1.1.11

LHC plans extra year for Higgs hunt : Nature News

Published online 10 December 2010 | Nature | doi:10.1038/news.2010.667

News

LHC plans extra year for Higgs hunt

Collider may run right through 2012 to find elusive particle.

Geoff Brumfiel

ATLAS cavern, installation of Muon chambersThe extra year could be enough for the ATLAS detector to spot the Higgs particle.Claudia Marcelloni / CERN

Scientists are preparing to run the world's largest particle accelerator for an extra year in a bold bid to find the Higgs particle, part of the mechanism that is thought to endow other particles with mass.

If the plan is implemented, the Large Hadron Collider (LHC), located at CERN, near Geneva, Switzerland, will run until the end of 2012 — rather than 2011 — before entering a year-long shutdown for a major upgrade. Preparations for the extended run, which would see the 27-kilometre circular collider operating over three continuous years, are being finalized and are likely to be agreed to by CERN's management and council in January.

The decision comes with the belief that new discoveries may be just around the corner. "It would be a shame to stop," says Steve Myers, who is responsible for maintaining and upgrading the accelerator.

“It would be a shame to stop.”

Steve Myers
CERN

At stake is the particle many physicists see as the LHC's raison d'être: the Higgs. Theorists believe that the Higgs particle, together with its associated field, create a sort of cosmic molasses that endows other particles with mass. The mechanism is seen as a necessary extension to the 'standard model' of particle physics, which presently struggles to explain the origins of mass, and why some particles are heavy whereas others weigh nothing at all.

Higgs hunt

Initially, there were doubts about whether the LHC would be able to find the Higgs at the machine's current energies. Since a major accident in 2008, the LHC has been running at half its design energy. CERN managers had planned a 15-month pause in data collecting at the start of 2012, which would allow the machine to be upgraded to full power.

But now there is a growing consensus that the LHC will be able to cover most of the territory in which a standard Higgs particle might be found, even if it isn't upgraded. The best guess of most physicists is that the Higgs weighs somewhere between 114 and 600 gigaelectronvolts (109 electronvolts), according to Sergio Bertolucci, CERN's director for research and computing. Its mass will determine how the particle decays — and how easily it can be detected.

“If we stop the machine with 3,000 people apiece in the experiments waiting for data, there is no way we could get home at night without having slashed tyres on our cars.”

Sergio Bertolucci
CERN

Paradoxically, a heavier Higgs might be easier to spot, Bertolucci says. That's because the heavy Higgs is likely to decay into pairs of rare, heavy particles known as W and Z bosons. Pairs of Ws or Zs would stand out sharply against the other particles created in LHC collisions. If the Higgs were lighter, its signature would blend into the background, making it much harder to detect and requiring physicists to amass and filter through data from months of collisions.

Despite the challenge, Bertolucci says that he is "very optimistic" that the LHC can cover most of the ground over which the Higgs is expected to be found. The machine has performed exceptionally well since the 2008 accident, and he thinks that it will be able to deliver the quantities of data needed over the 2011-12 running period. In addition, he says, managers think that they can collide particles at 8 teraelectronvolts (TeV; 1012 electronvolts), up from the current 7-TeV energies, but still well below the machine's 14-TeV design energy.

Pushing it

Physicists working on the detectors built to find the Higgs are backing the plan. "My personal opinion is that we should put all the cards on the table," says David Francis, a physicist on the ATLAS detector, one of two giant detectors primarily designed to spot the elusive particle. "The experiments are going well, the accelerator is going well," adds Joe Incandela, a physicist at the University of California at Santa Barbara and deputy spokesman for the CMS detector, the second main detector for Higgs hunting. "Let's really push it to where we can get a meaningful data set to do lots of physics."

ADVERTISEMENT

'); document.write(''); } //-->

Bertolucci says that there are also political reasons to extend the run. The world's second most powerful accelerator, the Tevatron at Fermilab in Batavia, Illinois, is nipping at the LHC's heels, and if it continues to run, might beat the larger accelerator to the Higgs. Moreover, European plans for high-energy physics, as well as a global plan for a next-generation linear collider, are facing big decisions in the coming years and will be greatly influenced by the LHC's results.

But keeping the machine running for an extra year will have consequences. The delicate alignment of the LHC's superconducting magnets could suffer, requiring extra maintenance, says Myers. And additional computing resources will have to be found to handle the flood of extra data produced by the detectors.

Managers recognize the difficulties, but Bertolucci says they have strong incentives to extend the run: "If we stop the machine with 3,000 people apiece in the experiments waiting for data, there is no way we could get home at night without having slashed tyres on our cars."

The decision will be discussed at a meeting in the French town of Chamonix in late January, and should be finalized shortly after. 

Comments

If you find something abusive or inappropriate or which does not otherwise comply with our Terms or Community Guidelines, please select the relevant 'Report this comment' link.

Comments on this thread are vetted after posting.

  • #16683

    Extending its run through 2012 will enable the LHC to play a timely role the predicted end of history on Dec. 21, 2012, as specified in the Mayan calender. Hopefully, we'll all laugh about this in 2013. There remain, however, disturbing and unrefuted scientific reasons to believe that CERN's in-house safety report was a PR whitewash and that the LHC, by potentially generating destructive strangelets and black holes, may be capable of causing global harm.

    International critics groups recently released two extensive and well-documented reports that undermine CERN's safety claims (at LHC-Concern.info and HeavyIonAlert.org). Given the acknowledged uncertainties and planetary stakes, it is unethical for the LHC experiments to proceed – particularly when there is no outside oversight or regulation.

  • #16690

    Why cannot we grasp that mass is more fundamental than pure energy (i.e. its mass is equal to zero)? Pure energies, for example photons, are the excitations of the Einstein spacetime – this spacetime has the MASS DENSITY NOT EQUAL TO ZERO. In the Everlasting Theory, the ground state of the Einstein spacetime is a gas composed of the non-rotating binary systems of neutrinos. Photons are the rotational energies of the binary systems. Vortices of energy transform into mass in the Einstein spacetime because rotational energy decreases local pressure in the Einstein spacetime – from it follows that the binary systems flow into regions with lower pressure. Such inflows increase local mass density so also mass – such is origin of the famous Einstein formula m=E/c^2. This formula is not valid for pure energy in truly empty volume. Photons cannot move in truly empty volume. Energy is an attribute of mass.
    The energy equation applied in the Special Theory of Relativity shows that even energy of a mathematical point moving with infinite speed IS EQUAL TO ZERO. Such points cannot lead to photons so also to mass. Higgs bosons are not in existence.

  • #16730

    Yes. The Higgs does exist.

    "Despite being rather majestic, Boltzmann's deep integration of probabilities into science was adopted by quantum mechanics. It was attacked from the start. The most basic line of attack at the time of Boltzmann's formulation of a statistical interpretation of the thermodynamics was his use of the never-before-seen-measured microscopic "atoms of molecules". Remember Boltzmann advanced his ideas some fifty years before the recognition of atoms by scientist such as Sir J.J. Thomson and Lord Rutherford. Boltzmann's critics were formidable, the finest physicists at the time. Ernst Zermelo, Ernst Mach, and Friedrich Wilhelm Ostwald attacked Boltzman relentlessly. Not because his viewed time as one-way, but because he had the audacity to suggest matter was made of atoms. This group became known as the Vienna Circle of "Logical positivists" and insisted that Science could be conducted only when all the objects of study were seen and understood. Their main objection to Boltzmann was that there was no means of verifying the existence of atoms and molecules, whose behavior lay at the foundation of Botzmann's probability-based version."
    -Into the Cool (Energy, Flow, Thermodynamics and Life)

  • #16743

    is it a race to find higs
    or is it about who is finding it?

    I mean whoever finds it it will cost tax payers a lot searching at 2 places at the world for the same thing.

    I'm guessing the who part is more important, instead of its energy value; because that's how prestigious people are. I hope they can prove tax payers wrong on it, as it has cost a lot so far.

  • #16744

    @ Robert

    Robert, in order for anyone to take this kind of thing seriously, you'd have to demonstrate why there is a difference between collisions created in a particle accelerator versus the much higher energy collisions that are caused by cosmic rays in the atmosphere every day.

    The LHC cannot ever hope to reach the energies of these kinds of collisions, and they've been going on for billions of years, without any catastrophes.

    This is why I roll my eyes when I hear about these 'dangers' of the LHC and other colliders.

  • #16784

    @John Cunningham,
    John,
    No catastrophic incidents? What about "our" own universe and perhaps the infinitive number of other universes that might have been created due to collisions of cosmic particles? Who knows? As space-time is infinitive, "catastrophes" happen forever simply said. When our lights go out one day, who cares about the cause?

  • #16792

    The recent evidence of fourth generation of quark and neutrinos virtually excludes the finding of unique Higgs boson. It's just wasting money of tax payers and risking their lives for nothing.

  • #16815

    The safety argument equating the LHC beams with "cosmic rays in the atmosphere," reprised above by John Cunningham, was admitted to be invalid by CERN itself. In fact, CERN's 2008 public safety report states that "collisions at the LHC differ from cosmic-ray collisions with astronomical bodies like the Earth..." (Par. 7). A crucial difference is velocity, for the magnetically focused head-on collisions at the LHC could slow some of the products to below escape velocity to plague us. Thus, in regard to neutral microscopic black holes, CERN admits: "Those produced by cosmic rays would pass harmlessly through the Earth into space, whereas those produced by the LHC could remain on Earth" (CERN, Safety of the LHC, 2008, Par. 7).

    The higher energies of some cosmic rays would result in a faster exit of the products, which may contribute to the dark matter of the galaxy. The cosmic ray argument was relocated in 2008 to dense neutron stars and white dwarfs, but flaws were found in the new argument as well (see Sec. 4 of paper by German astrophysicist Rainer Plaga at http://arxiv.org/abs/0808.1415v3 ). Moreover, astrophysicists believe that neutron stars consist in part of strange matter, the outcome critics fear for Earth from strangelet production at the LHC.

  • #16837

    Amazing, To put so,so much emotional energy into an outcome that tires and children would be slashed by others in the experiment of no experiment should someone embodied in the process should mis-step or default to a natural position of stasis within the compound to save their career.
    The particle "Understands" your positioning and the test has been completed,actually and the resultant flow is only to stage the next scenario by the system operator.
    Have fun boys,deciding who to deplete,and who to save for the final disposition.

Add your own comment

This is a public forum. Please keep to our Community Guidelines. You can be controversial, but please don't get personal or offensive and do keep it brief. Remember our threads are for feedback and discussion - not for publishing papers, press releases or advertisements.

You need to be registered with Nature to leave a comment. Please log in or register as a new user. You will be re-directed back to this page.

via nature.com

Posted by Unknown at 7:54 PM

No comments:

Post a Comment