Thanks to Resonaances for this plot from Alessandro Strumia's talk. Even for an unconstrained fairy field mass, the LHC will leave only a few percent of the parameter space. Goodbye Susy.
The most ironic thing in this is that they blame the poor people that dare to have another thinking of how things are. Like it would be their fault there is no SUSY. When the mainstream has all the money and all the power to also make plan B:s.
Talk of getting blowed :) What a luck we have viXra :)
Yes, good for vixra and other free document servers. But ... see that black dashed line in the plot? THERE IS STILL ROOM for Susy on that string! How can it not be there, if all the world's 'smartest' men think it must be? Susy must be one hot chick, and that's all any 'real' man wants in a woman, heh?
That plot, out of context, is very misleading. In reality, there is plenty of interesting SUSY parameter space left.
I think SUSY is the nicest idea we have that stabilises the weak scale. Other ideas like technicolour and little Higgs models are too contrived, in my opinion. But having said that, I'm happy to give up the idea of low-scale SUSY if it is not found in the next few years, during which time the LHC really will close down the parameter space.
Of course, it is plausible that our universe is described up to very high energies by a fine-tuned standard model. That means we will only see the Higgs at the LHC, and high-energy particle physics will become very boring.
I agree with you Rhys. Essentially, all that has been done is to put a lower limit on the gluino mass ~700 GeV. However, it is definitely possible for the gluino mass to be as large as 2 TeV. So, the wild-eyed claims by amateur physics enthusiast such as Kea here to the effect that SUSY is ruled out or disfavored are quite premature.
Evil, you may find comfort in thinking so, but I am not an amateur. The problem with the gluino is not that it might have a mass of so many GeV, but that it is a bad idea, and that better ideas exist. Good theorists make concrete predictions for experiments, and I have long predicted that Susy would not be seen. Of course, numerical predictions are more impressive, so you should probably consider those before continuing with this pathetic demonstration of Anonymous Cowardus behaviour.
What is your alternative to the Higgs mechanism? I think I've asked you this before, but can't remember getting an answer. You never seem to discuss dynamics on this blog, but electroweak symmetry breaking (or, more prosaically, the masses of the W and Z) is a dynamical issue.
Would you like to enlighten us as to exactly why a gluino, and by extension supersymmetry, is a bad idea? Does it not provide an elegant way to stabilize the electroweak scale? Does it not results in precision gauge coupling unification and provide a natural dark matter candidate? I feel very confident that your 'prediction' that SUSY will not be seen will turn out to be wrong.
Rhys and Evil, I have been talking about electroweak symmetry breaking on this blog (and elsewhere) for some years now. I can't help it if you don't get it. And the gluino is NOT elegant, because there is NO fixed objective scale to be stabilized. Geometry is emergent in quantum gravity. If you want gauge coupling unification, it comes from the qutrit Jordan algebra over the bioctonions and other fields. That's right; we can DERIVE stringy symmetries in our approach. Kind of makes it obvious that Susy is dead, don't you think?
I rather like the D-brane description of the Higgs mechanism. This description is very much in the spirit of the noncommutative geometry approach to quantum gravity.
In the D-brane description, given N coincident branes, the gauge symmetry is U(N). From the short strings stretched between the branes, there are N scalars coming from the modes with coordinates transverse to the worldvolume. These describe the positions of the N branes in the directions transverse to the worldvolume and the D-brane positions in spacetime are promoted to a matrix in the adjoint rep. of the unbroken U(N). Giving some of the scalars expectations values, geometrically corresponding to moving the branes apart from each other in the transverse space, thus breaking the gauge symmetry from U(N) to a subgroup, acting as a Higgs mechanism. To accomplish this dynamically, one uses the Dirac-Born-Infeld action.
To make contact with noncommutative geometry, one may consider the algebra M(N,C) of NxN matrices over the complex field C. It is a noncommutative C*-algebra and is interpreted as an algebra of functions over N points. Such points correspond to idempotents in the C*-algebra. In the N=2 case, M(2,C) acts on a 2-point fuzzy sphere. Connes has made use of this, and the 2-point space actually corresponds to the complex projective line CP^1 with isometry group U(2). Hermitian elements in M(2,C), have two real eigenvalues, which are its values on the two coordinate patches of CP^1. This is most easily seen by looking at the spectral decomposition of a Hermitian element of M(2,C).
Going back to the D-brane description, one may use the spectral triple (M(2,C),CP^1,D) of the N=2 case to describe a system of two coincident branes. By describing each massless mode using a Chan-Paton Hermitian matrix in M(2,C), the short fundamental strings are packaged into elements of a noncommutative C*-algebra, allowing one to identify the U(2) internal degree of freedom of the fundamental string on the world-volume with the isometry group of CP^1. The fundamental strings are hence noncommutative (complex) functions over the 2-point space. For general N, one can use the spectral triple (M(N,C),CP^{N-1},D) and the results are similar.
To acquire a gauge symmetry different than U(N), one can consider the more general family of algebras M(N,K), where K is a composition algebra. This includes the octonionic case K=O, where for N=2 and N=3 one recovers SO(9) and F4 gauge symmetry, which act as isometry groups for OP^1 and OP^2. For higher N, the construction of OP^N is hindered by topological obstructions, so the octonionic case is quite special.
Emergent geometry, as noncommutive geometry, therefore has the meaning von Neumann envisioned when he coined the term: it is a form of geometry in which algebras of functions are replaced by noncommutative algebras. Coordinates are replaced by generators of such algebras, and since such generators do not commute, they cannot be simultaneously diagonalized and the space, as classically envisioned, disappears.
The most ironic thing in this is that they blame the poor people that dare to have another thinking of how things are. Like it would be their fault there is no SUSY. When the mainstream has all the money and all the power to also make plan B:s.
ReplyDeleteTalk of getting blowed :)
What a luck we have viXra :)
Yes, good for vixra and other free document servers. But ... see that black dashed line in the plot? THERE IS STILL ROOM for Susy on that string! How can it not be there, if all the world's 'smartest' men think it must be? Susy must be one hot chick, and that's all any 'real' man wants in a woman, heh?
ReplyDeleteIf you knew Susy like I knew Susy, Oh wow what a gal! She never strung me along. :-)
ReplyDeleteLol, ThePeSla. Yes, I guess Susy herself was always an honest sort. Just not her fans.
ReplyDeleteThat plot, out of context, is very misleading. In reality, there is plenty of interesting SUSY parameter space left.
ReplyDeleteI think SUSY is the nicest idea we have that stabilises the weak scale. Other ideas like technicolour and little Higgs models are too contrived, in my opinion. But having said that, I'm happy to give up the idea of low-scale SUSY if it is not found in the next few years, during which time the LHC really will close down the parameter space.
Of course, it is plausible that our universe is described up to very high energies by a fine-tuned standard model. That means we will only see the Higgs at the LHC, and high-energy particle physics will become very boring.
Still not paying attention, Rhys? The LHC will see no fairy field.
ReplyDeleteI agree with you Rhys. Essentially, all that has been done is to put a lower limit on the gluino mass ~700 GeV. However, it is definitely possible for the gluino mass to be as large as 2 TeV. So, the wild-eyed claims by amateur physics enthusiast such as Kea here to the effect that SUSY is ruled out or disfavored are quite premature.
ReplyDeleteEvil, you may find comfort in thinking so, but I am not an amateur. The problem with the gluino is not that it might have a mass of so many GeV, but that it is a bad idea, and that better ideas exist. Good theorists make concrete predictions for experiments, and I have long predicted that Susy would not be seen. Of course, numerical predictions are more impressive, so you should probably consider those before continuing with this pathetic demonstration of Anonymous Cowardus behaviour.
ReplyDeleteWhat is your alternative to the Higgs mechanism? I think I've asked you this before, but can't remember getting an answer. You never seem to discuss dynamics on this blog, but electroweak symmetry breaking (or, more prosaically, the masses of the W and Z) is a dynamical issue.
ReplyDeleteWould you like to enlighten us as to exactly why a gluino, and by extension supersymmetry, is a bad idea? Does it not provide an elegant way to stabilize the electroweak scale? Does it not results in precision gauge coupling unification and provide a natural dark matter candidate? I feel very confident that your 'prediction' that SUSY will not be seen will turn out to be wrong.
ReplyDeleteRhys and Evil, I have been talking about electroweak symmetry breaking on this blog (and elsewhere) for some years now. I can't help it if you don't get it. And the gluino is NOT elegant, because there is NO fixed objective scale to be stabilized. Geometry is emergent in quantum gravity. If you want gauge coupling unification, it comes from the qutrit Jordan algebra over the bioctonions and other fields. That's right; we can DERIVE stringy symmetries in our approach. Kind of makes it obvious that Susy is dead, don't you think?
ReplyDeleteFor those who think the standard model is elegant, you might make a blog post about its ugly bunny shaped Lagrangian.
ReplyDeleteWell, if there is no singular Higgs, are there then any Higgs mechanism or mexican hat?
ReplyDeleteThe more force is used the more far away it goes?
But I am no expert.
I rather like the D-brane description of the Higgs mechanism. This description is very much in the spirit of the noncommutative geometry approach to quantum gravity.
ReplyDeleteIn the D-brane description, given N coincident branes, the gauge symmetry is U(N). From the short strings stretched between the branes, there are N scalars coming from the modes with coordinates transverse to the worldvolume. These describe the positions of the N branes in the directions transverse to the worldvolume and the D-brane positions in spacetime are promoted to a matrix in the adjoint rep. of the unbroken U(N). Giving some of the scalars expectations values, geometrically corresponding to moving the branes apart from each other in the transverse space, thus breaking the gauge symmetry from U(N) to a subgroup, acting as a Higgs mechanism. To accomplish this dynamically, one uses the Dirac-Born-Infeld action.
To make contact with noncommutative geometry, one may consider the algebra M(N,C) of NxN matrices over the complex field C. It is a noncommutative C*-algebra and is interpreted as an algebra of functions over N points. Such points correspond to idempotents in the C*-algebra. In the N=2 case, M(2,C) acts on a 2-point fuzzy sphere. Connes has made use of this, and the 2-point space actually corresponds to the complex projective line CP^1 with isometry group U(2). Hermitian elements in M(2,C), have two real eigenvalues, which are its values on the two coordinate patches of CP^1. This is most easily seen by looking at the spectral decomposition of a Hermitian element of M(2,C).
Going back to the D-brane description, one may use the spectral triple (M(2,C),CP^1,D) of the N=2 case to describe a system of two coincident branes. By describing each massless mode using a Chan-Paton Hermitian matrix in M(2,C), the short fundamental strings are packaged into elements of a noncommutative C*-algebra, allowing one to identify the U(2) internal degree of freedom of the fundamental string on the world-volume with the isometry group of CP^1. The fundamental strings are hence noncommutative (complex) functions over the 2-point space. For general N, one can use the spectral triple (M(N,C),CP^{N-1},D) and the results are similar.
To acquire a gauge symmetry different than U(N), one can consider the more general family of algebras M(N,K), where K is a composition algebra. This includes the octonionic case K=O, where for N=2 and N=3 one recovers SO(9) and F4 gauge symmetry, which act as isometry groups for OP^1 and OP^2. For higher N, the construction of OP^N is hindered by topological obstructions, so the octonionic case is quite special.
Emergent geometry, as noncommutive geometry, therefore has the meaning von Neumann envisioned when he coined the term: it is a form of geometry in which algebras of functions are replaced by noncommutative algebras. Coordinates are replaced by generators of such algebras, and since such generators do not commute, they cannot be simultaneously diagonalized and the
space, as classically envisioned, disappears.
What happened to my fairly detailed comment/question?
ReplyDeleteRhys, your question is more than adequately covered by kneemo's response here. This is my blog, and I decide what comments are posted.
ReplyDelete