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Dear Lubos,

Does string theory offer a concrete prediction for the mass of the higgs boson?

Thanks

Dan

PS would you mind if I cross-post your response at sci.physics or PF?

dan | 10.01.06 - 5:58 pm | #

Dear dan,

string theorists - just like everyone else - are unable to give a unique prediction for the Higgs mass at this moment although more particular models are more concrete.

The lower bound is 114 GeV because they have not yet been seen, an upper bound may be derived from the need to restore the unitarity of the elastic scattering of pairs of W bosons, and is below 800 GeV or so.

Supersymmetric theories (or supersymmetric vacua in string theory) predict the lightest Higgs to be much lighter than 800 GeV, typically below 200 GeV. A lot of extra information can be derived from the renormalization group running - a dependence of similar parameters on the characteristic energy scale of the experiment.

For example, there exists another lower theoretical bound from the condition that the Higgs doesn't become a tachyone at higher energy scales. That would destabilize the vacuum which would be a worse catastrophe than global warming.

Please feel free to share anything I write here.

Have a nice evening

Lubos

Lubos Motl | Homepage | 10.01.06 - 9:36 pm | #

Hi Dan,

On Sunday 01 Oct 2006 23:00, you wrote:

> I've been looking at your articles, including

> http://arxiv.org/abs/physics/0301034, I'm wondering if

> you have a prediction for the Higgs Boson mass-energy,

> which may be seen at LHC.

>

Yes, indeed, from my model you can predict

the higgs mass. But this prediction is rather

embarrassing: NONE, because the particle masses

in this model are energies of the moving and

oscillating particle constituents (preons).

From this point of view the preon could be

regarded as the higgs since it is the preon

that gives particles their masses.

On the other hand, when you look at the complete

set of structures that emerge under the supposed

symmetry of the basic field, you will find that

this set could be one-to-one mapped to the variety

of known particles. There are some extra particles

that appear in my model, but they are neutral closed

shells, which could only be identified with WIMPs.

So, there are no candidates for the higgs particle

in my model, unless you take seriously the idea

of identifying the higgs and preons (indeed,

the preon is the only unidentified particle in my

model and, like higgs, it corresponds to a scalar field

permeating the whole universe). However, it follows

from my model that preons cannon be found in free

states, unless when the energy becomes comparable

to that of the initial state of the universe. Therefore,

my model predicts that higgs will likely not to be

seen at LHC.

Ragards,

Vladimir

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