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