Higgs:The invention and discovery of the 'God Particle'

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Higgs:The invention and discovery of the 'God Particle' Page 23

by Higgs- The Invention


  Einstein’s simple explanation 196 see also general theory of relativity; special theory of relativity

  rho mesons, 192

  Richter, Burton 141, 166

  Nobel prize 141

  Rockefeller Foundation 118

  Royal Institution, London 27

  Rubbia, Carlo 149n, 157–8n, 168, 219

  Nobel prize 152

  and the search for W and Z particles 149–50, 151–2

  and the search for weak neutral currents 131–3, 134

  Rutherford, Ernest 4, 13

  Salam, Abdus 71

  and electro-weak field theory xvi-xviii, xix, xx, 91, 94–5, 153, 158, 181

  Nobel Prize 144

  San Fernando earthquakes 109

  scalar field xvi-ii see also Higgs field(s)

  Schoonschip 105, 105n

  Schrieffer, John 73–4

  Schrödinger, Anny 31

  Schrödinger, Erwin 31–3

  Schwinger, Julian 41, 42

  and quantum electrodynamics 14, 43–4

  weak force carrier speculations 60–1, 153

  Schwitters, Roy 140–1

  science policy shift, UK 169–70

  Second World War 40

  Segrè, Emilio 54–5

  selectrons 182

  Serber, Robert 41, 78–9

  sfermions 182

  Shelter Island conference, 1947 41–2, 43

  Shiga, David 199

  sigma particles 65

  and Eightfold Way 68–9

  sigma-star particles 71

  solid state physics 73, 75, 84, 172, 173

  special theory of relativity 5, 11–2, 38, 43, 88n

  speed of light 12, 28, 85, 88, 209, 212

  squarks 182

  Stabler, Ken ‘Snake’ 161

  Standard Model xi–xii, xiii, 15, 112, 113, 197, 199, 203, 204, 208, 210, 211, 219

  centrality of Higgs field 158–9, 170–1

  concept of mass 221

  flaws 180–1, 182–3

  particles 141–4, 176–7, 180, 192

  Standard Model of big bang cosmology 159, 183

  Standard Solar Model 55n

  Stanford Linear Accelerator Center (SLAC) 112, 120–6, 135

  Stanford Positron Electron Asymmetric Rings (SPEAR) 140–1, 145

  static electricity 27

  stochastic cooling 148, 149–50

  strange quarks 80, 81, 97, 99, 111, 142

  anti-strange quarks 99

  strangeness

  changes in 98, 126

  conservation in strong-force interactions 59

  discovery 58–9, 107

  and Eightfold Way classification 69

  strange-particle decays 59, 101, 126, 185

  values 71, 81, 81n

  Weinberg’s wariness xx, 93

  Strassler, Matt 211

  Strassman, Fritz 40

  Strategic Defense Initiative (‘Star Wars’) 162

  strong nuclear force (colour force) 15, 221

  application of Higgs mechanism 91, 92

  asymptotic freedom 135–7

  carriers see gluons

  convergence with electromagnetic and weak force in MSSM 182–3

  division from electro-weak force 155

  electron-exchange model 46–9

  isospin conservation 45–6, 49

  particles experiencing 64–5

  production of kaons and lambda particles as signal 58

  and quark colours 110–12

  strangeness conservation 59

  SU(2) quantum field theory 50–3, 54, 62, 152–3

  SU(2)×SU(2) quantum field theory 92

  three field particles predicted 50–1, 60 see also quantum chromodynamics

  structure function 122, 123, 124, 125

  superconducting magnets 164, 168, 185–6, 187, 188

  Superconducting Supercollider (SSC, formerly Desertron, Very Big Accelerator) 160–8, 169, 185

  Gammas, Electrons and Muons (GEM) group 164

  Solenoidal Detector Collaborator (SDC) group 164

  superconductors 84

  BCS theory 73–6, 109

  supercooling 156–7

  super-particles 183–5, 186

  superstrings xii

  supersymmetry (SUSY) xii, 181–5

  Susskind, Leonard xvii

  symmetry 23

  symmetry breaking 75–8

  application to electro-nuclear force 155, 157, 158

  application to electro-weak force 92–4, 98, 101, 104–7, 126, 153, 154, 158

  and acquisition of mass in Nambu–Jona-Lasinio model 76–7, 92

  and acquisition of mass via Higgs mechanism 85–9

  and electromagnetism/weak nuclear force distinction 126

  grand unification epoch 155

  and Nambu-Goldstone bosons 77–8, 92

  symmetry groups:

  SU(2) 50

  SU(3) global 68, 70, 71, 72, 80, 97

  SU(3) local 97

  SU(5) 155

  U(1) 33, 45, 75, 94

  symmetry transformations 23–7

  continuous 24–7, 28, 30

  discrete 23–4

  global 29

  local 29–30

  synchrotrons 119–20

  ‘t Hooft, Gerard xx, 103–7, 137n

  tau leptons 142

  Higgs boson decay channels 178

  tau neutrinos 142

  discovery 177, 180

  Taylor, Richard 122

  technicolour force xvii, 171n

  Teller, Edward 41, 46

  Tevatron see Fermi National Accelerator Laboratory

  Thatcher, Margaret 171–3

  Theories of Everything (TOE) xi–xii, 155n

  ‘three-sigma’ evidence 193, 195, 202, 204, 206

  Thompson, Joseph John 4

  Timaeus (Plato) 2

  Ting, Samuel 140, 141

  Nobel Prize 141

  Tomonaga, Sin-Itiro 14, 44, 73

  Tonelli, Guido 188, 210

  top quarks 142, 143, 160

  discovery 176, 180

  Higgs boson decay channels 178

  LHC detection 192

  mass 176–7

  Tye, Henry 156

  up quarks 80, 81, 96–7, 99, 110, 111, 141, 176, 220–1

  mass 139

  upsilons:

  discovery 142

  LHC detection 192

  uranium 9

  uranium atoms 9, 194

  neutron bombardment 40

  uranium-235 12, 119

  US Department of Energy 162, 195

  van de Meer, Simon 147–8

  Nobel Prize 152

  van Hove, Leon 149–50, 150n

  Van Vleck, John 41

  Veltman, Martinus xx, 102–6, 149n

  Very Big Accelerator (VBA) 160 see also Superconducting Supercollider

  von Neumann, John 41

  W particles 142

  acquisition of mass 93, 94, 107, 154, 171, 172

  decays 60, 99–100, 176

  discovery xvii, 151–2, 153

  emissions 81, 99

  exchange 126–7

  Higgs boson decay channels 178, 197, 203

  LEP ‘factory’ 160

  LHC detection 192

  mass 94, 144, 158

  predicted 60, 61, 62, 65, 91, 126

  search for 129, 144–53

  W-boson ‘loops’ 197

  Waldegrave, William 169, 170, 176

  Walker, Alan 206

  Waller, Ivar 107

  Walton, Ernest 118

  Ward, John xvi

  water, molecular weight 10

  wave mechanics 33

  wave/particle duality 5, 32, 35–6

  weak nuclear force 15, 54–6, 64

  carriers see W particles; Z particles

  convergence with electromagnetic and strong force in MSSM 182–3

  conservation of strangeness unrespected 59

  hierarchy problem 180–1

  hierarchy problem resolved 182

&
nbsp; parallels with electromagnetism 55, 60

  post-big bang division from electromagnetic force 154 see also electro-weak quantum field theory

  weak neutral currents 63, 93, 94, 98–101

  experimental establishment 134

  search for 126–34

  weakly interacting massive particles (WIMPS) 183

  Weinberg, Steven xiv-xxi, 61, 91–2, 106–7, 153, 155, 158, 166, 171n, 181, 182

  Dreams of a Final Theory 165

  Nobel Prize 144

  and search for weak neutral currents 127, 128

  SU(2)×U(1) field theory of leptons 92–4, 98, 101, 102

  Weisskopf, Victor 41

  Wess, Julius 181

  Weyl, Hermann 29, 36

  gauge theory 30–1, 33–5

  Wheeler, John 41

  Wigner, Eugene 49

  Wilczek, Frank xx, 136–7, 140

  Williamson, Jody 90–1

  Wilson, Charles 128

  Wilson, Robert 145–6, 149, 150, 150n

  winos 182

  Woit, Peter 196, 213

  world-wide web, invention 170

  Wu, Chieng-Shiung 55

  Wu, Sau Lan 197

  xi particles 65

  and Eightfold Way 68–9

  xi-star particles 71

  Y-12, Tennessee 119

  Yale University 64

  Yang, Chen Ning ‘Frank’ 46, 49–53, 54, 60, 152

  Yang Mills field theories 77, 102–6, 158

  SU(2) 50–3, 54, 62, 152–3

  SU(2) × U(1) 62–3, 67, 91, 92–5, 98–102, 106–7, 126, 153

  SU(2)×SU(2) 92

  SU(3) 111

  SU(3)×SU(2)×S(1) 112, 138, 181 see also electro-weak field theory

  Yukawa, Hideki 51, 73, 137n

  Z particles 142

  acquisition of mass 93, 94, 107, 154, 171, 172

  discovery xvii, 152, 153

  exchange 127

  Higgs boson decay channels 178, 179, 197, 203

  LEP ‘factory’ 160

  LHC detection 192

  mass 65, 94, 144, 158

  predicted 62, 65, 91, 126

  search for 144–54

  and weak neutral currents 63, 93, 98–9, 126

  zinos 182

  Zumino, Bruno 181

  Zurich University 31

  Zweig, George 83, 84

  Zwicky, Fritz 183

  * For brevity, I will refer to this work as ‘the 1964 papers’.

  * See Plato, Timaeus and Critias, Penguin, London (1971), pp. 73–87. Plato built air, fire, and water from one type of triangle and earth, Penguin, London (1971), pp. 73–87. Plato built air, fire, and water from one type of triangle and earth from another. Consequently, Plato argued that it is not possible to transform earth into other elements.

  * There are elements heavier than uranium, but these do not occur in nature. They are inherently unstable and must therefore be produced artificially in a laboratory or a nuclear reactor. Plutonium is perhaps the best-known example.

  * The density of pure ice at 0°C is 0.9167 grams per cubic centimetre. The ice cube has a volume of about 19.7 cubic centimetres, so its mass is a little over 18 grams.

  * Of course, we need to be careful to distinguish between weight and mass. The ice cube weighs 18 grams on earth but it weighs a lot less on the moon and nothing at all in orbit around the earth. Its mass, however, remains firmly fixed. By convention, we set the mass to be equal to its earthly weight.

  * In fact, the equation E = mc2 does not appear in this form in Einstein’s paper.

  * Fortunately for the value of the world’s gold reserves, this does not provide a cheap way to transform base metals into gold.

  * I enjoyed just such a ride whilst working as a postdoctoral researcher in California in the early 1980s. I think it was called the ‘Tidal Wave’.

  * There is evidence to suggest that women’s bodies actually become more symmetrical in the 24 hours prior to ovulation. See Brian Bates and John Cleese, The Human Face, BBC Books, London (2001), p. 149.

  * Time to explain what we mean here by ‘fields’. The field associated with a force such as gravity or electromagnetism has both a magnitude and a direction at every point in the space surrounding the object that generates it. You can detect this field by placing in it another object that is susceptible to the force. Pick up any object (preferably nothing breakable) and drop it. The object’s response is governed by the magnitude and direction of the gravitational field at the precise point where you let go. The object feels the force, and falls to the ground.

  * This is ‘imaginary’ only in the sense that it is not possible to calculate the square root of –1. When squared, any positive or negative number will always give a positive answer. But even though the square root of –1 doesn’t exist, this doesn’t stop mathematicians from using it. Thus, the square root of any negative number can be expressed in terms of i. For example, the square root of –25 is 5i, which is called a complex or imaginary number.

  † These were called ‘light-quanta’ by Einstein in 1905. Today we call them photons.

  ‡ A familiar example of a phase wave is provided by a ‘Mexican’ wave travelling around a sports stadium. The wave is created by the motions of individual spectators as they change positions, from standing with their arms raised (the phase ‘peak’) to sitting in their seats (the phase ‘trough’). The phase wave is the result of the coordinated movements of the spectators, and can travel around the stadium a lot faster than can the individual spectators who support it.

  * The de Broglie relationship is written λ = h/p, where λ is the wavelength (related to the reciprocal of the frequency), h is Planck’s constant, and p is the momentum. This means that p = hc/ν, where c is the speed of light and ν is the frequency.

  * Not sure? Try this. The sum of the infinite series of integer numbers, 1 + 2 + 3 + 4 +…, is obviously infinity. But then, so is the sum of the infinite series of even integer numbers, 2 + 4 + 6 + 8 +…. So, let’s subtract infinity from infinity by subtracting the series of even numbers from the series of integer numbers. What we get is an infinite series of odd numbers, 1 + 3 + 5 + 7 +…, which also sums to infinity but which is nevertheless an entirely ‘sensible’ result. This example is taken from Gribbin, p. 417.

  * These numbers are subject to constant refinement, both experimental and theoretical. The values quoted here are taken from G.D. Coughlan and J.E. Dodd, The Ideas of Particle Physics: An Introduction for Scientists. Cambridge University Press, 1991, p. 34.

  * This was a scholarship administered by America with funds paid by the Chinese as compensation for the Boxer uprising towards the end of the nineteenth century.

  * The masses of sub-atomic particles are typically given as energies, related by Einstein’s equation m = E/c2. The proton mass is 938.3 MeV/c2, where MeV means mega (million) electron volts. The neutron mass is 939.6 MeV/c2. The c2 term is often omitted (which means it is implied) and the masses are then given simply as 938.3 and 939.6 MeV, respectively. An electron volt is the amount of energy a single negatively charged electron gains when accelerated through a one-volt electric field.

  * Those looking for an even more profound consequence of weak-force interactions should look no further than the Standard Solar Model, the contemporary theory describing how the sun works. The fusion of protons (hydrogen nuclei) to form helium nuclei at the sun’s core involves transformation of two protons into two neutrons via the weak force, accompanied by the emission of two positrons and two neutrinos.

  * In fact, their truck couldn’t quite make it all the way to the toll gate and they had to be towed the rest of the way. The scientists’ budget for these experiments was extremely limited but they were fortunate to encounter a vice-president of General Motors, testing a new Chevrolet truck on the mountain. He kindly arranged for the scientists’ truck to be towed and paid for the engine to be replaced.

  * Actually, the ratio of the proton and electron rest masses (the masses that these particl
es would possess at zero speed) is 1836.

  * This was a confusing time. As will become apparent shortly, the mu-meson does not in fact belong to the class of particles that would collectively become known as ‘mesons’.

  * Much the same idea was put forward at around the same time by Japanese physicists Kazuhiko Nishijima and Tadao Nakano, who referred to strangeness as ‘η-charge’.

  * Glashow originally referred to the neutral particle as B, by analogy with Yang and Mills, but it is now commonly referred to as the Z0.

  * These are: right views, right intention, right speech, right action, right living, right effort, right mindfulness, and right concentration.

  * Laser light is an example of this kind of condensation involving photons.

  * The currently accepted value of the charge on the electron is 1.602176487 (40)×10–19 coulomb, where the numbers in brackets represent the uncertainty in the last two decimal places.

  * The relation is a little bit more involved than this. In fact, the isospin is given as half×(number of up-quarks minus number of anti-up-quarks) minus (number of down-quarks minus number of anti-down-quarks).

  † Again, the relation is a bit more involved. Strangeness is given as minus (number of strange-quarks minus number of anti-strange-quarks).

  * These three papers were all published in the same volume (13) of the journal Physical Review Letters in 1964, on pp. 321–3, 508–9, and 585–7, respectively.

  * Unlike other quantum fields we have so far encountered in this book, the Higgs is a ‘scalar’ field – it has magnitude at every point in space-time but no direction. In other words, it does not ‘pull’ or ‘push’ in any particular direction.

  * Note that it is accelerated motion which is impeded. Particles moving at a constant velocity are not affected by the Higgs field. For this reason the Higgs field does not conflict with Einstein’s special theory of relativity.

  * By contributing specifically to a cosmological constant, first introduced as a ‘fudge factor’ by Einstein in his gravitational field equations. In the lambda-CDM model of Big Bang cosmology, the cosmological constant (lambda) controls the rate of expansion of space-time.

  † This is a Dutch naval expression meaning to clean up a messy situation. Veltman later claimed he chose this name to annoy everybody not Dutch.

  * The Nobelprize.org website states flatly that: ‘Professor Gell-Mann has presented his Nobel Lecture [on 11 December 1969], but did not submit a manuscript for inclusion in this volume.’

 

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