Synopsis: Strongly broken symmetry

New particles decaying to the heaviest elementary particles might reveal the nature of electroweak symmetry breaking.
Synopsis figure
Illustration: Courtesy of CERN

When the Large Hadron Collider turns on, physicists will use the gathered accelerator data to answer detailed questions about the nature of fundamental particles and the forces between them. Topping the list is the nature of the dynamics responsible for the Higgs mechanism that gives the elementary particles their mass. In a paper in Physical Review Letters, Jared Evans and Markus Luty of the University of California Davis, US, show that if the Higgs mechanism is strongly coupled, it might show up at the LHC in the form of new resonances in the production of the heaviest elementary particles.

At high energies, the standard model unifies electromagnetism and the weak nuclear interaction to yield four force‐carrying bosons: the photon, W+, W-, and the Z. This unification occurs because their interactions are invariant under electroweak symmetry. But a new interaction is needed to explain why this symmetry is broken—that is, why the W and Z have mass, while the photon is massless. If the interaction responsible is weakly coupled, it will show up in the form of a Higgs boson. If it is strongly coupled, the new particles will be heavier and finding signals at LHC will be more challenging.

Evans and Luty propose that resonances in final states involving the heaviest elementary particles, such as t¯t and W+W-Z, are a promising signal for strong dynamics in the Higgs sector. These new resonances are predicted to be narrow with masses around 1TeV, and should be produced in reasonable quantities at LHC. This makes them a potentially valuable way to pin down the dynamics underlying the Higgs mechanism. – David Voss


Features

More Features »

Announcements

More Announcements »

Subject Areas

Particles and Fields

Previous Synopsis

Atomic and Molecular Physics

Addressing the crowd

Read More »

Next Synopsis

Particles and Fields

Strangelets in the night

Read More »

Related Articles

Viewpoint: Black Hole Evolution Traced Out with Loop Quantum Gravity
Particles and Fields

Viewpoint: Black Hole Evolution Traced Out with Loop Quantum Gravity

Loop quantum gravity—a theory that extends general relativity by quantizing spacetime—predicts that black holes evolve into white holes. Read More »

Viewpoint: The Plot Thickens for a Fourth Neutrino
Particles and Fields

Viewpoint: The Plot Thickens for a Fourth Neutrino

Confirming previous controversial results, the MiniBooNE experiment detects a signal that is incompatible with neutrino oscillations involving just the three known flavors of neutrinos. Read More »

Viewpoint: Dissecting the Mass of the Proton
Nuclear Physics

Viewpoint: Dissecting the Mass of the Proton

A calculation determines four distinct contributions to the proton mass, more than 90% of which arises entirely from the dynamics of quarks and gluons. Read More »

More Articles