posted on Jul, 7 2012 @ 07:22 PM
Originally posted by Mary Rose
And why would they need a new collider?
If anything, this repeats the pattern whereby a proton/proton (or proton/antiproton) accelerator is used as a discovery machine, while a subsequent
e/e or e+/e- machine is used as a precision measurement tool. Happened before with CERN SPS followed by LEP, now it's LHC followed by ILC
One thing that the proton accelerators are missing is the well defined energy delivered to the collision point. In the proton case, there are 3 quarks
(and many other partons) among which the energy is shared, so only a fraction, which is not too easy to determine, goes into the reaction being
studied. By contrast, e/e machines accelerate point-like object e.g. electrons and/or positrons, and the respective energies can be controlled with a
remarkable precision. This allows for an effective energy scan, which is hard to do with a hadron collider like the LHC. Confer studying a resonance,
you have to have a precise knob to control frequency (in this case, energy) to have the most correct measurement of where things happen.
Why to build a proton accelerator in the first place? Long story short, it's a lot cheaper since there is no (or little) synchrotron radiation emitted
by the beams. Look it up for more info. The next proposed collider is linear and not circular anyhow (while the rest of my exposition above still
works) -- because at this energy scale even a large circular machine will suffer large energy losses via the synchrotron radiation, and a linear
machine, while gigantic, won't have this problem.
edit on 7-7-2012 by buddhasystem because: (no reason given)