First Definitive Higgs Result In 7 Years

PhysicsDavid writes "In a suite of new results about the Higgs boson, Fermilab presents the first new definitive evidence on the (lack of) existence of the Higgs boson since the Large Electron Positron collider shut down in 2000. Fermilab hasn't found the Higgs, but can rule out a certain range of masses for the particle that is believed to create mass for all the other particles of nature. Other Higgs news suggests a new likeliest mass range of 115 to 135 GeV for the Higgs. These results were among those presented at the ICHEP 2008 conference currently wrapping up in Philadelphia."

Re:Higgs

[Anonymous Coward]

Isn't string theory dying? 25 years or so of intense research by the best brains in the field of physics, yet nothing remotely scientific has come out of it. It appears to be more of a religion than science. Nothing testable, no predictions, setting the background to coax out the result. Plus the "them and us" attitude the believers have these days all string theorist exhibit.

135 GeV seems very high...

[Dice]

Okay, I only have a 4 year degree in Physics so maybe someone can help me out on this. If this particle gives the property of mass then shouldn't it have a mass less than that of the lightest particles? According to a quick Google calculation [google.com] this thing out-masses an electron by 5 orders of magnitude.

WTF?

Re:Higgs

[mcelrath]

Wrong, the higgs mass is absolutely not a prediction of string theory. Any higgs mass can be accommodated in principle. Every measurement rules out branches of string theory. But a heavy higgs would rule out a wide class of favorite string models.

Re:Higgs

[Sockatume]

If there exists a higgs mass which would falsify a "wide class" of string theories, then that is a testable prediction of those theories. ("Higgs mass must be less than X"). Therefore, it is no longer valid to state that string theories as a class are untestable.

Re:Higgs

[Joe Snipe]

I can use deductive reasoning to find my way out of a forest, and it would indeed be the search for truth (the same as the search for scientific truth), but I will still be "emotionally biased" in that I will want the end of the forest to be right over the hill. I have no reason to stop if my hopes are incorrect. I am not sure why you posted this, syousef I think I am missing your point.

Mass actually measured in eV/c^2

[Roger W Moore]

Actually is it not. Mass is correctly expressed in units of GeV/c^2. Einstein showed that energy and mass are equivalent with his famous E=mc^2 relationship. Hence mass, m=E/c^2. Thus we can use units of energy/c^2 to measure mass. This is particularly useful in fields like particle physics because we often convert mass into energy, or vice versa, and so it is useful to know how much energy it takes to create a particle (or is released in a particle decay).

Using units of 'GeV' for mass is actually very sloppy and technically wrong because energy and mass do not have the same dimensions and so cannot have the same physical units. The usual excuse is the use of natural units where c=1. However that '1' has dimensions associated with it and so to ensure that those dimensions are preserved you need to include it in the units. Hence mass is actually measured in 'GeV/c2' and not 'GeV'. Similarly momentum can me measured in units of 'GeV/c'.

Re:Higgs

[Anonymous Coward]

You're wrong. String theory as a class is "untestable" because, regardless of experimental outcome, subsets of string theory are constructable/exist; in other words, no matter what experiments show, the class "string theory" will not be wrong.

Poor string theorists will always construct voidable models which can be disproven--the good theorists however will always have an infinitude of models which can not.

Re:Higgs

[RedOctober]

I remember reading somewhere that some astronomy students, out of perversity, decided to continue working on the Ptolomaic system, adding additional epicycles on top of the ones that were conventional at the time to improve on accuracy, and to add the new planets discovered since then. The end result was a complex system that fairly accurately predicted planetary positions. Of course, it was all done tongue in cheek, but it does demonstrate that certain systems can be tailored ad infinitum to greater levels of accuracy - even if they are wrong in principle.

I wish I could find a link to to this.

Re:Higgs

[Urkki]

If something, like sufficiently complex Ptolomaic explanation of solar system, matches reality to observational limit, then couldn't it be reduced to the more simple theory we know about (Newtonian or GR) with enough and suitable coordinate transforms, simplification of formulas etc?

If so, then it could be argued that the complex Ptolemaic explanation is equally valid because it is actually equal, just expressed in a needlesly complex way...

Higgs field is like ...

[pbhj]

There's a great analogy for this which will probably help, http://www.hep.ucl.ac.uk/~djm/higgsa.html [ucl.ac.uk] .

IIRC this was the result of a competition by Physics World (the magazine of the Inst. of Phys.).