The colour force between quarks is carried by eight different kinds of force particle collectively called gluons. This force increases in strength not as the quarks come closer together, as might be expected, but as they separate. The strong nuclear force between protons and neutrons is merely a remnant, a ‘hang-over’ of the colour force between their constituent quarks.
The discovery of a new particle at CERN suggests strongly that the quark masses are derived from interactions with the Higgs field. These interactions transform otherwise massless quarks into particles with mass. The interactions give the particles depth, causing them to slow down. This resistance to acceleration is what we call mass.
But the masses of the quarks are quite small, accounting for just one per cent of the mass of a proton or neutron. The other 99 per cent is derived from the energy carried by the massless gluons which flit between the quarks and bind them together.
In the Standard Model the concept of mass, as an intrinsic property or measure of an amount of substance, has gone. Mass is instead constructed entirely from the energy of the interactions that occur between elementary quantum fields and their particles.
The Higgs boson is part of the mechanism that explains how all the mass of all the particles in the universe is constructed. All the matter in the world might consist of quarks and leptons, but it owes its very substance to the energy gained through interactions with the Higgs field and the exchange of gluons.
Without these interactions, matter would be as ephemeral and insubstantial as light itself, and nothing would be.
ENDNOTES
Prologue: Form and Substance
1 Albert Einstein, Annalen der Physik. 18 (1905), p. 639. English translation quoted in John Stachel (ed.), Einstein’s Miraculous Year: Five Papers that Changed the Face of Physics, Princeton University Press (2005), p. 161.
Chapter 1: The Poetry of Logical Ideas
1 Auguste Dick, Emmy Noether 1882–1935, Birkhäuser, Boston (1981), p. 32. English translation by H.I. Blocher.
2 Albert Einstein, letter to Hermann Weyl, 8 April 1918, quoted in Pais, Subtle is the Lord, p. 341.
3 Louis de Broglie, ‘Recherches sur la Théorie des Quanta’, PhD Thesis, Faculty of Science, Paris University (1924), p. 10. English translation by A.F. Kracklauer.
4 Albert Einstein, New York Times, 5 May 1935.
Chapter 2: Not a Sufficient Excuse
1 Julian Schwinger, interview with Robert Crease and Charles Mann, 4 March 1983. Quoted in Crease and Mann, p. 127.
2 Richard Feynman, interview with Robert Crease and Charles Mann, 22 February 1985. Quoted in Crease and Mann, p. 139.
3 Freeman Dyson, letter to his parents, 18 September 1948. Quoted in Schweber, p. 505.
4 Feynman, p. 7.
5 Chen Ning Yang, Selected Papers with Commentary, W.H. Freeman, New York (1983). Quoted by Christine Sutton in Farmelo (ed.), It Must be Beautiful, p. 241.
6 Robert Mills, telephone interview with Robert Crease and Charles Mann, 7 April 1983. Quoted in Crease and Mann, p. 193.
7 Part of a conversation reported by Yang at the International Symposium on the History of Particle Physics, Batavia, Illinois, 2 May 1985. Quoted in Riordan, p. 198.
8 Quoted in Enz, p. 481.
9 Chen Ning Yang, Selected Papers with Commentary, W.H. Freeman, New York (1983). Quoted by Christine Sutton in Farmelo (ed.), It Must be Beautiful, p. 243.
10 C.N. Yang and R.L. Mills, Physical Review, 96, 1 (1954), p. 195.
Chapter 3: People Will Be Very Stupid About It
1 Emilio Segrè, Enrico Fermi: Physicist, University of Chicago Press (1970), p. 72.
2 Isidor Rabi, quoted in Helge Kragh, Quantum Generations, p. 204.
3 Willis Lamb, Nobel Lectures, Physics 1942–1962, Elsevier, Amsterdam (1964), p. 286.
4 Quoted by Helge Kragh as ‘physics folklore’ in Quantum Generations, p. 321.
5 Murray Gell-Mann and Edward Rosenbaum, Scientific American, July 1957, pp. 72–88. The idea of ‘strangeness’ was also elaborated around the same time by Japanese physicists Kazuhiko Nishijima and Tadao Nakano (who called it η-charge). Although the term strangeness was retained, the theory is sometimes referred to as Gell-Mann–Nishijima theory.
6 Sheldon Glashow, Harvard University PhD thesis (1958), p. 75. Quoted in Glashow, Nobel Lectures, Physics 1971–1980, Edited by Stig Lundqvist, World Scientific, Singapore (1992), p. 496.
7 Murray Gell-Mann, interview with Robert Crease and Charles Mann, 3 March 1983. Quoted in Crease and Mann, p. 225.
8 Murray Gell-Mann, Caltech Report CALT-68-1214, pp. 22–23. Quoted in Crease and Mann, pp. 264–265.
Chapter 4: Applying the Right Ideas to the Wrong Problem
1 Nambu, p. 180.
2 Robert Serber, telephone interview with Robert Crease and Charles Mann, 4 June 1983. Quoted in Crease and Mann, p. 281.
3 Murray Gell-Mann, interview with Robert Crease and Charles Mann, 3 March 1983. Quoted in Crease and Mann, p. 281.
4 Murray Gell-Mann, interview with Robert Crease and Charles Mann, 3 March 1983. Quoted in Crease and Mann, p. 282.
5 George Zweig, ‘An SU(3) Model for Strong Interaction Symmetry and its Breaking’, CERN Preprint 8419/TH.412, 21 February 1964, p. 42.
6 P.W. Anderson, Physical Review, 130 (1963), p. 441, reproduced in E. Farhi and R. Jackiw (eds.), Dynamical Gauge Symmetry Breaking: A Collection of Reprints, World Scientific, Singapore (1982), p. 50.
7 Peter Higgs, in Hoddeson, et al., p. 508.
8 Peter Higgs, Physical Review Letters, 13, 509 (1964).
9 Sidney Coleman, quoted by Peter Higgs in ‘My Life as a Boson: the Story of the “Higgs”’, presented at the Inaugural Conference of the Michigan Center for Theoretical Physics, 21–25 May 2001.
10 Peter Higgs, in Hoddeson, et al., p. 510.
11 Steven Weinberg, Nobel Lectures, Physics 1971–1980, edited by Stig Lundqvist, World Scientific, Singapore (1992), p. 548.
12 Steven Weinberg, interview with Robert Crease and Charles Mann, 7 May 1985. Quoted in Crease and Mann, p. 245.
Chapter 5: I Can Do That
1 Steven Weinberg, quoted by John Iliopoulos in an interview with Michael Riordan, 4 June 1985. Quoted in Riordan, p. 211.
2 Sheldon Glashow, Nobel Lectures, Physics 1971–1980, edited by Stig Lundqvist, World Scientific, Singapore (1992), p. 500.
3 Gerard ’t Hooft, In Search of the Ultimate Building Blocks, Cambridge University Press (1997), p. 58.
4 Martinus Veltman, private communication to Andrew Pickering, quoted in Pickering, p. 178.
5 Gerard ’t Hooft, interview with Robert Crease and Charles Mann, 26 September 1984. Quoted in Crease and Mann, pp. 325–6.
6 Martinus Veltman in Hoddeson, et al., p. 173.
7 Sheldon Glashow, quoted by David Politzer, interview with Robert Crease and Charles Mann, 21 February 1985. Quoted in Crease and Mann, p. 326.
8 Gerard ’t Hooft, in Hoddeson, et al., p. 192.
9 Murray Gell-Mann, in Hoddeson, et al., p. 629.
10 W.A. Bardeen, H. Fritzsch, and M. Gell-Mann, Proceedings of the Topical Meeting on Conformal Invariance in Hadron Physics, Frascati, May 1972. Quoted in Crease and Mann, p. 328.
11 Murray Gell-Mann in Hoddeson, et al., p. 631.
Chapter 6: Alternating Neutral Currents
1 Richard Feynman, interview with Michael Riordan, 14–15 March 1984. Quoted in Riordan, p. 152.
2 Richard Feynman, interview with Paul Tsai, 3 April 1984. Quoted in Riordan, p. 150.
3 Richard Feynman, quoted by Jerome Friedman in an interview with Michael Riordan, 24 October 1985. Quoted in Riordan, p. 151.
4 Donald Perkins in Hoddesson et al., p. 430.
5 Carlo Rubbia, letter to Andre Lagarrigue, 17 July 1973. Quoted in Crease and Mann, p. 352.
6 Donald Perkins, CERN Courier, 1 June 2003.
7 David Cline, quoted in Crease and Mann, p. 357.
Chapter 7: They Must Be Ws
1 W.A. Bard
een, H. Fritzsch, and M. Gell-Mann, Proceedings of the Topical Meeting on Conformal Invariance in Hadron Physics, Frascati, May 1972. Quoted in Crease and Mann, p. 328.
2 Frank Wilczek, MIT Physics Annual 2003, p. 35.
3 Pierre Darriulat, in Cashmore et al., p. 57.
4 Simon van der Meer, quoted in Brian Southworth and Gordon Fraser, CERN Courier, November 1983.
5 Pierre Darriulat, in Cashmore et al., p. 57.
6 Carlo Rubbia, quoted in Brian Southworth and Gordon Fraser, CERN Courier, November 1983.
7 Lederman, p. 357.
Chapter 8: Throw Deep
1 Howard Georgi and Sheldon Glashow, Physical Review Letters, 32 (1974), p. 438.
2 Howard Georgi, interview with Robert Crease and Charles Mann, 29 January 1985. Quoted in Crease and Mann, p. 400.
3 Guth, p. 176.
4 New York Times, 6 June 1983.
5 The full quotation reads: I would rather be ashes than dust; I would rather my spark should burn out in a brilliant blaze; Than it should be stifled in dry rot; I would rather be a superb meteor; With every atom of me in magnificent glow; Than a sleepy and permanent planet. Jack London, quoted in Halpern, p. 151.
6 Attributed to (or associated with) Ken Stabler. The quote was used by journalist George Will in the title of an article about Reagan’s support for the SSC which subsequently appeared in the Washington Post.
7 This short speech from the 1940 film Knute Rockne: All American can be found on the American Rhetoric website at: www.americanrhetoric.com/MovieSpeeches/moviespeechknuterockneallamerican.html
8 Weinberg, p. 220.
9 Lederman, p. 406.
10 Raphael Kasper, quoted in Dallas Morning News, 23 July 2005.
11 Herman Wouk, A Hole in Texas, Little, Brown & Company, New York (2004), Author’s Note.
12 Carlo Rubbia, quoted in Lederman, p. 381.
Chapter 9: A Fantastic Moment
1 William Waldegrave, quoted in Sample, p. 163.
2 David Miller’s submission is available at: http://www.hep.ucl.ac.uk/~djm/higgsa.html. Quoted with permission.
3 David Miller, personal communication, 4 October 2010.
4 Luciano Maiani, CERN Courier, 26 February 2001.
5 http://cms.web.cern.ch/cms/Detector/FullDetector/index.html
6 Lyndon Evans, quoted in CERN Bulletin 37–38, 2008.
Chapter 10: The Shakespeare Question
1 Fermilab Today Twitter feed, quoted by Tom Chivers, The Telegraph, 13 July 2010.
2 Tommaso Dorigo, ‘Rumours About a Light Higgs’, A Quantum Diaries Survivor, blog entry 8 July 2010, www.science20.com/quantum_diaries_survivor/
3 Leon Lederman, quoted by Tom Chivers, The Telegraph, 13 July 2010.
4 Rolf Heuer, quoted in CERN Bulletin, Monday 31 January 2011.
5 Albert Einstein, quoted in Alice Calaprice (ed.), The Ultimate Quotable Einstein, Princeton University Press, 2011, p. 409.
6 Jon Butterworth, television interview with Krishnan Guru-Murthy, Channel 4 News, 24 April 2011.
7 Jon Butterworth, ‘Rumours of the Higgs at ATLAS’, Life and Physics, hosted by the Guardian, blog entry 24 April 2011. www.guardian.co.uk/science/life-and-physics
8 David Shiga, ‘Elusive Higgs Slips from Sight Again’, New Scientist, 4 May 2011.
9 Jon Butterworth, ‘Told You So… Higgs Fails to Materialise’, Life and Physics, hosted by the Guardian, blog entry 11 May 2011. www.guardian.co.uk/science/life-and-physics
10 Laurette Ponce, interview with the author, 21 June 2011.
11 Rolf Heuer, DG’s Talk to Staff, CERN, 4 July 2011.
12 Lyndon Evans, interview with the author, 22 June 2011.
13 Rolf Heuer, DG’s Talk to Staff, CERN, 4 July 2011.
14 Peter Higgs, interview with the author, 18 August 2011.
15 CERN Press Release, 22 August 2011.
16 Fabiola Gianotti, quoted in CERN Press Release, 13 December 2011.
17 Rolf Heuer, closing remarks, CERN Public Seminar, 13 December 2011.
18 Jon Butterworth, television interview with Jon Snow, Channel 4 News, 13 December 2011.
19 Peter Higgs, quoted by Alan Walker, communication to the author, 13 December 2011.
20 Tommaso Dorigo, ‘Firm Evidence of a Higgs Boson at Last!’, A Quantum Diaries Survivor, blog entry 13 December 2011, www.science20.com/quantum_diaries_survivor/
21 Matt Strassler, ‘Higgs Update Today: Inconclusive, as Expected’, Of Particular Significance, comment on blog entry 13 December 2011, profmattstrassler.com/2011/12/13/
22 Jon Butterworth, communication to the author, 23 December 2011.
23 Joe Incandela, ‘Latest update in the search for the Higgs boson’, CERN Seminar, 4 July 2012.
24 Rolf Heuer, ‘Latest update in the search for the Higgs boson’, CERN Seminar, 4 July 2012.
25 CERN Press Release, 4 July 2012.
26 Peter Higgs, ‘Latest update in the search for the Higgs boson’, CERN Seminar, 4 July 2012.
GLOSSARY
Anti-particle. Identical in mass to an ‘ordinary’ particle but of opposite charge. For example, the anti-particle of the electron (e–) is the positron (e+). The anti-particle of a red quark is an anti-red anti-quark. Every particle in the Standard Model has an anti-particle. Particles with zero charge are their own anti-particles.
Asymptotic freedom. A property of the strong colour force between quarks. The colour force actually declines in strength as quarks are brought closer together, such that in the asymptotic limit of zero separation the quarks behave as though they are completely free – see Figure 17(b), p. 136.
ATLAS. Acronym for A Toroidal LHC Apparatus, one of the two detector collaborations involved in the hunt for the Higgs boson at CERN’s Large Hadron Collider.
Atom. From the Greek atomos, meaning indivisible. Originally intended to denote the ultimate constituents of matter, the word atom now signifies the fundamental constituents of individual chemical elements. Thus, water consists of molecules of H2O, which is composed of two atoms of hydrogen and one atom of oxygen. The atoms in turn consist of protons and neutrons, which are bound together to form a central nucleus, and electrons whose wavefunctions form characteristic patterns called orbitals around the nucleus.
Baryon. From the Greek barys, meaning heavy. Baryons form a sub-class of hadrons. They are heavier particles which experience the strong nuclear force and include the proton and neutron. They are composed of triplets of quarks.
Beta-particle. A high-speed electron emitted from the nucleus of an atom undergoing beta-radioactive decay. See beta-radioactivity/decay.
Beta-radioactivity/decay. First discovered by French physicist Henri Becquerel in 1896 and so named by Ernest Rutherford in 1899. An example of a weak-force decay, it involves transformation of a down-quark in a neutron into an up-quark, turning the neutron into a proton with the emission of a W− particle. The W− decays into a high-speed electron (the ‘beta-particle’) and an electron anti-neutrino.
Big bang. Term used to describe the cosmic ‘explosion’ of space-time and matter during the early moments in the creation of the universe, about 13.7 billion years ago. Originally coined by maverick physicist Fred Hoyle as a derogatory term, overwhelming evidence for a big bang ‘origin’ of the universe has since been obtained through the detection and mapping of the cosmic microwave background radiation, the cold remnant of hot radiation thought to have disengaged from matter about 380,000 years after the big bang.
Billion. One thousand million, 109, or 1,000,000,000.
Boson. Named for Indian physicist Satyendra Nath Bose. Bosons are characterized by integral spin quantum numbers (1, 2,…, etc.) and, as such, are not subject to Pauli’s exclusion principle. Bosons are involved in the transmission of forces between matter particles, and include the photon (electromagnetism), the W and Z particles (weak force), and gluons (colour force). Particles with spin zero are also called bosons but these are not involved in transmitting forces. Examples include the pion
s, Cooper pairs (which can also have spin 1), and the Higgs boson. The graviton, the hypothetical particle of the gravitational field, is believed to be a boson with spin 2.
Bottom quark. Also sometimes referred to as the ‘beauty’ quark. A third-generation quark with charge , spin ½ (fermion), and a ‘bare mass’ of 4.19 GeV. It was discovered at Fermilab in 1977, through the observation of the upsilon, a meson formed from bottom and anti-bottom quarks.
CERN. Acronym for Conseil Européen pour la Recherche Nucléaire (the European Council for Nuclear Research), founded in 1954. This was renamed the Organisation Européenne pour la Recherche Nucléaire (European Organization for Nuclear Research) when the provisional Council was dissolved, but the acronym CERN was retained. CERN is located in the north-west suburbs of Geneva near the Swiss–French border.
Charm-quark. A second-generation quark with charge , spin ½ (fermion), and a ‘bare mass’ of 1.27 GeV. It was discovered simultaneously at Brookhaven National Laboratory and SLAC in the ‘November revolution’ of 1974 through the observation of the J/ψ, a meson formed from a charm- and an anti-charm-quark.
CMS. Acronym for Compact Muon Solenoid, one of the two detector collaborations involved in the hunt for the Higgs boson at CERN’s Large Hadron Collider.
Cold dark matter (CDM). A key component of the current lambda-CDM model of big bang cosmology, thought to account for about 22 per cent of the mass-energy of the universe. The constitution of cold dark matter is unknown, but is thought to consist largely of ‘non-baryonic’ matter, i.e. matter that does not involve protons or neutrons, most likely particles not currently known to the Standard Model. Candidates include weakly interacting massive particles, or WIMPs. They have many of the properties of neutrinos, but are required to be far more massive and therefore move much more slowly. Supersymmetric extensions of the Standard Model suggest that such particles might be neutralinos.
Higgs:The invention and discovery of the 'God Particle' Page 18
