What is the HIGGS BOSON and why does physics need it? Stephen Naculich, Department of Physics Uncommon Hour Talk, May 3, 2013
THE HIGGS BOSON 1964: new particle predicted by Peter Higgs
THE HIGGS BOSON 1964: new particle predicted by Peter Higgs July 4, 2012: announcement of Higgs boson discovery at the Large Hadron Collider at CERN
WHY DID IT TAKE SO LONG?
WHY DID IT TAKE SO LONG? mean life: 0.16 zeptoseconds (1 zs = 10 21 s) mass: 133 times the mass of the proton
WHY DID IT TAKE SO LONG? mean life: 0.16 zeptoseconds (1 zs = 10 21 s) mass: 133 times the mass of the proton The Higgs boson is created by the conversion of the kinetic energy of colliding protons into the mass energy of the Higgs (KE mc 2 ) p p v v
WHY DID IT TAKE SO LONG? mean life: 0.16 zeptoseconds (1 zs = 10 21 s) mass: 133 times the mass of the proton The Higgs boson is created by the conversion of the kinetic energy of colliding protons into the mass energy of the Higgs (KE mc 2 ) p p v v At the LHC, the protons have speed v = 0.99999999c
THE TUNNEL
THE BEAMPIPE: containing the beam
SUPERCONDUCTING MAGNETS: bending the beam
1000 TRILLION COLLISIONS
THE DETECTORS: needle in a haystack
THE DETECTORS: needle in a haystack
STANDARD MODEL OF PARTICLE PHYSICS
STANDARD MODEL OF PARTICLE PHYSICS Leptons Quarks Vector bosons
STANDARD MODEL OF PARTICLE PHYSICS Leptons Quarks Three quarks for Muster Mark!" Vector bosons James Joyce, Finnegans Wake
STANDARD MODEL OF PARTICLE PHYSICS Leptons e Quarks u,d Vector bosons
STANDARD MODEL OF PARTICLE PHYSICS Leptons e Quarks u,d Vector bosons p = uud n = udd
STANDARD MODEL OF PARTICLE PHYSICS Leptons e µ Quarks u,d s Vector bosons p = uud n = udd
STANDARD MODEL OF PARTICLE PHYSICS 3 4 5 10 10 10 10 10 MASS (ev) 10 10 10 10 10 6 7 8 9 10 11 12 Leptons e µ Quarks u,d s Vector bosons
STANDARD MODEL OF PARTICLE PHYSICS 3 4 5 10 10 10 10 10 MASS (ev) 10 10 10 10 10 6 7 8 9 10 11 12 Leptons Quarks e u,d cosmic rays µ 1940 s s Vector bosons
STANDARD MODEL OF PARTICLE PHYSICS 3 4 5 10 10 10 10 10 MASS (ev) 10 10 10 10 10 6 7 8 9 10 11 12 Leptons Quarks e u,d cosmic rays accelerators µ τ 1940 s 1970 s s c b Vector bosons
STANDARD MODEL OF PARTICLE PHYSICS 3 4 5 10 10 10 10 10 MASS (ev) 10 10 10 10 10 6 7 8 9 10 11 12 Leptons Quarks Vector bosons e u,d cosmic rays accelerators µ τ 1940 s 1970 s 1995 s c b t 1983 W,Z
STANDARD MODEL OF PARTICLE PHYSICS 3 4 5 10 10 10 10 10 MASS (ev) 10 10 10 10 10 6 7 8 9 10 11 12 ν,ν,ν Leptons Quarks γ, g Vector bosons e u,d cosmic rays accelerators µ τ 1940 s 1970 s 1995 s c b t 1983 W,Z
STANDARD MODEL OF PARTICLE PHYSICS 3 4 5 10 10 10 10 10 MASS (ev) 10 10 10 10 10 6 7 8 9 10 11 12 ν,ν,ν e Leptons cosmic rays accelerators µ τ 1940 s 1970 s 1995 u,d s c b Quarks 1983 γ, g W,Z Vector bosons Why do these particles have such a wide range of masses? t
STANDARD MODEL OF PARTICLE PHYSICS 3 4 5 10 10 10 10 10 MASS (ev) 10 10 10 10 10 6 7 8 9 10 11 12 ν,ν,ν Leptons Quarks e u,d cosmic rays γ, g W,Z Vector bosons Why do these particles have such a wide range of masses? Why do these particles have any mass at all?!! µ s τ 1940 s 1970 s c accelerators b 1983 1995 t
THE HIGGS MECHANISM Standard model has electroweak (EW) symmetry, analogous to the rotational symmetry of a bowl. The center of the bowl is the stable point.
THE HIGGS MECHANISM Standard model has electroweak (EW) symmetry, analogous to the rotational symmetry of a bowl. The center of the bowl is the stable point. EW symmetry = all elementary particles are massless, like the photon.
THE HIGGS MECHANISM Standard model has electroweak (EW) symmetry, analogous to the rotational symmetry of a bowl. The center of the bowl is the stable point. EW symmetry = all elementary particles are massless, like the photon. Like the photon, they should travel at the speed of light. They do not.
THE HIGGS MECHANISM Standard model has electroweak (EW) symmetry, analogous to the rotational symmetry of a bowl. The center of the bowl is the stable point. EW symmetry = all elementary particles are massless, like the photon. Like the photon, they should travel at the speed of light. They do not. Hence, EW symmetry must be broken. How does nature break it?
THE HIGGS MECHANISM Standard model has electroweak (EW) symmetry, analogous to the rotational symmetry of a bowl. The center of the bowl is the stable point. EW symmetry = all elementary particles are massless, like the photon. Like the photon, they should travel at the speed of light. They do not. Hence, EW symmetry must be broken. How does nature break it? One possible solution: the Higgs mechanism. A Higgs field pervades the universe.
THE HIGGS MECHANISM Standard model has electroweak (EW) symmetry, analogous to the rotational symmetry of a bowl. The center of the bowl is the stable point. EW symmetry = all elementary particles are massless, like the photon. Like the photon, they should travel at the speed of light. They do not. Hence, EW symmetry must be broken. How does nature break it? One possible solution: the Higgs mechanism. A Higgs field pervades the universe. Center is no longer stable = particles have mass.
THE HIGGS MECHANISM Standard model has electroweak (EW) symmetry, analogous to the rotational symmetry of a bowl. The center of the bowl is the stable point. EW symmetry = all elementary particles are massless, like the photon. Like the photon, they should travel at the speed of light. They do not. Hence, EW symmetry must be broken. How does nature break it? One possible solution: the Higgs mechanism. A Higgs field pervades the universe. Center is no longer stable = particles have mass. The Higgs field can vibrate.
THE HIGGS MECHANISM Standard model has electroweak (EW) symmetry, analogous to the rotational symmetry of a bowl. The center of the bowl is the stable point. EW symmetry = all elementary particles are massless, like the photon. Like the photon, they should travel at the speed of light. They do not. Hence, EW symmetry must be broken. How does nature break it? One possible solution: the Higgs mechanism. A Higgs field pervades the universe. Center is no longer stable = particles have mass. The Higgs field can vibrate. These quantized vibrations are massive particles called Higgs bosons.
STANDARD MODEL OF PARTICLE PHYSICS 3 4 5 10 10 10 10 10 MASS (ev) 10 10 10 10 10 6 7 8 9 10 11 12 ν,ν,ν Leptons Quarks γ, g Vector bosons Higgs boson e u,d cosmic rays accelerators µ τ 1940 s 1970 s 1995 s c b t? 1983 W,Z
HIGGS DISCOVERY AT LHC
STANDARD MODEL OF PARTICLE PHYSICS 3 4 5 10 10 10 10 10 MASS (ev) 10 10 10 10 10 6 7 8 9 10 11 12 ν,ν,ν Leptons Quarks γ, g Vector bosons Higgs boson e u,d cosmic rays µ s τ 1940 s 1970 s c accelerators b 1983 W,Z 1995 2012? h t