Higgs boson

The six authors of the 1964 PRL papers, who received the 2010 J. J. Sakurai Prize for their work; from left to right: Kibble, Guralnik, Hagen, Englert, Brout; right: Higgs.Yang and Mills work on non-abelian gauge theory had one huge problem: in perturbation theory it has massless particles which don’t correspond to anything we see. One way of getting rid of this problem is now fairly well understood, the phenomenon of confinement realized in QCD, where the strong interactions get rid of the massless “gluon” states at long distances. By the very early sixties, people had begun to understand another source of massless particles: spontaneous symmetry breaking of a continuous symmetry. What Philip Anderson realized and worked out in the summer of 1962 was that, when you have both gauge symmetry and spontaneous symmetry breaking, the Nambu–Goldstone massless mode can combine with the massless gauge field modes to produce a physical massive vector field. This is what happens in superconductivity, a subject about which Anderson was (and is) one of the leading experts. Left: Diphoton channel: Boson subsequently decays into 2 gamma ray photons by virtual interaction with a W boson loop or top quark loop.Particularly significant, we should observe decays into pairs of photons (γ γ), W and Z bosons (WW and ZZ), bottom quarks (bb), and tau leptons (τ τ), among the possible outcomes.Today ... we have the standard model, which reduces all of reality to a dozen or so particles and four forces. ... It's a hard-won simplicity remarkably accurate. But it is also incomplete and, in fact, internally inconsistent... This boson is so central to the state of physics today, so crucial to our final understanding of the structure of matter, yet so elusive, that I have given it a nickname: the God Particle. Why God Particle? Two reasons. One, the publisher wouldn't let us call it the Goddamn Particle, though that might be a more appropriate title, given its villainous nature and the expense it is causing. And two, there is a connection, of sorts, to another book, a much older one...Some particles interact with the Higgs field while others don’t. Those particles that feel the Higgs field act as if they have mass. Something similar happens in an electric field – charged objects are pulled around and neutral objects can sail through unaffected. So you can think of the Higgs search as an attempt to make waves in the Higgs field to prove it’s really there.The Higgs boson is essentially a ripple in a field said to have emerged at the birth of the universe and to span the cosmos to this day ... The particle is crucial however: It is the smoking gun, the evidence required to show the theory is right. ϕ = 1 2 ( ϕ 1 + i ϕ 2 ϕ 0 + i ϕ 3 ) , {displaystyle phi ={frac {1}{sqrt {2}}}left({egin{array}{c}phi ^{1}+iphi ^{2}\phi ^{0}+iphi ^{3}end{array}} ight);,}     (1)Note: This article uses the scaling convention where the electric charge, Q, the weak isospin, T3, and the weak hypercharge, YW, are related by Q = T3 + YW. A different convention used in most other Wikipedia articles is Q = T3 + ½ YW. L H = | ( ∂ μ − i g W μ a τ a − i 1 2 g ′ B μ ) ϕ | 2 + μ 2 ϕ † ϕ − λ ( ϕ † ϕ ) 2 , {displaystyle {mathcal {L}}_{H}=left|left(partial _{mu }-igW_{mu }^{a} au ^{a}-i{frac {1}{2}}g'B_{mu } ight)phi ight|^{2}+mu ^{2}phi ^{dagger }phi -lambda (phi ^{dagger }phi )^{2},}     (2) m W = 1 2 v | g | , {displaystyle m_{W}={ frac {1}{2}}vleft|g ight|,}     (3) m Z = 1 2 v g 2 + g ′ 2 , {displaystyle m_{Z}={ frac {1}{2}}v{sqrt {g^{2}+{g'}^{2}}},}     (4) m H = 2 μ 2 ≡ 2 λ v 2 . {displaystyle m_{H}={sqrt {2mu ^{2}}}equiv {sqrt {2lambda v^{2}}}.}     (5) L Y = − λ u i j ϕ 0 − i ϕ 3 2 u ¯ L i u R j + λ u i j ϕ 1 − i ϕ 2 2 d ¯ L i u R j − λ d i j ϕ 0 + i ϕ 3 2 d ¯ L i d R j − λ d i j ϕ 1 + i ϕ 2 2 u ¯ L i d R j − λ e i j ϕ 0 + i ϕ 3 2 e ¯ L i e R j − λ e i j ϕ 1 + i ϕ 2 2 ν ¯ L i e R j + h.c. , {displaystyle {egin{aligned}{mathcal {L}}_{Y}=&-lambda _{u}^{ij}{frac {phi ^{0}-iphi ^{3}}{sqrt {2}}}{overline {u}}_{L}^{i}u_{R}^{j}+lambda _{u}^{ij}{frac {phi ^{1}-iphi ^{2}}{sqrt {2}}}{overline {d}}_{L}^{i}u_{R}^{j}\&-lambda _{d}^{ij}{frac {phi ^{0}+iphi ^{3}}{sqrt {2}}}{overline {d}}_{L}^{i}d_{R}^{j}-lambda _{d}^{ij}{frac {phi ^{1}+iphi ^{2}}{sqrt {2}}}{overline {u}}_{L}^{i}d_{R}^{j}\&-lambda _{e}^{ij}{frac {phi ^{0}+iphi ^{3}}{sqrt {2}}}{overline {e}}_{L}^{i}e_{R}^{j}-lambda _{e}^{ij}{frac {phi ^{1}+iphi ^{2}}{sqrt {2}}}{overline { u }}_{L}^{i}e_{R}^{j}+{ extrm {h.c.}},end{aligned}}}     (6) L m = − m u i u ¯ L i u R i − m d i d ¯ L i d R i − m e i e ¯ L i e R i + h.c. , {displaystyle {mathcal {L}}_{m}=-m_{u}^{i}{overline {u}}_{L}^{i}u_{R}^{i}-m_{d}^{i}{overline {d}}_{L}^{i}d_{R}^{i}-m_{e}^{i}{overline {e}}_{L}^{i}e_{R}^{i}+{ extrm {h.c.}},}     (7)