From Symmetry- “A bouquet of options: Higgs factory ideas bloom”

November 20, 2012
Signe Brewster

Now that a Higgs-like boson has been discovered at the Large Hadron Collider, proposals to build colliders that churn out the new particle are gathering momentum.

higgs
One possible signature of a Higgs boson from a simulated collision between two protons. It decays almost immediately into two jets of hadrons and two electrons, visible as lines.

“If you hurl two oranges together at close to the speed of light, there’s going to be a lot of pulp. But, somewhere in the gooey mess will be the rare splinters left over from two seeds colliding.The Large Hadron Collider at CERN works in a similar way. Protons, each made of quarks and gluons, collide and produce other particles. Roughly once every 5 billion proton collisions, everything aligns and a Higgs-like boson pops out.

Now that a boson with Higgs-like qualities has been found, physicists are calling for something more precise: a Higgs factory that would collide elementary particles to produce Higgs bosons in droves without all the distracting pulp. By colliding particles that don’t break down into composite parts as they produce Higgs-like particles, a Higgs factory could allow a more precise view of the new boson.

Now that the Higgs-like particle is known to have a mass of about 125 billion electronvolts, scientists know that it is within reach of a variety of proposed colliders, both small and large. As a result, proposals for Higgs factories have emerged for colliders that smash electrons with positrons, muons with muons, or photons with photons.

Linear electron–positron colliders are among the largest and most expensive Higgs factories because they are designed to be versatile. Two proposed machines, known as the International Linear Collider and the Compact Linear Collider, would be 3.4 miles and 1.35 miles long respectively. It would cost at least $5 billion to build the ILC or CLIC…

lic
A view of the two beam lines in the CLIC experimental hall.

Electron–positron colliders can also be circular. The LHC tunnel was originally built for the Large Electron–Positron collider, which produced the first precise measurements of the W and Z bosons in the 1980s. One proposal, called LEP3, would build a Higgs factory in the LHC tunnel, most likely after the LHC shuts down. It would cut costs by using existing infrastructure, such as some of the particle detectors and the cryogenics system.”

lep
LEP, preceded the LHC at CERN

See the full article here. There is much more important material here.

Symmetry is a joint Fermilab/SLAC publication.