theory, all elementary particles, including electrons and quarks, would be massless, which of course they are not. So, something has to be added to the electroweak theory, some new kind of matter or field, not yet observed in nature or in our laboratories. The search for the Higgs particle has been a search for the answer to the question: What is this new stuff we need?
 * Steven Weinberg:


 * There is a puzzle about the Higgs particle — which is what makes it relatively light compared to the natural mass scale of elementary particles.
 * Edward Witten:


 * Armed with the most advanced mathematics and a good dose of imagination, a generation of theoretical physicists conceived the idea that the universe must have undergone a transformation, after a tenth of a billionth of a second from the Big Bang. At that instant, the entire structure of space-time crystallized into a new form, following a phase transition, just as water turns into ice below zero degrees. [...] The same physicists also realized that this idea so suggestive as to sound like science fiction implied the existence of a new particle, a granule of the substance that permeates all of space-time. Data presented yesterday at Cern show that that particle-the Higgs boson - really exists, corroborating the fantastic story of the cosmic phase transition.
 * Gian Francesco Giudice. As quoted in 'Vista solo la punta di un fenomeno complesso'' (July 5, 2012)


 * The discovery of the Higgs boson was a fantastic achievement, but not enough to answer all the questions in particle physics. It was a bit like walking into a three-star restaurant and being served soup. We theoretical physicists confidently await a more tantalizing second course.
 * Gian Francesco Giudice. As quoted in Elena Dusi, Sette missioni per sette misteri (January 20, 2013)