Higgs search at LHC til December only?

[stglyde]

Do you believe in the news that by December if no Higgs were found. It is like there are really no Higgs because the search windows have been narrowed down already to no more gap by December 31?

If there were no Higgs. What other tests or results can the LHC design to see that can explain electroweak symmetry breaking and masses of particles?

 

[Bill_K]

This year's proton collisions, which includes a search for the Higgs among its goals, ended November 1. All this month the LHC is busy colliding Pb ions. From December thru March 2012 it will be shut down. Proton collisions will resume next year from April thru October. Then in 2013 thru mid 2014 the LHC will be down for a machine upgrade.

Results from this year's run are expected to be announced in March, but they will not be sufficient to draw a definite conclusion. There are many variations on the Higgs theme, and testing them will require at least through the end of 2012, possibly much longer.

 

[stglyde]

If the Higgs were not found. The following list from wikipedia http://en.wikipedia.org/wiki/Higgsless_model are alternatives to it. Which one of the following can be detected by the LHC, or do we need more powerful particle accelerators operational maybe in 2025 to detect the other candidates the break electroweak symmetry? (btw... search for what gives quarks, electron, etc masses are the same for search of what breaks electroweak symmetry?)

1. Technicolor models break electroweak symmetry through new gauge interactions, which were originally modeled on quantum chromodynamics.[1][2]

2. Extra-dimensional Higgsless models use the fifth component of the gauge fields to play the role of the Higgs fields. It is possible to produce electroweak symmetry breaking by imposing certain boundary conditions on the extra dimensional fields, increasing the unitarity breakdown scale up to the energy scale of the extra dimension.[3][4] Through the AdS/QCD correspondence this model can be related to technicolor models and to "UnHiggs" models in which the Higgs field is of unparticle nature.[5]

3. Models of composite W and Z vector bosons.[6]

4. Top quark condensate.

5. "Unitary Weyl gauge". If one adds a suitable gravitational term to the standard model action with gravitational coupling, the theory becomes locally scale invariant (i.e. Weyl invariant) in the unitary gauge for the local SU(2). Weyl transformations act multiplicatively on the Higgs field, so one can fix the Weyl gauge by requiring the Higgs scalar to be a constant.[7][8]

6. Asymptotically safe weak interactions [9] [10] based on some nonlinear sigma models.[11]

7. "Regular Charge Monopole Theory" by Eliyahu Comay.

8. Preon and models inspired by preons such as Ribbon model of Standard Model particles by Sundance Bilson-Thompson, based in braid theory and compatible with loop quantum gravity and similar theories.[12] This model not only explains mass but leads to an interpretation of electric charge as a topological quantity (twists carried on the individual ribbons) and colour charge as modes of twisting.

9. Symmetry breaking driven by non-equilibrium dynamics of quantum fields above the electroweak scale [13] [14].

10. Unparticle physics and the unhiggs [15] [16]. These are models that posit that the Higgs sector and higgs boson are scaling invariant, also known as unparticle physics.

11. In theory of superfluid vacuum masses of elementary particles can arise as a result of interaction with the physical vacuum, similarly to the gap generation mechanism in superconductors.[17][18]

 

[Bill_K]

stglyde, It's way too early to think the Higgs does not exist. In the first place, the results are still consistent with a Standard Model Higgs in the 115-130 GeV range which was the most likely from the beginning. Secondly, the current search assumes Higgs and Higgs only. The addition of just one unknown particle can throw things off.

Quoting Matt Strassler, "If you add a new heavy particle that feels the strong nuclear force and interacts in some way with the Higgs, you will change the rate at which the Higgs particle is produced. Or if you add a new lightweight invisible particle, so that the Higgs particle can decay to a pair of them, then some fraction of the time the Higgs particle, even when produced, can decay invisibly, making it harder to find. The number of variations on these themes is very, very large. Thus, even a Standard Model Higgs sector can be much harder or much easier to detect in a world with other extra particles. And it is often very much harder to search for and exclude these variants."