A Busy Week at CERN

A week at CERN, the laboratory that hosts the Large Hadron Collider [LHC] (where the Higgs particle was discovered), is always extremely packed, and this one was no exception. It’s very typical that on a given day I’ll have four or five intense one-on-one scientific meetings with colleagues, both theorists and experimenters, and will attend a couple of presentations on hot topics — or perhaps ten, if there’s a conference going on (which is almost always.) Work starts at 9 am and typically ends at 7 pm. And of course I have my own work to do — papers to finish, for instance — so after a break for dinner, I keep working til midnight. Squeezing in time for writing blog posts can be tough under these conditions! But at least it is for very good reasons.

Just this morning I’ve just attended two talks related to a future particle physics collider that people are starting to think seriously about… a collider (currently called T-LEP) that would be built in an 80 kilometer-long [50 mile-long] circular tunnel, and in which electrons and positrons [positron = anti-electron] would be smashed together.  The physics program of such a machine would be quite broad, including intensive studies of the four heaviest known particles in nature: the Z particle, the W particle, the Higgs particle and the top quark. Any one of them might reveal secrets when investigated in detail.  In fact, T-LEP’s extremely precise measurements, made in the 100-500 GeV = 0.1-0.5 TeV energy range, would be used to check the equations that explain how the Higgs field gives elementary particles their masses to one part in a thousand, and to potentially be indirectly sensitive to effects of unknown particles and forces all the way up to 10-30 TeV energy scales.

After that I had a typical meeting with an experimentalist at the CMS experiment, discussing the many ways that one might still make discoveries using the existing 2011-2012 LHC data. The big concern here is that the LHC experimenters are so busy getting ready for the 2015 run of the LHC that they may not fully exploit the data that they already have.

Off to more meetings…

36 responses to “A Busy Week at CERN

  1. Pingback: A Busy Week at CERN | pocket2mail

  2. christopher bolger

    I don’t know the current status of SLAC, for all I know it is a scrap yard, but has anyone thought of upgrading the energies of its former electron-positron collider from the Z0 to the Higgs boson so we can study that in detail, or would it not have enough luminosity for that?

    • Electrons and positrons (being very lightweight) interact very weakly with Higgs particles, so you can’t hope to make Higgs particles in electron + positron –> Higgs. You would have to upgrade the energy not to 125 GeV (from 91) but to well over 220, so you could make a Z plus a Higgs particle via a “virtual Z particle”. That’s completely impossible, given the SLAC machine’s design, so no one ever considered this. And even if you could, the rate would still be far too low to be useful. You need a much more rapid-fire machine.

  3. “Old” particle accelerators like SLAC have a long life after they are no longer “useful” for its original purpose: they are very useful as sources of synchrotron radiation, that is, generators of high energy photons.

    In fact, SLAC has played an important part in the unveiling of the secrets hidden in the Archimedes Palimpsest, so, now we know much more about what really did Archimedes write in his “papers”.

    Kind regards, GEN

  4. Thanks for this link “how the Higgs field gives elementary particles their masses” that I had missed before ! :-)
    The basic idea is so simple yet effective!
    … but the devil hides in the (relativistic) details…
    As a programmer, I’d quote Hoare: “There are two ways of constructing a software design: One way is to make it so simple that there are obviously no deficiencies, and the other way is to make it so complicated that there are no obvious deficiencies. The first method is far more difficult. It demands the same skill, devotion, insight, and even inspiration as the discovery of the simple physical laws which underlie the complex phenomena of nature.”
    Welcome in Europe, Matt

    • /One way is to make it so simple that there are obviously no deficiencies, and the other way is to make it so complicated that there are no obvious deficiencies. /- well said Mr Giulio.

      The mass energy relation in quantum mechanics and relativity have different philosophical point of origin. But they were originated from some unexplained in classical mechanics from europe (Germany). But they never represented their philosophical origin (jewish or Indian).
      Einstein was more German than jewish. In India nobody was thought the Quantum realm. It was Egyptian, it was Persian, then they said Indian. Like the notion of Confucianism, the term Hindu thought itself was coined by Europeans.

      The mass-energy relation L (THE RESTMASS) = potential energy – kinetic energy. This is a simple mechanics.
      Without this rest mass quantum mechanics and relativity cannot survive. Eventhough there is Quantum tunnelling and Time dilation – in 100 nanometers or less or in expanding universe – The basic idea (enlightenment) is so simple yet effective!

      “It demands the same skill, devotion, insight, and even inspiration as the discovery of the simple physical laws which underlie the complex phenomena of nature.”

      • Btw, “quantum tunneling is important to test the validity of the quantum mechanics on scales larger than the atomic one”

        • Sorry Mr Giulio, Iam not an expert. But I understand, in macro level the Quantum realm have particle reality (paradox), in which relativity can takeover. The “Quantum action (h)” in atomic scale is effective – but could not be interpreted in macro level – otherwise we have reconciliation with relativity.

          The quantized angular momentum have the “mass energy”, so the gauge field, like in classical mechanics, the time integral of the Lagrangian have the action (s) – which is the mass energy = L (E in einsteins equation).
          Here the Lagrangian in quantum physics is adjusted to relativity trick as Lagrangian density because of the particle nature paradox at macro level. ?

          At first the quantum action was referred to heat, so the gauge field particle photon have mass energy (so we have laser) – so in standard model, higgs particles can give the electron its mass via relative parameters.

          But this cannot be the case in proton mass, in which gluon fields have no mass energy (vacuum energy?). They have only relative mass. Without rest mass there is no inertia.

          Noether’s theorem, which connects physically conserved quantities (L) to continuous symmetries of a physical system (inertia).

          The assumption that photons are not subjected to gravity, is wrong – they have an energy, so they have also a mass (just no rest mass). Otherwise, there is also no light deflection in the gravitational field of the Sun.
          This will be more subtle when come to gluons.

          • I think we get conservation of momentum from symmetry of translation and conservation of energy (so whay you mean by rest mass maybe), as a result of symmetry under time translation. Anyway a lot of functional analysis (Hilbert/Banach space, Lorentz transformation, etc…) is preliminary to pysical equations (Einstein-de Broglie formula, etc…)
            My point here, out of curiosity, is the way they are going to check the “Higgs” equations at T-LEP: in fact I can easily believe that theare are “many ways that one might still make discoveries using the existing 2011-2012 LHC data”…

      • “Einstein was more German than jewish”.

        Your sense of humor is irresistible.

        Could you please go read first some elementary texts in physics and history of physics before drowning this blog entry with crackpot comments?

  5. I’m very interested in this, and do follow the threads, but even I have to question as to much all this will cost and if this can be justified, and I suppose how much is needed to be known to run our Human interests ?

    Yes, I know, I know unless you know the full picture, who knows what’s possible.
    Budgets are being cut !

    Walter

    • “I’m very interested in this, and do follow the threads, but even I have to question as to much all this will cost and if this can be justified, and I suppose how much is needed to be known to run our Human interests?”

      It isn’t what is needed to be known to run our Human interests. We already have that info. We don’t apply it very often, as it would involve replacing dozens of dictatorships with democracies, abolishing all war on the planet, etc. Things that are not likely to happen… at least while we are still half savage.

      Rather, it is what is needed to satisfy human curiosity. And that, in my opinion, requires no justification – it is simply part of the human condition that cannot be denied, and neglecting it comes at a terrible price: The stalling of human progress.

      Yes it’s a time of budget cuts but that doesn’t mean everything should be cut. It is never smart to cut basic research, perhaps penny-wise but definitely pound- foolish. There are many government programs that need to be cut or modified, but the planets next great collider (be it T-LEP or muon) should not be one of them. Anyway, we are talking about a machine that will not come on line until the mid 2020’s.

  6. I would love to visit this place and meet some people involved with it all because to me, there is no greater discovery than this..

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  8. I think it will be a tough thing to build a 80 km long circular tunnel. It will be very expensive and hard to convince funding peoples (see the example of SSC).
    The main argument of LHC was that it was reusing the LEP tunnel, so avoiding the costs of building a new one.
    I think the idea of Carlo Rubia to buid a muon collider for a Higgs factory is very attractive, as the tunnel would be much smaller, even if working with such decaying particles has never been done (relativity should help at big energies), and there are certainly hard technical difficulties to solve.

  9. Avoiding off topic posts about philosophical point of views, my comment was about the equations in the paragraph “Enter the Higgs Field: The Right Equations for the Electron’s Mass”, that admittedly “become a little more tricky”…
    To me, it is quite understandable the need of double checking those equations against extremely precise measurements (but only observable quantities – and not “gauge” fields – can be measured experimentally).
    “A scientific theory should be as simple as possible, but no simpler.”
    The SM is way too complicated

  10. SM is as simple as the segment of reality it attempts to describe.

    This is what Occam’s Razor deals with.

    Kind regards, GEN

  11. Copernicus would have said the same about his epicycles, wouldn’t he? :-)

    • Err… this is egregiously off-topic now, but, Guilio, I think you’ll find that epi-cycles are (post-) Ptelemaic and Copernicus’ helio-centric theory neatly disposed of them, with confirmation/development from Brahe, Kepler and on to Newton. In summary: No, Copernicus wouldn’t…

      • Yep… On the topic of the CNR Projects related to the Higgs bison you will also find other comment like this:
        The relevant question is: Do we keep adding epicycles to the faltering aged paradigm, or do we begin the search for a revolutionary new paradigm that can make definitive predictions, that can be experimentally verified, and that can provide simple and natural answers to fundamental problems?

  12. Particles have momentum, not matter what, even if they don’t have rest mass, like say, photons.

    Anything that has momentum will interact with inertia, even if it does not have rest mass.

    So, there is no inconsistency with the fact that inertia may affect photons.

    In a way, this aspect of particles having momentum and being able to interact with inertia was the starting point that allowed Einstein to start working on GR: the equivalence between acceleration and gravity.

  13. We know from classical mechanics that force is the time derivative of momentum.

    Any change in momentum over time will give rise to a force exerted on the body in question, even if it is a point-like body, like an electron or a photon.

    As momentum is a vector, the change in momentum over time could be any change in the parameters of a vector: its magnitude, or its orientation, or its direction.

    We also know that the force exerted on the body will be normal (perpendicular) to the velocity of the body (this is a conservation law).

    From relativity, we also know that the equation of the force must be invariant for all reference frames.

    As long as a particle has momentum and if such momentum changes over time, there will be a force exerted on the particle even if it does not have rest mass: this is mostly a classical mechanics definition, but it has its own equivalence in relativity.

    One of the links between classical mechanics definitions of forces and its equivalence in GR is through the principle of Action.

    Kind regards, GEN

  14. /I think we get conservation of momentum from symmetry of translation and conservation of energy (so whay you mean by rest mass maybe), as a result of symmetry under time translation./– Giulio.

    /Particles have momentum, not matter what, even if they don’t have rest mass, like say, photons.
    Anything that has momentum will interact with inertia, even if it does not have rest mass.
    So, there is no inconsistency with the fact that inertia may affect photons.
    In a way, this aspect of particles having momentum and being able to interact with inertia was the starting point that allowed Einstein to start working on GR: the equivalence between acceleration and gravity./- Gastón E. Nusimovich.

    The fact of Energy Conservation is that, everything runs because of energy. Even time runs if there is energy. Time runs slower if there is less energy and time runs faster if there is more energy. Just like a clock runs faster if there is more energy in the spring.
    If nature runs out of energy time runs slow and if it gains energy time runs faster. That is the only idea behind time dilation.

    The clocks in nature are not a constant rate clocks. BUT THE “RELATIVE” INERTIA IS CONSTANT. Energy is more fundamental than time. Energy is physical and time is information. But energy is not a constant (changes with time). Energy is conserved because of constancy of “inertia”. ?

    So… “THE PHYSICAL REALITY OF TIME DILATION AND REST MASS CANNOT COEXIST !”

  15. @veeramohan: According to GR, any concentration of momentum and/or energy will make close-by clocks to run slower, not faster, so, it is the other way around.

    Time dilation is the result of the finite, constant and universal magnitude of the speed of electromagnetic radiation as measured from any reference frame, and even though energy has a role in the process of time dilation, it is not according to the mechanism that you are describing.

    Kind regards, GEN

    • More energy more faster the time ?
      In GR creation of mass (concentration of momentum/energy) by angular momentum (gravity?) make the close-by (localised?) clocks to run slower (unnaturalness?).

      Speed of light “c” (electromagnetic radiation) is not a constant, the “relative” inertia is constant (geodesic?)- but we cannot measure this phenomenon – only speed of light as reference frame (constant) measurements are possible – it is a trick ? .
      So there is no meaning for rest mass, when energy changes with time. The inertia have an almost non repeating pattern (constancy) – like weather pattern – so there is a possibility of proton decay. ?

      /The basis of spectrometry is that natural clocks are constant/
      Again we use the same method to “measure” the phenomenon of “aging” ?

  16. What is described as inertia in classical (Newtonian) mechanics, for GR is that any body, no matter its condition of movement, always stays in its own world-line or geodesic, which happens to be a line in the 4-dimensional manifold of space-time.

  17. the basis of atomic clocks is that natural clocks are constant, even though the measurements can be affected by relativity as we know.

    The basis of spectrometry is that natural clocks are constant, even though the measurements can be be affected by relativity as we know.

    We can detect the expansion of our universe because we can measure the z factor from radiation coming from faraway sources. The z factor that we measure is the result of the comparison of the wavelength coming from the faraway source and the wavelength of the same kind of radiation we measure here on Earth.

    We can make this comparison to obtain the z factor because natural clocks are constant.

    Kind regards, GEN

  18. The fact that natural clocks are constant is what makes them useful as clocks!

  19. The speed of light “c” have maximum speed because, there is almost no mass energy. It produce heat (electromagnetic radiation) because there is some mass energy, with reference to it’s own speed – and that is measurable. At the total abscence of localized mass energy, the vacuum energy will travel very fast at very short distance due to it’s energy content ?

    • The speed of light “c” have….the speed of light “c” has !

      How can the speed of light have maximum speed?

      “Because there is almost no mass energy”…no physical content in your statement!

      Heat is NOT electromagnetic radiation!

      “It produce heat (electromagnetic radiation) because there is some mass energy, with reference to it’s own speed – and that is measurable. At the total abscence of localized mass energy, the vacuum energy will travel very fast at very short distance due to it’s energy content ?”…again, nothing but sheer nonsense!

      Please stop polluting this site with your incoherent babbling!

      • Mr Nonsense,
        I wrore this from a 2007 i Phone, while travelling on a bumpy road. I want to delete it, but there is no option.

        I tried to say (or ask) the difference between vacuum energy and mass energy.

        Thermal radiation is electromagnetic radiation generated by the thermal motion of charged particles in matter. All matter with a temperature greater than absolute zero emits thermal radiation.
        Light is an electromagnetic wave. light creates an electromagnetic field by it self for transmit.

        Historically, the derivation of the strange properties of C (relativity) relies on a pretty straight forward piece of Einsteinian logic, based in part on an understanding of light.

        1) All the laws of physics work the same, whether you’re moving or not. There is no experiment that can tell you whether or not you’re moving.-the “relative” inertia is constant (geodesic?).

        2) Light is an electromagnetic wave, and the velocity of these waves can be derived from Maxwell’s laws.

        3) Maxwell’s laws, like all physical laws, are independent of how fast you’re moving. So the speed of light must also be independent of how fast you’re moving.

        4) So, there exists a speed (the speed that light travels at) that is the same to everyone, no matter how fast they themselves are moving. Axiomatically, There’s your special relativity!

        So why is C the fastest speed?
        A good way to think of it is to first ask; how do you know when you’re moving faster than something else? If you’re driving down the highway and you’re moving faster than the car in front of you, then eventually you’ll pass that car. However, C is the same to everyone, no matter what. So, say a photon goes past you, and you try to catch up. But no matter how much you speed up, the photon will always be moving away at the speed of light. You can never catch up (or even come close to starting to catch up). So, regardless of perspective, the photon is always moving faster than you.
        Some of this may seem seem contradictory, but surprisingly, it’s all self consistent (Localised). Very surprisingly. ???

  20. This is one of the worst nonsense I ever read on Relativity and Physics in general.

    • Sorry, as I understand (may be nonsense), the Higgs particle is a “ball” on the spring. But by QM particle is the density of the excited spring thread – the localized ripple of the field – in which the space in between the spring threads (vacuum energy) also equally influence. My understanding is, with the history of Relativity, can define only the particle nature (ball) – not the changing densities. The virtual particles make the difference negligible because, of the relative inertia (geodesic in GR) – almost the constancy ?

      • Veeramohan,
        You are deeply confused about Physics in general. It is abundantly clear that you are arbitrarily mixing and matching various concepts without having a clear understanding of what they mean in the first place. Do yourself a favor and take a Physics 101 introductory course before cluttering this blog with nonsensical sentences.

        • we destroyed the energy conservation inside an atom (shortest distance) and got the nuclear explosion. What about distroying the energy conservation at “zero point energy” – distroying the rest mass – creating new space ?

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