What do you think about CERN?

Question

I mean specifically the hadron collider proj.

Answer 1

They are probably the world's leading organization for nuclear research, way out in front of anything the 'superpowers' ever had.  They've done serious research and won a few Nobel prizes.  

But the biggest thing to come out of CERN has nothing to do with nuclear research.   They invented the World Wide Web.  The WWW could be one of the top ten world-changing inventions of all time!  The US invented the Internet but that was only infrastructure.  Without the WWW it would have been entirely unusable by 90% of the people in the developed countries.  It's the Web that made the Internet useful.

Answer 2

The LHC is intended to look for the Higg's boson and physics beyond the standard model of particle physics such as super symmetry and dark matter/energy candidates. The standard model does not predict that the LHC will produce mini-Black Holes; however, if physics beyond the standard model is found to hold, then mini-Black Holes might be possible. These mini-Black holes might be produced at a rate in the order of one per second. According to the some calculations, these ‘holes’ are harmless because they will quickly decay via ‘Hawking radiation’ and explode into a shower of particles. The problem with ‘Hawking radiation’ is that it too is unproven physics and, thus, might not be a correct explanation for the disappearance of mini-Black Holes. An unlikely, accumulation of mini-Black Holes could be a ‘small’ problem.

Below I will detail some of the physics that the LHC is attempting to explore.

The weak interaction is mediated by spin-1 bosons which act as force carriers between quarks and/or leptons. There are three of these intermediate vector bosons, which were all discovered at CERN in 1983. They are the charged bosons W+ and W- and the neutral Z0. Their masses are measured to be: -

M(W) = 80.3 Gev/c² and M(Z) = 91.2 Gev/c²

which gives their ranges as: -

R(W) ≈ R(Z) ≈ 2 x 10^-3 fm

Their decay modes are as follows: -

W+ -> l+ + vl

W- -> l- + vl'

Z0 -> l+ + l-

Where the l's stand for leptons and the v's for neutrinos with the prime ' indicating an anti-neutrino.

This introduction sets the scene for what follows!

The intermediate vector bosons gain their mass from the Higgs boson. Please allow me to explain.

During the nineteen-sixties the theoretical physicists Glashow, Salam and Weinberg developed a theory which unified the electromagnetic and the weak nuclear forces. This theory is known as the ‘electroweak’ theory, it predicted the neutral vector boson Z0, and weak nuclear force reactions arising from its exchange, in what are known as neutral current reactions. The theory also accounted for the heavy charged bosons W+ and W-, required for the mediation of all observed weak interactions, known as charged current reactions. These particles were discovered in 1983.This unified theory is a ‘gauge invariance’ theory, which means that if the components of its underlying equations are transformed, in position or potential, they still predict exactly the same physics. Because the force carrying particles (Z0, W+ and W-), of this theory, are massive spin-1 bosons a spin-0 boson is required to complete the theory. This spin-0 boson is the as yet unobserved ‘Higgs’ boson.

The masses of the force carrying bosons (Z0, W+ and W-), for the electroweak theory, are derived from their interaction with the scalar Higgs field. Unlike other physical fields, the Higgs field has a non-zero value in the vacuum state, labelled φ0, and furthermore this value is not invariant under gauge transformation. Hence, this gauge invariance is referred to as a ‘hidden’ or ‘spontaneously broken’ symmetry. The Higgs field has three main consequences’. The first, is that the electroweak force carrying bosons (Z0, W+ and W-) can acquire mass in the ratio: -

M(W) =cosθ(W)

_____

M(Z)

Where θ(W) Is the electroweak mixing angle. These masses arise from the interactions of the gauge fields with the non-zero vacuum expectation value of the Higgs field. Secondly, there are electrically neutral quanta H0, called Higgs bosons, associated with the Higgs field, just as photons are associated with the electromagnetic field. Thirdly, the Higgs field throws light on the origin of the quark and lepton masses. In the absence of the Higgs field the requirements of gauge invariance on the masses of spin-½ fermions (quarks and leptons etc,) would set them at zero for parity violating interactions (non-mirror image interactions). Parity is a conserved quantity in strong nuclear force and electromagnetic interactions but is violated in weak nuclear force interactions, which would make quark and lepton masses zero in this later case. However, interactions with the Higgs field can generate fermion masses due to the non-zero expectation value φ0 of this field, as well as with interactions with the Higgs bosons. These interactions have a dimensionless coupling constant g(Hff) related to the fermions mass m(f) by the expression: -

g(Hff) = √ (√2G(f)m(f) ²)

Where G(f) is the Fermi coupling constant and f is any quark or lepton flavour. However, this theory, that the fermion masses are mediated by their interaction with the Higgs field, does not predict their mass m(f). However, with the future discovery of the Higgs boson the above equation can be used to confirm the observed coupling constant g(Hff).

At CERN, the Large Hadron Collider (LHC) will search for the Higgs boson at an energy of up to 1 TeV by colliding protons in the reaction: -

p + p -> H0 + X

Where X is any state allowed by the usual conservation laws.

The upper atmosphere is a more energetic 'particle physics laboratory' than the LHC. If cosmic rays, slamming into the upper atmosphere, create mini-black holes then these decay rapidly! However, it may be that mini-black holes are not produce - at all - in high-energy particle collisions.