Fermilab is still hunting the Higgs boson.FermilabPosted on 03/13/2009 10:04:07 PM PDT by neverdem
Longer search promised after physicists exclude heavy masses for the 'God particle'.
The Higgs boson particle may be lighter — and the race to find it tougher — than particle physicists had hoped, according to the latest results from the Tevatron particle accelerator at the Fermi National Accelerator Laboratory in Batavia, Illinois.
Fermilab is still hunting the Higgs boson.FermilabOn 13 March, scientists there announced that they had ruled out a crucial part of the hunting ground for the 'God particle', thought to confer mass on all other matter.
The results suggest that the Higgs boson is not a relatively high-mass particle, and physicists must keep looking for evidence of the Higgs boson in the lower-mass debris that sprays from particle collisions inside the Tevatron.
This means that scientists at the Large Hadron Collider (LHC) at CERN, Europe's particle-physics laboratory near Geneva, Switzerland, won't have a quick route to success. The LHC was designed to collide particles with five times the energy of the Tevatron, and would have excelled at hunting for a high-mass Higgs particle.
"If the Higgs existed at one of those high masses, then they could have anticipated discovering it very quickly," says Darien Wood, a particle physicist at Northeastern University in Boston, Massachusetts, and spokesman for DZero, one of the two main Tevatron experiments. The results are based on all data collected since 2001 by DZero and its sister experiment, the Collider Detector at Fermilab (CDF), which study the debris from proton-antiproton collisions.
Lyn Evans, project leader at the LHC — which is being repaired after it was damaged during start-up tests in September 2008 — says the high-mass regime was the "obvious" place for both the LHC and Tevatron to make headway. That's because there are fewer debris particles with such high energies, making it easier to sift through the data looking for a trace of the Higgs particle.
"The fact that they've excluded the Higgs in this band is going to make it harder for everyone," says Evans.
The Tevatron results specify that the Higgs boson is very unlikely to have an energy between 160 and 170 gigaelectronvolts (GeV). Gigaelectronvolts are a measure of a particle's energy that is proportional to its mass.
Experimentalists have been working on the assumption that the Higgs boson lies somewhere between 114 and 185 GeV. The lower-energy boundary was established by the Large Electron-Positron (LEP) collider at CERN in the 1990s, whereas the upper boundary is a softer limit established by indirect evidence, such as the masses of the top quark and the W boson.
The latest results, and other evidence, suggest that the Higgs boson is hiding at the lower end of this energy scale. But at lower energies, the job of filtering out other debris and finding a rare Higgs event becomes more difficult. Even if the Tevatron runs through 2011 — not yet planned for in year-to-year US budgets — it would only have about a 30% chance of finding evidence for a low-mass Higgs, according to Fermilab talks presented in February at the American Association for the Advancement of Science conference in Chicago, Illinois.
Finding 'evidence' for something, in particle-physics jargon, is a long way from 'discovering' something. The LHC, if it starts operating at the end of this year, should quickly catch up and surpass the amount of data gathered by the Tevatron, giving it a better shot at making a true 'discovery' - with a confidence level of 99.9999%.
There is also the possibility that the Tevatron and the LHC will exclude the Higgs boson across the entire range of expected energies. It may exist at energies higher than 185 GeV, a region that only the LHC can explore. Or it may not exist at all.
Either way, theorists would have to go back to the drawing board and start tweaking the standard model of particle physics, which, along with predicting the Higgs, explains the behaviour of three out of the Universe's four fundamental forces.
And although narrowing the Higgs hunting grounds is important, says Robert Roser, spokesman for the CDF experiment, "we'd rather find it, not exclude it".
Had to post for those who read this article.
I suppose if we knew how they worked, we could glue and unglue matter at te sub atomic level.
The results suggest that the Higgs boson is not a relatively high-mass particle, and physicists must keep looking for evidence of the Higgs boson in the lower-mass debris that sprays from particle collisions inside the Tevatron.If the Higgs gives all matter its mass, then wouldn't all debris with mass contain the Higgs?
It’s above my pay grade.
I sort of have to agree with your argument.
The Higgs “confers” mass and wouldn’t necessarily have mass.
A massless photon would make more sense, which interacts with high energy states.
It seems to me that many have considered a relationship to exist between gravity and electromagnetism over the years, which might be eventually proven at the boson-particle level.
Gravity is definitely a property of mass, and electromagnetism could be represented as a property of energy. It has some properties that resemble gravity. ( With the exception of a repulsive state in gravity, which can’t be demonstrated or proven at present )
It is possible that the Higgs can only be observed in close proximity to a large gravity source or a large energy source, like the LHC, a star or singularity.
Such extreme conditions may be necessary to provide the proper environment needed for the transformation of energy to mass.
At any rate, assuming mass is necessary for the Higgs is probably misdirected. More theoretical research is going to have to be done to determine what the properties are for the Higgs.
IIRC, electromagnetic repulsion and attraction are mediated by photons - but a photon itself has no charge.
Thanks neverdem.
Physicists get closer to finding the ‘God Particle’
AFP on Yahoo | 3/13/09 | AFP
Posted on 03/13/2009 8:04:31 PM PDT by NormsRevenge
http://www.freerepublic.com/focus/f-news/2206301/posts
Single top quark detected
Science News | March 10th, 2009 | Solmaz Barazesh
Posted on 03/13/2009 9:49:17 PM PDT by neverdem
http://www.freerepublic.com/focus/f-news/2206336/posts
· Google ·
If it exists. My money’s on the Tevatron. They are way ahead. An international coallition, think UN, is inherently less efficient.
The “luminosity” of the LHC is MUCH GREATER than that of the Tevatron. Anything of note in the energy range they decide to run the LHC is far more likely to be found by it than by the Tevatron since they will gather data much much faster.
If this doesn't do it for you, I'm afraid I won't be able to help much in a few posts.
Thanks for the link!
It’s broke. My money’s on the Tevatron, if this particle exists.
I’m not so sure they will find it. The Higgs that is.
To paraphrase Bill Clinton, "It depends on what the definition of 'find' is." The positron was "found" by its particle track in a bubble chamber - an electron bending the wrong way. The neutrino was "found" as a missing track, required to be there by conservation of momentum and energy - corroborated of course in a multitude of interactions.
Then we moved on to the Psi particle with a lifetime of 7e-21 seconds, so don't be lookin' for no tracks. This discovery consisted in a "hump" in the cross section of an interaction as a function of energy - a "resonant energy". OK.
Now where are we? Now we require statistical analysis! A certain collection of data gleaned from millions, or billions ( I don't know ) of interactions must depend, with 99.X% certainty on the existence of this particle, so what was that middle part again?
Like Andy Warhol said, "Death is so abstract."
What makes you think that I think that? I think it's so funny that you think that I think that.
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