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  • richardmitnick 1:20 pm on March 12, 2015 Permalink | Reply
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    From Don Lincoln at FNAL: The Detectors at the LHC 

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    Fermilab is an enduring source of strength for the US contribution to scientific research world wide.

    The Large Hadron Collider or LHC is the world’s biggest particle accelerator, but it can only get particles moving very quickly. To make measurements, scientists must employ particle detectors. There are four big detectors at the LHC: ALICE, ATLAS, CMS, and LHCb. In this video, Fermilab’s Dr. Don Lincoln introduces us to these detectors and gives us an idea of each one’s capabilities.

    CERN LHC Map
    CERN LHC Grand Tunnel
    CERN LHC particles

    CERN ALICE New II
    ALICE

    CERN ATLAS New
    ATLAS

    CERN CMS New
    CMS

    CERN LHCb New II
    LHCb

    See the full article here.

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    Fermilab Campus

    Fermi National Accelerator Laboratory (Fermilab), located just outside Batavia, Illinois, near Chicago, is a US Department of Energy national laboratory specializing in high-energy particle physics. Fermilab is America’s premier laboratory for particle physics and accelerator research, funded by the U.S. Department of Energy. Thousands of scientists from universities and laboratories around the world
    collaborate at Fermilab on experiments at the frontiers of discovery.

     
  • richardmitnick 10:52 am on February 19, 2015 Permalink | Reply
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    From FNAL: “Physics in a Nutshell How many forces?” 

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    Fermilab is an enduring source of strength for the US contribution to scientific research world wide.

    Thursday, Feb. 19, 2015
    FNAL Don Lincoln
    Don Lincoln

    1
    Unlike in Star Wars, where there was but one force with a light and dark side, the number of fundamental forces is a much murkier question.

    If you’ve read many of my columns, you know quite a bit about the Standard Model.

    3
    The Standard Model of elementary particles (more complete depiction), including the Higgs boson, the three generations of matter fields, and the gauge bosons, as well as their properties and interactions, and the effect of spontaneous electroweak symmetry breaking by the Higgs field.

    You know that there are quarks and leptons. You’ve heard about the gluon, the W and Z bosons, the photon and the graviton. And you know that this means that there are four fundamental forces: the strong and weak nuclear forces, electromagnetism, and gravity. Easy peasy.

    However, the reality is actually a lot murkier: Not all forces are independent. For instance, back in the 1830s, scientists knew of two distinct forces: electricity and magnetism. But when Maxwell wrote down his equations for electric and magnetic forces in the 1860s, it became clear that the two were really one force, electromagnetism.

    Similarly, in the late 1960s, physicists mathematically unified the electromagnetic and weak forces and showed that there was just one electroweak force. Under this reasoning, there are only three forces in nature: strong, electroweak and gravity.

    But then the Higgs boson was discovered in 2012, indicating yet another force, specifically the Higgs force. So now we’re back up to four. On the other hand, the Higgs mechanism is the phenomenon that makes the weak force and electromagnetism appear to be different. So maybe it’s tied in with the electroweak force. That statement is as much speculation as theory, but it would bring the number of fundamental forces back down to three.

    And then there is the hope of physicists to unify the electroweak force and the strong force into a single grand unified theory, or GUT. This would reduce the force count to two: the electroweak-strong-Higgs force and the gravitational force. We physicists are an ambitious lot, and we eventually hope to invent a theory of everything or TOE, which would unify GUT and gravity. This would leave us with but a single force, and the apparent fundamental forces would just be different manifestations of the one primordial force.

    So where does that leave us? Well, it’s probably safe to talk of five fundamental forces (strong, weak, electromagnetism, gravity and Higgs) and probably more accurate to speak of four (strong, electroweak, gravity and Higgs). But physicists are constantly trying to figure out the fundamental rules of the universe, and perhaps we are just a clever thought or two away from reducing that count further.

    The bottom line is that giving a number requires that you know what you are doing and what assumptions you are making. Physics, like all science, is a fluid endeavor and changes as our understanding improves. It’s not the number that matters, but rather knowing what the number means. Unless we’re talking lottery numbers. Then you better get it right.

    See the full article here.

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  • richardmitnick 2:47 pm on January 23, 2015 Permalink | Reply
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    From Symmetry: “Superconducting electromagnets of the LHC” 

    Symmetry

    January 23, 2015

    FNAL Don Lincoln
    This article was written by Don Lincoln, Fermi National Accelerator Laboratory

    You won’t find these magnets in your kitchen.

    1
    Photo by Maximilien Brice, CERN

    Magnets are something most of us are familiar with, but you may not know that magnets are an integral part of almost all modern particle accelerators. These magnets aren’t the same as the one that held your art to your parent’s refrigerator when you were a kid. Although they have a north and south pole just as your fridge magnets do, accelerator magnets require quite a bit of engineering.

    When an electrically charged particle such as a proton moves through a constant magnetic field, it moves in a circular path. The size of the circle depends on both the strength of the magnets and the energy of the beam. Increase the energy, and the ring gets bigger; increase the strength of the magnets, the ring gets smaller.

    The Large Hadron Collider is an accelerator, a crucial word that reminds us that we use it to increase the energy of the beam particles. If the strength of the magnets remained the same, then as we increased the beam energy, the size of the ring would similarly have to increase. Since the size of the ring necessarily remains the same, we must increase the strength of the magnets as the beam energy is increased. For that reason, particle accelerators employ a special kind of magnet.

    CERN LHC Map
    CERN LHC Grand Tunnel
    CERN LHC particles
    LHC at CERN

    When you run an electric current through a wire, it creates a magnetic field; the strength of the magnetic field is proportional to the amount of electric current. Magnets created this way are called electromagnets. By controlling the amount of current, we can make electromagnets of any strength we want. We can even reverse the magnet’s polarity by reversing the direction of the current.

    Given the connection between electrical current and magnetic field strength, it is clear that we need huge currents in our accelerator magnets. To accomplish this, we use superconductors, materials that lose their resistance to electric current when they are cooled enough. And “cooled” is an understatement. At 1.9 Kelvin (about 450 degrees Fahrenheit below zero), the centers of the magnets at the LHC are one of the coldest places in the universe—colder than the temperature of space between galaxies.

    Given the central role of magnets in modern accelerators, scientists and engineers at Fermilab and CERN are constantly working to make even stronger ones. Although the main LHC magnets can generate a magnetic field about 800,000 times that generated by the Earth, future accelerators will require even more. The technology of electromagnets, first observed in the early 1800s, is a vibrant and crucial part of the laboratories’ futures.

    See the full article here.

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    Symmetry is a joint Fermilab/SLAC publication.


     
  • richardmitnick 3:39 pm on January 21, 2015 Permalink | Reply
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    From Don Lincoln at FNAL: “GUTS and TOES” 

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    Fermilab is an enduring source of strength for the US contribution to scientific research world wide.

    Albert Einstein said that what he wanted to know was “God’s thoughts,” which is a metaphor for the ultimate and most basic rules of the universe. Once known, all other phenomena would then be a consequence of these simple rules. While modern science is far from that goal, we have some thoughts on how this inquiry might unfold. In this video, Fermilab’s Dr. Don Lincoln tells what we know about GUTs (grand unified theories) and TOEs (theories of everything).

    Watch, enjoy, learn.

    See the full article here.

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  • richardmitnick 2:39 pm on December 5, 2014 Permalink | Reply
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    From FNAL- “Frontier Science Result: CMS Precisely measuring nothing” 


    Fermilab is an enduring source of strength for the US contribution to scientific research world wide.

    Friday, Dec. 5, 2014

    FNAL Don Lincoln
    Don Lincoln

    The CMS detector is a technical tour de force. It can simultaneously measure the passage of electrons, pions, muons, photons and all manner of particles, both short-lived and long-lived.

    CERN CMS New
    CMS at The LHC at CERN

    However, there are some particles that simply don’t interact very much with matter. These include neutrinos and some hypothetical long-lived and weakly interacting particles that may appear in collisions that probe supersymmetry, extra dimensions of space and dark matter. The CMS detector simply doesn’t see those kinds of particles.

    m
    Collisions like these indicate the existence of invisible particles. The blob of color in the upper left hand corner shows where particles were knocked out of the collision to deposit energy in the detector. The fact that we see no balancing energy in the lower right hand corner means that an invisible particle has escaped the detector. As the number of simultaneous collisions in the LHC increases, it will become increasingly difficult to study this kind of physics.

    Supersymmetry standard model
    Standard Model of Supersymmetry

    That sounds like a terrible oversight, but the reality is more comforting. We can use physical principles of the kind taught in high school physics classes to identify collisions in which these particles are made. Essentially, we see them by not seeing them.

    In the first semester of physics, we learn about a quantity called momentum and how it is conserved, which means it doesn’t change. In the classical world, momentum is determined by multiplying an object’s mass and velocity. In the world of relativity and particles, the definition is a bit different, but the basic idea is the same and the principle that momentum is conserved still applies.

    Prior to a collision, particles travel exclusively along the beam direction. This means that before the beam particles collide, there is no momentum perpendicular to the beams, or what scientists call transverse momentum. According to the laws of momentum conservation, there should be zero net transverse momentum after the collision as well. If we sum the transverse momentum of all particles coming out of the collision, that’s what we find.

    However, when there are undetectable particles, the measured transverse momentum is unbalanced. Scientists call the unobserved transverse momentum missing transverse energy, or MET. MET is a clear signature of the existence of one or more invisible particles. Accordingly, it is important to measure carefully the transverse momentum of all observable particles.

    Particle experiments have been employing this technique for decades, but few experiments have operated in the challenging collision environment that exists at the LHC. Any time the beams pass through one another, typically dozens of collisions between beam particles occur. Most often, one of those collisions involve some “interesting” process, while the others usually involve much lower-energy collisions. However, those low-energy collisions still spray particles throughout the detector. The existence of these extra particles confuse the measurement of MET and make it tricky to know the exact momentum of the invisible particles.

    CMS scientists have worked long and hard to figure out how to mitigate these effects and recently submitted for publication a paper describing their algorithms. With the impending resumption of operations of the LHC in the spring of 2015 (which could involve as many as 200 simultaneous collisions), researchers will continually revise and improve their techniques.

    See the full article here.

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  • richardmitnick 8:10 pm on December 1, 2014 Permalink | Reply
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    From Scientific American- Don Lincoln of Fermilab “U.S. Particle Physics Program Aims for the Future” 

    Scientific American

    Scientific American

    November 25, 2014

    FNAL Don Lincoln
    Dr. Don Lincoln

    n the last few years, stories have abounded in the press of the successes of the Large Hadron Collider, most notably the discovery of the Higgs boson. This has led some to speculate that European research is ascendant while U.S. research is falling behind. While there is no argument that U.S. particle physics budgets have shrunk over the past decade, it is also inarguable that America is still huge player in this fascinating research sector, collaborating on projects in Europe and Asia while pursuing a strong domestic program as well.

    CERN LHC Map
    CERN LHC Grand Tunnel
    CERN LHC particles
    LHC at CERN

    To properly appreciate the breadth of the U.S.’s contribution to particle physics research, one must distinguish between the international program and the domestic one. The international program is currently (and appropriately) focused mostly on the LHC. The ring-shaped collider is, without a doubt, an amazing piece of equipment. It is 17 miles around, took a quarter century to plan and build, cost about $10 billion, and requires about 10,000 scientists to operate and study the data it generates. Four distinct experiments (ALICE, ATLAS, CMS and LHCb) were built to use the LHC to investigate some of mankind’s oldest scientific questions.

    CERN ALICE New
    ALICE

    CERN ATLAS New
    ATLAS

    CERN CMS New
    CMS

    CERN LHCb New
    LHCb

    Physicists employed by U.S. universities and national laboratories comprise about a third of the LHC experimental program, making the U.S. the single largest country involved in the project. Although the CERN laboratory itself employs more LHC scientists than any other single institution, America’s Fermilab and Brookhaven National Laboratory are uncontested seconds for CMS and ATLAS, respectively. American physicists lead many analysis efforts and the CMS collaboration even elected Professor Joe Incandela of the University of California, Santa Barbara to be the group leader.

    fnal
    Fermilab’s Main Ring and Main Injector as seen from the air. (Credit: Reidar Hahn/Fermilab)

    While there is no denying the attractiveness of the LHC as a scientific opportunity, U.S. scientists also pursue an active and vibrant U.S. domestic program. Fermilab serves as the hub for the American particle physics community and the laboratory’s accelerators, both present and future, are helping scientists blaze new trails into the fascinating subatomic world.

    Because the LHC is firmly ensconced as the highest energy facility in the world for the foreseeable future, Fermilab is focusing on a different technique to delve into the fundamental rules of the universe. By choosing to concentrate on making the highest intensity particle beams ever achieved, the U.S.’s domestic program is able to investigate some of the rarest phenomena ever imagined at energy scales that far exceed those accessible at the LHC. High energy means that individual beam particles are moving at unprecedented speeds, while high intensity means many particles focused on a tiny area, much like a magnifying lens can focus light. When many particles are brought into tight proximity, there is a small chance that a quantum mechanical fluctuation will allow an extremely unlikely and ultra-high energy interaction to occur.

    It’s easy to explain to people why building a higher energy facility is valuable, but understanding why higher intensity beams is a leading research strategy is a little more difficult and requires two insights. The first and simpler insight is to realize that in particle physics, we look for rare collisions between beams of particles. The reason we look for rare ones is that the common ones have been studied already.

    bnl
    The central campus of Brookhaven National Laboratory. The National Synchrotron Light Source II, under construction at the time of this photo, is at bottom, right. The 3.8-kilometer circumference ring of the Relativistic Heavy Ion Collider can be seen in the distance at the top of the frame. (Credit: Brookhaven National Laboratory)

    To observe the rarest collisions, one must simply make a lot of collisions and wait. It’s similar to trying to win the lottery. If you buy one ticket, you are unlikely to succeed, but if you buy many tickets there is a much higher chance that you have bought a winner.

    The more subtle insight hinges on the principles of physics, specifically quantum mechanics. While it is a firm rule of classical physics that energy is conserved, this rule is not so rigidly observed in the quantum realm. According to the tenets of the Heisenberg Uncertainty Principle, energy can simply appear, as long as it disappears quickly enough. Further, the larger the temporary energy imbalance, the shorter the duration. Thus, because they persist for so short a time, the large energy imbalances are very rare. And, as I have noted above, to study very rare processes, one must employ very intense beams.

    Using the current Fermilab accelerator complex, physicists are studying the interactions of neutrinos with matter. Neutrinos only experience the weak nuclear force and can pass through a lot of matter without interacting. To give a sense of scale, the sun constantly emits neutrinos. If we were determined to stop half of them, we’d need a wall composed of solid lead that is five light years thick! Given this reluctance to interact, the only way to ensure enough neutrino interactions to study is to generate incredibly intense beams and analyze them with massive particle detectors.

    The Fermilab MINOS and NOvA experiments shoot unprecedentedly bright beams of neutrinos from Chicago to northern Minnesota to study an interesting phenomenon called neutrino oscillations. Neutrinos are unique in that they can change their identity, vaguely as if an electron could change into a proton and back. It is hoped that understanding this oscillatory behavior might explain why the universe is made solely of matter when we believe that matter and antimatter existed in equal quantities when the universe began.

    FNAL NOvA
    FNAL NOvA

    mu
    The muon g-2 storage ring arrives at Fermilab, near Chicago, in July 2013 after a cross-country trip from Brookhavn National Laboratory on Long Island, New York. (Credit: Reidar Hahn/Fermilab)

    A second bright star in the constellation of U.S. particle physics research is the use of Fermilab’s accelerator complex to study muons, the heavy cousins of electrons. Scientists of the Muon g-2 experiment will measure the magnetic moment of muons. Earlier measurements at the Brookhaven National Laboratory were very precise – with eight digits of precision. However, there is a tantalizing tension between data and theoretical predictions. While both measurement and prediction are exquisitely precise, the two numbers disagree slightly. This disagreement is small, but is about three and a half times larger than the combined experimental and theoretical uncertainty. This discrepancy could signify the onset of new physics, which could involve supersymmetry, muon substructure or something entirely unexpected. Because Fermilab can generate more intense beams of muons than Brookhaven, the g-2 apparatus was moved from Long Island, New York to Chicago to investigate this question more thoroughly.

    Supersymmetry standard model
    Standard Model of Supersymmetry

    Yet another interesting question that has been investigated relates to unconventional muon decays. Most muons decay into electrons and two neutrinos, however there are reasons to suspect that perhaps muons might decay into electrons without neutrinos. The Mu2e experiment at Fermilab is scheduled to start recording data in a couple of years and this experiment will be sensitive to energy scales far higher than the LHC can achieve. Since neutrinos transform into other types of neutrinos and quarks can change into other quarks, physicists think that the transition of muons into electrons might be possible. Because this decay is expected to be very rare (if it exists at all), this is another reason to make high intensity muon beams.

    A multi-year study of the pressing physics questions by the entire U.S. particle physics community resulted in a firm recommendation to upgrade the Fermilab accelerator complex to further increase the amount of beam it can supply. Thus, the long term plan for the Fermilab laboratory is to increase the intensity of its neutrino beams by at least 50 percent and shoot these beams off to a detector to be located in South Dakota. Because neutrinos change their identity (i.e. oscillate) in flight, having detectors at different distances from Fermilab gives a complementary view of neutrino oscillations and it will shed more light on the phenomenon.

    FNAL LBNE

    But the U.S. community hasn’t forgotten the energy frontier. Eventually, there will be an accelerator that replaces the LHC as the energy leader. It will be a long time before any decisions are made on where that facility might be located (or even what kinds of beams will be needed: protons or electrons). But, to be prepared, several institutions across the U.S. are expanding their accelerator development programs. Whether the future facility is located in the U.S., Europe or Asia, U.S. accelerator scientists will be heavily engaged in developing the required technology.

    Even with tight budgets, the American particle physics community has continued to have a huge impact in humankind’s investigations of some of the oldest scientific questions, and continued support is key to maintaining this leading role.

    See the full article here.

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    Scientific American, the oldest continuously published magazine in the U.S., has been bringing its readers unique insights about developments in science and technology for more than 160 years.

     
  • richardmitnick 8:14 pm on November 24, 2014 Permalink | Reply
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    From FNAL- Video: Dr Don Lincoln on Cosmic Inflation 


    Fermilab is an enduring source of strength for the US contribution to scientific research world wide.

    In 1964, scientists discovered a faint radio hiss coming from the heavens and realized that the hiss wasn’t just noise. It was a message from eons ago; specifically the remnants of the primordial fireball, cooled to about 3 degrees above absolute zero. Subsequent research revealed that the radio hiss was the same in every direction. The temperature of the early universe was uniform to at better than a part in a hundred thousand.

    And this was weird. According to the prevailing theory, the two sides of the universe have never been in contact. So how could two places that had never been in contact be so similar? One possible explanation was proposed in 1979. Called inflation, the theory required that early in the history of the universe, the universe expanded faster than the speed of light. Confused? Watch this video as Fermilab’s Dr. Don Lincoln makes sense of this mind-bending idea.

    Watch, enjoy, learn.

    See the full article here.

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  • richardmitnick 10:31 am on October 31, 2014 Permalink | Reply
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    From FNAL- “Frontier Science Result: CMS Boosted W’s” 


    Fermilab is an enduring source of strength for the US contribution to scientific research world wide.

    Friday, Oct. 31, 2014

    FNAL Don Lincoln
    Don Lincoln

    Today’s article covers an interesting topic. It’s interesting not because it explores new physics, but because of how it reveals some of the mundane aspects of research at the LHC. It also shows how the high energy of the LHC makes certain topics harder to study than they were during the good old days at lower-energy accelerators.

    At the LHC, quarks or gluons are scattered out of the collision. It’s the most common thing that happens at the LHC. Regular readers of this column know that it is impossible to see isolated quarks and gluons and that these particles convert into jets as they exit the collision. Jets are collimated streams of particles that have more or less the same energy as the parent quark or gluon. Interactions that produce jets are governed by the strong force.

    map
    In the green region, we show what a W boson looks like before it decays. Moving left to right, the boson is created with more and more momentum. In the yellow region, we repeat the exercise, this time looking at the same W boson after it decays into quarks, which have then turned into jets. Finally in the pink region, we look at a jet originating from a quark or gluon. This looks much like a high-momentum W boson decaying into quarks. Because ordinary jets are so much more common, this highlights the difficulty inherent in finding high-momentum W bosons that decay into jets.
    No image credit

    Things get more interesting when a W boson is produced. One reason for this is that making a W boson requires the involvement of the electroweak force, which is needed for the decay of heavy quarks. Thus studies of W bosons are important for subjects such as the production of the top quark, which is the heaviest quark. W bosons are also found in some decays of the Higgs boson.

    A W boson most often decays into two light quarks, and when it decays, it flings the light quarks into two different directions, which can be seen as two jets.

    But there’s a complication in this scenario at the LHC, where the W bosons are produced with so much momentum that it affects the spatial distribution of particles in those two jets. As the momentum of the W boson increases, the two jets get closer together and eventually merge into a single jet.

    As mentioned earlier, individual jets are much more commonly made using the strong force. So when one sees a jet, it is very hard to identify it as coming from a W boson, which involves the electroweak force. Since identifying the existence of W bosons is very important for certain discoveries, CMS scientists needed to figure out how to tell quark- or gluon-initiated jets from the W-boson-initiated jets. So they devised algorithms that could identify when a jet contained two lumps of energy rather than one. If there were two lumps, the jet was more likely to come from the decay of a W boson.

    CERN CMS New
    CMS

    In today’s paper, CMS scientists explored algorithms and studied variables one can extract from the data to identify single jets that originated from the decay of W bosons. The data agreed reasonably well with calculations, and the techniques they devised will be very helpful for future analyses involving W bosons. In addition, the same basic technique can be extended to other interesting signatures, such as the decay of Z and Higgs bosons.

    See the full article here.

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  • richardmitnick 12:56 pm on October 3, 2014 Permalink | Reply
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    From FNAL- “Frontier Science Result: CMS Subatomic hydrodynamics” 


    Fermilab is an enduring source of strength for the US contribution to scientific research world wide.

    Friday, Oct. 3, 2014
    This column was written by Don Lincoln
    FNAL Don Lincoln
    Dr. Don Lincoln

    It’s hard for most people to imagine what it’s like at the heart of a particle collision. Two particles speed toward one another from opposite directions and their force fields intertwine, causing some of the particles’ constituents to be ejected. Or possibly the energy embodied in the interaction might be high enough to actually create matter and antimatter. It’s no wonder the whole process seems confusing.

    crash
    The same basic equations that govern the flow of water are important for describing the collisions of lead nuclei. In today’s article, we’ll get a glimpse of how this works.

    Things get a little easier to imagine when the particles are the nuclei of atoms (note that I said easier, not easy). For collisions between two nuclei of lead, one can imagine two small spheres, each containing 208 protons and neutrons, coming together to collide. Depending on the violence of the collision, some or many of the protons and neutrons might figuratively melt, releasing their constituent quarks so they can scurry around willy-nilly. Physicists call this form of matter a quark-gluon plasma, and it acts much like a liquid.

    pro
    The quark structure of the proton. The color assignment of individual quarks is arbitrary, but all three colors must be present. Forces between quarks are mediated by gluons

    neut
    The quark structure of the neutron. The color assignment of individual quarks is arbitrary, but all three colors must be present. Forces between quarks are mediated by gluons

    Part of this liquid-like behavior is due to the fact that so many particles are involved. An LHC collision between two lead nuclei might involve thousands or tens of thousands of particles. Because these particles are quarks and gluons, they experience the strong nuclear force. So as long as they are close enough to each other, the particles interact strongly enough that they clump a bit together. The net outcome is that the flow of particles from collision between lead nuclei looks vaguely like splashes of water. In these cases, the equations of hydrodynamics apply. Mathematical descriptions like these have been used to make sense of other features we see in LHC collisions between lead nuclei.

    glu
    In Feynman diagrams, emitted gluons are represented as helices. This diagram depicts the annihilation of an electron and positron.

    However, there is more to understand. We can imagine collisions between the collective 416 protons and neutrons of lead nuclei as splashes of water, but when a pair of protons collide, the collision doesn’t yield enough particles to exhibit hydrodynamic behavior. So as the number of particles involved goes down, the “splash” behavior must slowly go away. In addition, in the first studies of lead nuclei collisions, only the grossest features of the collision were studied. This is because it is impossible to identify individual quarks and gluons.

    There are ways to dig into these sorts of questions. One way is to look at collisions in which one beam is a proton and the other is a lead nucleus. This is a halfway point between the usual LHC proton-proton collisions and the lead-lead ones. In addition, we can turn our attention to quarks that we can unambiguously identify, such as bottom, charm and strange quarks, to better understand the hydrodynamic behavior.

    In this study, physicists looked at particles containing strange quarks. Since strange quarks don’t exist in the beam protons, studying them gives a unique window into the dynamics of lead-lead collisions. By combining studies of particles with strange quarks in lead-lead and lead-proton collisions, scientists hope to better understand the complicated and liquid-like behavior that is just beginning to reveal its secrets.

    See the full article here.

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  • richardmitnick 2:04 pm on October 2, 2014 Permalink | Reply
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    From Don Lincoln in Scientific American: “Particle Physics Informs the Ultimate Questions” 

    Scientific American

    Scientific American

    October 1, 2014
    Don Lincoln
    FNAL Don Lincoln
    Dr. Don Lincoln

    Editor’s Note: Author and Fermilab Senior Scientist Don Lincoln is set to teach “Mysteries of the Universe” from October 13 – 24 for Scientific American’s Professional Learning Program. We recently talked with Dr. Lincoln about why he became a physicist and his motivations to share what he discovers.

    When I was a young boy, I was insatiably curious. I must have driven my parents crazy with my incessant questions about why kittens had fur and why the moon was so much dimmer than the sun. I wanted to know the answer to everything. I still do.

    As I grew older, I began to see a pattern. While the answer to the kitten question might have started with biology and the answer to the moon question involved a combination of gravity, fusion and surface reflectivity, these weren’t the final answers. These interim answers led to new questions, which predictably led to atoms, then electrons and nuclei, to protons and neutrons. It became increasingly clear that what I really wanted to know was what [Albert] Einstein poetically called “God’s thoughts.” No matter your opinion on religion, the meaning of the phrase is clear: I wanted to know nothing less than the ultimate building blocks of the universe and the rules that bind them together. I wanted to know why the world was the way it was.

    As I matured intellectually, I came to realize that I wasn’t the first to ask these questions; indeed, they are among the oldest and grandest questions of all. For millennia, they were debated within the confines of philosophy and religion, but this began to change in the mid-1500s as the modern scientific method was being developed. Empirical testing replaced pure logic as the ultimate arbiter of ideas, leading to the approach still followed today.

    The Large Hadron Collider at the CERN laboratory is the world’s highest energy particle accelerator, a title that it is expected to hold for at least the next two decades. In this facility, scientists collide protons together at nearly the speed of light, generating temperatures at which the very idea of matter becomes hazy. Matter and energy convert back and forth, allowing physicists to gain new insights into the birth of the universe.

    CERN LHC Map
    CERN LHC Grand Tunnel
    CERN LHC particles
    LHC at CERN

    For those of us interested in the ultimate questions of the universe, there are really only two fields of interest: cosmology and particle physics. Cosmology deals with the universe as a whole: its birth, evolution and even its death. There is nothing small about cosmology. Particle physics, on the other hand, is concerned with the tiniest objects, the ultimate building blocks of the cosmos, usually studied by smashing two subatomic particles together at prodigious energies.

    These two realms—the grandness of the heavens for as far as we can see with our biggest telescopes and objects so unimaginably tiny that we needed to invent an entirely new form of physics to describe them—are intricately intertwined and the fact that we know this is one of the crowning triumphs of modern physics. Through centuries of effort, we now believe that the universe began about 14 billion years ago, in an awe-inspiring explosion that we call the Big Bang. At the moment of creation, the cosmos was much denser and hotter, with matter bathed in energies comparable to those achievable by modern particle accelerators.

    Using detectors weighing thousands of tons, particle physicists can record the behavior of matter at unprecedented energies and explore the environment last common at the very moment of creation. It was by studying collisions like the one shown here that scientists came to believe that they had discovered the Higgs boson.

    In essence, using a device like the Large Hadron Collider, we can create the conditions of the universe just fractions of a second after the Big Bang.

    While I’d love to know the answers to the ultimate questions of creation, these answers still elude us. So I elected to do the next best thing. I became a scientist and joined a multi-generational journey of discovery. It was through centuries of effort by curious men and women that we have come to our current understanding of the cosmos. In turn, my contemporaries and I are working to add to that long tradition, to write our own page in the book of knowledge, a book whose first pages were penned thousands of years ago. While it is unlikely any of us currently alive will see the final answer, for our brief time on Earth, we will follow the path laid out for us by the scientific greats of the past and point the way for those who come after. We must be satisfied by the wisdom that fulfillment is not about the destination, but in the way that we travel.

    Like many of my colleagues, I have joined the effort to use the Large Hadron Collider, located at the CERN laboratory in Europe, to better understand the behavior of matter under extreme conditions. The temperatures and pressures generated at the LHC haven’t been common since about a tenth of a trillionth of a second after the universe began. We’ve come a long way since our forebears stared at the stars under a clear and moonless sky and wondered. Being part of this community is how I’ve always wanted to live my life. As kids say nowadays, I am living the dream.

    However, for all of the successes of science, you should not think that we’ve understood everything. Far from it. There are many questions for which we don’t know the answer. For instance, we know that ordinary matter makes up only about 4 percent of the matter and energy in the universe. We don’t understand why our universe is made of matter, when we make matter and antimatter in equal quantities. While our current understanding would awe the best scientific minds of a century ago, there are certainly plenty of mysteries left for future generations. If you’re the sort who pestered your parents with questions about kittens and the moon, come join my colleagues and me. You’ll be among friends.

    Don Lincoln About the Author: Don Lincoln is a senior scientist at Fermi National Accelerator Laboratory.

    FNALTevatron
    Tevatron at Fermilab

    FNAL Wilson Hall
    Wilson Hall

    When he isn’t exploring the energy frontier, he is busy bringing that information to the public as the author of four books – including the newly released “The Large Hadron Collider: The Extraordinary Story of the Higgs Boson and Other Things That Will Blow Your Mind,” blogs for Nova and Johns Hopkins and numerous magazine articles, including two for Scientific American. He has created a series of You Tube videos and is teaching Mysteries of the Universe for the Professional Learning Program

    See the full article here.

    Scientific American, the oldest continuously published magazine in the U.S., has been bringing its readers unique insights about developments in science and technology for more than 160 years.

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