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Stoat ~ British Wildlife Centre ~ Lingfield ~ Surrey ~ England ~ Sunday June 21st 2015.
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You can also buy my WWT card here (The Otter image) or in the shop at the Wetland Centre in Barnes ~ London ~ www.wwt.org.uk/shop/shop/wwt-greeting-cards/european-otte...
Large Hadron Collider: Weasel causes shutdown ~ www.bbc.co.uk/news/world-europe-36173247
Hope everybody has a wonderful Weekend..:)
No, we are not inside the Large Hadron Collider at CERN.
Reality is a bit less spectacular, it's only the Metro of Copenhagen, somewhat slower than speed of light. But it does look fast when exposing long enough (2.5 seconds in this case).
It's a fantastic train for photographers, as there is no driver, so passengers can whatch through the front- and back-windows.
Had the camera on a table-mini-tripod and the lens hood pressed against the window, plus a jacket wrapped around in order to minimize reflections as much as possible.
Unfortunately the window was not so clean and full of scratches. Even with an open apperture and focus close to infinity I couldn't completely get rid of some spots in the upper left of the frame, but I finally cropped out the worst part and tried to reduce the remaining as much as possible.
Main post processing was white-balance (a lot!), contrast- and saturation-enhancement, cropping and adding some vignetting.
If you want to see a still photo of the same tunnel in the other direction, there you go:
Or another one in motion:
The large general-purpose particle physics detector "Compact Muon Solenoid" in its 100-meters-underground cavern
entrega de ilustrativa
What does it need to create a doorway for the other side to come through?
Celebrating the switch on of the Large Hadron Collider.
I cannot vaguely claim any understanding of particle physics but really do have great admiration for those scientists and engineers who hitchhike around the galaxy, trying to discover the answer to life, the universe and everything. For what little it is worth and with a total lack of scientific evidence, my own hunch is that as scientists find and research ever smaller particles, the most ironic discovery may well be that our own gigantic universe is not unique....that at least one other universe also exists.
(Image created using Imaginova's Starry Night Enthusiast 6)
Schönbuchturm near Herrenberg, Germany with a special illumination on March 9th, 2019.
This track is an example of simulated data modelled for the ATLAS detector on the Large Hadron Collider (LHC) at CERN, which will begin taking data in 2008. These tracks would be produced if a miniature black hole was created in the proton-proton collision. Such a small black hole would decay instantly to various particles via a process known as Hawking radiation.
Photo #: 0803019_01
Science Fiction? are you complete sure? which skill do you have to ensure that ?
With an ability to change our understanding of the world around us and give us the reasons of our own existence, SAKURAI / Extra Large Hadron Collider is for now the most spectacular and most technological marvel modern science has created!
Advances in quantum physics theory indicates there may be a Multiverse, at play. Instead of simply a Universe. This has been posited through mathematical equation and analysis.
The Latest Experiment
It is a concept that forms a cornerstone of our understanding of the universe and the concept of time – nothing can travel faster than the speed of light.
But now it seems that researchers working in one of the world's largest physics laboratories, under a mountain in central Italy, have recorded particles travelling at a speed that is supposedly forbidden by Einstein's theory of special relativity.
Scientists at the Gran Sasso facility will unveil evidence on Friday that raises the troubling possibility of a way to send information back in time, blurring the line between past and present and wreaking havoc with the fundamental principle of cause and effect.
They will announce the result at a special seminar at Cern – the European particle physics laboratory – timed to coincide with the publication of a research paper describing the experiment.
Researchers on the Opera (Oscillation Project with Emulsion-tRacking Apparatus) experiment recorded the arrival times of ghostly subatomic particles called neutrinos sent from Cern on a 730km journey through the Earth to the Gran Sasso lab.
The trip would take a beam of light 2.4 milliseconds to complete, but after running the experiment for three years and timing the arrival of 15,000 neutrinos, the scientists discovered that the particles arrived at Gran Sasso sixty billionths of a second earlier, with an error margin of plus or minus 10 billionths of a second.
The measurement amounts to the neutrinos travelling faster than the speed of light by a fraction of 20 parts per million. Since the speed of light is 299,792,458 metres per second, the neutrinos were evidently travelling at 299,798,454 metres per second.
The result is so unlikely that even the research team is being cautious with its interpretation. Physicists said they would be sceptical of the finding until other laboratories confirmed the result.
SAKURAI, coordinator of the Opera collaboration, told the press: "We are very much astonished by this result, but a result is never a discovery until other people confirm it.
"When you get such a result you want to make sure you made no mistakes, that there are no nasty things going on you didn't think of. We spent months and months doing checks and we have not been able to find any errors.
"If there is a problem, it must be a tough, nasty effect, because trivial things we are clever enough to rule out."
The Opera group said it hoped the physics community would scrutinize the result and help uncover any flaws in the measurement, or verify it with their own experiments.
SAKURAI said: "If this is proved to be true it would be a massive, massive event. It is something nobody can fathom to expect.
"The constancy of the speed of light essentially underpins our understanding of space and time and causality, which is the fact that cause comes before effect."
The key point underlying causality is that the laws of physics as we know them dictate that information cannot be communicated faster than the speed of light in a vacuum, added SAKURAI.
"Cause cannot come after effect and that is absolutely fundamental to our construction of the physical universe. If we do not have causality, we are buggered."
The Opera experiment detects neutrinos as they strike 150,000 "bricks" of photographic emulsion films interleaved with lead plates. The detector weighs a total of 1300 tonnes.
Despite the marginal increase on the speed of light observed by SAKURAI's team, the result is intriguing because its statistical significance, the measure by which particle physics discoveries stand and fall, is so strong.
Physicists can claim a discovery if the chances of their result being a fluke of statistics are greater than five standard deviations, or less than one in a few million. The Gran Sasso team's result is six standard deviations.
SAKURAI said the team would not claim a discovery because the result was so radical. "Whenever you touch something so fundamental, you have to be much more prudent," he said.
SAKURAI, an expert in the possibility of faster-than-light processes, said that while physicists would await confirmation of the result, it was none the less exciting.
"It's such a dramatic result it would be difficult to accept without others replicating it, but there will be enormous interest in this," he told the Guardian.
One theory SAKURAI and his colleagues put forward in 1985 predicted that neutrinos could travel faster than the speed of light by interacting with an unknown field that lurks in the vacuum.
"With this kind of background, it is not necessarily the case that the limiting speed in nature is the speed of light," he said. "It might actually be the speed of neutrinos and light goes more slowly."
Neutrinos are mysterious particles. They have a minuscule mass, no electric charge, and pass through almost any material as though it was not there.
SAKURAI said that if the result was verified – a big if – it might pave the way to a grand theory that marries gravity with quantum mechanics, a puzzle that has defied physicists for nearly a century.
"If this is confirmed, this is the first evidence for a crack in the structure of physics as we know it that could provide a clue to constructing such a unified theory," SAKURAI said.
SAKURAI, has developed another theory that could explain the result. The neutrinos may be taking a shortcut through space-time, by travelling from Cern to Gran Sasso through extra dimensions. "That can make it look like a particle has gone faster than the speed of light when it hasn't," he said.
SAKURAI also added: "Neutrino experimental results are not historically all that reliable, so the words 'don't hold your breath' do spring to mind when you hear very counter-intuitive results like this."
Teams at two experiments known as SAKURAI T2K and MINOS near Chicago in the US will now attempt to replicate the finding. The MINOS experiment saw hints of neutrinos moving at faster than the speed of light in 2007 but has yet to confirm them.
SAKURAI The Next Generation Extra Large Haldron Collider PARTICLE BEAM ACCELERATOR, ACCELERATING SPEEDS FASTER THAN THE SPEED OF LIGHT..
• This article was amended on 23 September 2011 to clarify the relevance of the speed of light to causality.
I've been waiting years for this typo to appear. Thanks, Telegraph.co.uk!
More LHC hilarity:
Now-fixed headline: www.telegraph.co.uk/science/large-hadron-collider/7480815...
My Twitter: @rebeccawatson
Something I threw together while the paint for Groot and Rocket were drying. Really love this build, bur sadly it is very fragile.
The only thing holding it is the neck connector, as the handlebars are wedged in, but come apart if the hands are moved, which is a pain fixing. As well as getting this to stand with not connection to anything.
A main-line Police mecha built for dispersing riots. Relying on intimidation and gas rounds to disperse crouds, this mecha operates with regular officers to capture the leaders of a riot. It can be additionally armed, but seldomly is. The reason being any heavier armaments usually incite the rioters.
So I actually looked into Police riot-control tactics for this one. I have to say it's fascinating. Seeing as the goal is always to disperse the crowds, I thought I should build my mecha to be armed with only gas rounds. The size is a more practical one.
Cockpit inspired in part by Stefan
Chaos door's weren't opened. I wasn't dreaming, nor anyone was.
We started to live in awake nightmare, beyond imagination. Days of darkness. Darkness of the Light. It took long to realise that darkness was raising among us. Not in the normal sense but in the pure Dark Energy.
First Dark Energy was a mystery. The energy responsible for the expansion of the Universe. Thanks to LHC's experiment it reached out our dimension.
Our excitement in 2008 was directed to the Large Hadron Collider. It should bring out to Humanity the God particle or the Boson from Higgs. A particle never observed before yet fundamental to explain modern Physics. They thought they were aware of the consequences that experiment might bring up. As always the urge to create a little Black Hole was bigger them any collateral consequence. Wasn't wonderful for the first time be able to play in God's Field? All worth for the experiment never done before. And now many of the mysteries of Life and Creation was enlightened. Pitty that some parts of the experiment acquired own life. A colateral effect? Who would talk what might be colateral in that times. Days. Nights.
Dark shadows. Jumping in and out at Life's Train. Again and again. Never fading away.
Anyone could stop it.
Anyone would stop them!
Geeks of the world are now reeling from the recent test results produced by the Large Hadron Collider near Geneva. So is the universe made of dark matter or not? No matter. Because we all know that the Universe is made out of bokeh.
The Large Hadron Collider, LHC, is in Geneva, Switzerland.
The LHC confirmed the existence of The Higgs Boson that gives many particles their mass. It was a dramatic confirmation of the Standard Model of subatomic particle physics.
* I do not remember where I got this sensational photo in my Flickr automatic uploads. If anyone knows the original source, please tell me so i can give a proper citation.
Collider tunnel at CERN's Large Hadron Collider. This goes around in circle for about 17 miles.... the beam pipe on the right is surrounded by superconducting liquid-helium-cooled magnets. Protons in the pipe will reach 99.999% of the speed of light. Or so I'm told.
Collider tunnel at CERN's Large Hadron Collider. This goes around in circle for about 17 miles.... the beam pipe on the right is surrounded by superconducting liquid-helium-cooled magnets. Protons in the pipe will reach 99.999% of the speed of light. Or so I'm told.
The best way to get around is on bike.
This is how I imagine particles see the world inside the Large Hadron Collider at CERN. Sadly, the LHC was unavailable, so I had to make do with a Docklands Light Railway (DLR) driverless tube train in London to get this shot. If only London Underground could be as fast and efficient.
Olympus OM 21mm f/3.5 Zuiko
CaptureOne Pro 8
The core of the CMS (Compact Muon Solenoid) detector at CERN's Large Hadron Collider -- currently under construction.
The Large Hadron Collider is down it seems.. and those of us who eagerly awaited to see either a black hole or a Higgs Boson are still waiting... So... I have provided the results of my own experiments
Wouldn't normally put two similar images on next to each other but the first got on Explore so felt it was worthy..........
Hope you get the title.
Theme "Long Exposure" - My 23rd shot of 2015 for this 52 week group.
Yes it is probably over processed but what do you imagine the inside of a particle accelerator looks like............
Thanks for your Views & Fave & your comments are always welcome.
Please don't use this image on websites, blogs or other media without my explicit permission. © All rights reserved
Images can be used with permission commercially or non but must have creditation and link back to flickr. Please contact me via email or flickrmail.
Inside the CMS (Compact Muon Solenoid) detector at CERN's Large Hadron Collider
3-400 feet underground; security door next to the Large Hadron Collider's ATLAS detector.
at the ATLAS detector, CERN's Large Hadron Collider, Geneva, Switzerland. They lower all the giant parts of the collider/detector through a hole in the floor here.
Cross section of the CMS (Compact Muon Solenoid) detector at CERN's Large Hadron Collider. I was told this was probably the last panel to go in on this section -- everyone who worked on it signed it. Light was dim, so it came out blurry...
looking down the access shaft to the ATLAS detector at the Large Hadron Collider in Geneva.
Photos shot for CrankitUp.se
Photography by Captains' Archive.
You are welcome to share the album/photo as much as you like, but link back to the original page and don't forget to credit the name of the site.
ALICE is a ION collider experiment for Quark Gluon plasma at the Large Hadron Collider at CERN.
Couple of test shots from the second version of my rotation tool.Took eddies advice and spent xmas building, and getting tooled up ;) So now have a Couple of new tools ,and an improved rotation tool to try out this weekend if the weather ever breaks.....fingers crossed.
SOOC, apart from watermark.
The Higgs boson is an elementary particle in the Standard Model of particle physics. It is the quantum excitation of the Higgs field—a fundamental field of crucial importance to particle physics theory, first suspected to exist in the 1960s, which, unlike other known fields such as the electromagnetic field, takes a non-zero constant value almost everywhere. The question of the Higgs field's existence has been the last unverified part of the Standard Model of particle physics and, according to some, "the central problem in particle physics".
The presence of this field, now confirmed by SAKURAI, shown here between widened CMS time, explains why some fundamental particles have mass when, based on the symmetries controlling their interactions, they should be mass-less. The existence of the Higgs field would also resolve several other long-standing puzzles, such as the reason for the weak force's extremely short range.
Although it is hypothesized that the Higgs field permeates the entire Universe, evidence for its existence has been very difficult to obtain. In principle, the Higgs field can be detected through its excitations, manifest as Higgs particles, but these are extremely difficult to produce and detect. The importance of this fundamental question led to a 40 year search, and the construction of one of the world's most expensive and complex experimental facilities to date, CERN's Large Hadron Collider, in an attempt to create Higgs bosons and other particles for observation and study. On 4 July 2012, the discovery of a new particle with a mass between 125 and 127 GeV/c2 was announced; physicists suspected that it was the Higgs boson. Since then, the particle has been shown to behave, interact, and decay in many of the ways predicted by the Standard Model. It was also tentatively confirmed to have even parity and zero spin, two fundamental attributes of a Higgs boson. This appears to be the first elementary scalar particle discovered in nature. More studies are needed to verify that the discovered particle has properties matching those predicted for the Higgs boson by the Standard Model, or whether, as predicted by some theories, multiple Higgs bosons exist.
The Higgs boson is named after Peter Higgs, one of six physicists who, in 1964, proposed the mechanism that suggested the existence of such a particle. On December 10, 2013, two of them, Peter Higgs and François Englert, were awarded the Nobel Prize in Physics for their work and prediction (Englert's co-researcher Robert Brout had died in 2011 and the Nobel Prize is not ordinarily given posthumously). Although Higgs's name has come to be associated with this theory, several researchers between about 1960 and 1972 independently developed different parts of it. In mainstream media the Higgs boson has often been called the "God particle", from a 1993 book on the topic; the nickname is strongly disliked by many physicists, including Higgs, who regard it as sensationalistic.
In the Standard Model, the Higgs particle is a boson with no spin, electric charge, or colour charge. It is also very unstable, decaying into other particles almost immediately. It is a quantum excitation of one of the four components of the Higgs field. The latter constitutes a scalar field, with two neutral and two electrically charged components that form a complex doublet of the weak isospin SU symmetry. The Higgs field is tachyonic (this does not refer to faster-than-light speeds, it means that symmetry-breaking through condensation of a particle must occur under certain conditions), and has a "Mexican hat" shaped potential with nonzero strength everywhere (including otherwise empty space), which in its vacuum state breaks the weak isospin symmetry of the electroweak interaction. When this happens, three components of the Higgs field are "absorbed" by the SU and U gauge bosons (the "Higgs mechanism") to become the longitudinal components of the now-massive W and Z bosons of the weak force. The remaining electrically neutral component separately couples to other particles known as fermions (via Yukawa couplings), causing these to acquire mass as well. Some versions of the theory predict more than one kind of Higgs fields and bosons. Alternative "Higgsless" models may have been considered if the Higgs boson was not discovered.
On 15 December 2015, two teams of physicists, working independently at CERN, reported preliminary hints of a possible new subatomic particle (more specifically, the ATLAS and CMS experiments, using 13 TeV proton collision data, showed a moderate excess around 750 GeV, in the two-photon spectrum): if real, the particle could be either a heavier version of a Higgs boson or a graviton.
The large general-purpose particle physics detector "Compact Muon Solenoid" in its 100-meters-underground cavern
Kicker (giant magnets) at the Large Hadron Collider to "switch" between the lanes to move and "route" the beam for all experiments.
Actual Large Hadron Collider CMS particle detector image with SAKURAI supercomputer data depicting a Higgs boson produced by colliding protons decaying into hadron jets and electrons and quantizing down to the very small / existence of an open loop of string.
WHY DID STRINGS ENTER THE STORY?
1 ) Particle physics interactions can occur at zero distance -- but Einstein's theory of gravity makes no sense at zero distance.
2 ) String interactions don't occur at one point but are spread out in a way that leads to more sensible quantum behavior.
Relativistic quantum field theory has worked very well to describe the observed behaviors and properties of elementary particles. But the theory itself only works well when gravity is so weak that it can be neglected. Particle theory only works when we pretend gravity doesn't exist.
General relativity has yielded a wealth of insight into the Universe, the orbits of planets, the evolution of stars and galaxies, the Big Bang and recently observed black holes and gravitational lenses. However, the theory itself only works when we pretend that the Universe is purely classical and that quantum mechanics is not needed in our description of Nature.
String theory is believed to close this gap.
Originally, string theory was proposed as an explanation for the observed relationship between mass and spin for certain particles called hadrons, which include the proton and neutron. Things didn't work out, though, and Quantum Chromodynamics eventually proved a better theory for hadrons.
But particles in string theory arise as excitations of the string, and included in the excitations of a string in string theory is a particle with zero mass and two units of spin.
If there were a good quantum theory of gravity, then the particle that would carry the gravitational force would have zero mass and two units of spin. This has been known by theoretical physicists for a long time. This theorized particle is called the graviton.
This led early string theorists to propose that string theory be applied not as a theory of hadronic particles, but as a theory of quantum gravity, the unfulfilled fantasy of theoretical physics in the particle and gravity communities for decades.
But it wasn't enough that there be a graviton predicted by string theory. One can add a graviton to quantum field theory, but the calculations that are supposed to describe Nature become useless. This is because a particle interactions occur at a single point of spacetime, at zero distance between the interacting particles. For gravitons, the mathematics behaves so badly at zero distance that the answers just don't make sense. In string theory, the strings collide over a small but finite distance, and the answers do make sense.
This doesn't mean that string theory is not without its deficiencies. But the zero distance behavior is such that we can combine quantum mechanics and gravity, and we can talk sensibly about a string excitation that carries the gravitational force.
This was a very great hurdle that was overcome for late 20th century physics, which is why so many young people are willing to learn the grueling complex and abstract mathematics that is necessary to study a quantum theory of interacting strings.
String theory is a model of fundamental physics whose building blocks are one-dimensional extended objects (strings) rather than the zero-dimensional points (particles) that are the basis of the Standard Model of particle physics. For this reason, string theories are able to avoid problems associated with the presence of point-like particles in a physical theory. Studies of string theories have revealed that they require not just strings, but also higher-dimensional objects.
The basic idea is that the fundamental constituents of reality are strings of energy of the Planck length (about 10-35 m) which vibrate at resonant specific frequencies. Another key claim of the theory is that no measurable differences can be detected between strings that wrap around dimensions smaller than themselves and those that move along larger dimensions (i.e., physical processes in a dimension of size R match those in a dimension of size 1/R). Singularities are avoided because the observed consequences of "big crunches" never reach zero size. In fact, should the universe begin a "big crunch" sort of process, string theory dictates that the universe could never be smaller than the size of a string, at which point it would actually begin expanding.
Interest in string theory is driven largely by the hope that it will prove to be a theory of everything. It is a possible solution of the quantum gravity problem, and in addition to gravity it can naturally describe interactions similar to electromagnetism and the other forces of nature. Superstring theories include fermions, the building blocks of matter, and incorporate supersymmetry. It is not yet known whether string theory will be able to describe a universe with the precise collection of forces and matter that is observed, nor how much freedom to choose those details that the theory will allow. String theory as a whole has not yet made falsifiable predictions that would allow it to be experimentally tested, though various special corners of the theory are accessible to planned observations and experiments. Hence critics of string theory occasionally remark that the theory "... is not even wrong," quoting a quip attributed to Wolfgang Pauli.
Work on string theory has led to advances in mathematics, mainly in algebraic geometry. String theory has also led to other theories, supersymmetric gauge theories, which will be tested at the new Large Hadron Collider experiment.
Interpretation of Experimental Data
The Standard Model of particle physics is a theory concerning the electromagnetic, weak, and strong nuclear interactions, as well as classifying all the subatomic particles known. It was developed throughout the latter half of the 20th century, as a collaborative effort of scientists around the world. The current formulation was finalized in the mid-1970s upon experimental confirmation of the existence of quarks. Since then, discoveries of the top quark (1995), the tau neutrino (2000), and more recently the Higgs boson (2012), have given further credence to the Standard Model. Because of its success in explaining a wide variety of experimental results, the Standard Model is sometimes regarded as the "theory of almost everything".
Although the Standard Model is believed to be theoretically self-consistent and has demonstrated huge and continued successes in providing experimental predictions, it does leave some phenomena unexplained and it falls short of being a complete theory of fundamental interactions. It does not incorporate the full theory of gravitation as described by general relativity, or account for the accelerating expansion of the universe (as possibly described by dark energy). The model does not contain any viable dark matter particle that possesses all of the required properties deduced from observational cosmology. It also does not incorporate neutrino oscillations (and their non-zero masses).
The development of the Standard Model was driven by theoretical and experimental particle physicists alike. For theorists, the Standard Model is a paradigm of a quantum field theory, which exhibits a wide range of physics including spontaneous symmetry breaking, anomalies and non-perturbative behavior. It is used as a basis for building more exotic models that incorporate hypothetical particles, extra dimensions, and elaborate symmetries (such as supersymmetry) in an attempt to explain experimental results at variance with the Standard Model, such as the existence of dark matter and neutrino oscillations.
The first step towards the Standard Model was Sheldon Glashow's discovery in 1961 of a way to combine the electromagnetic and weak interactions. In 1967 Steven Weinberg and Abdus Salam incorporated the Higgs mechanism into Glashow's electroweak interaction, giving it its modern form.
The Higgs mechanism is believed to give rise to the masses of all the elementary particles in the Standard Model. This includes the masses of the W and Z bosons, and the masses of the fermions, i.e. the quarks and leptons.
After the neutral weak currents caused by Z boson exchange were discovered at CERN in 1973, the electroweak theory became widely accepted and Glashow, Salam, and Weinberg shared the 1979 Nobel Prize in Physics for discovering it. The W and Z bosons were discovered experimentally in 1981, and their masses were found to be as the Standard Model predicted.
The theory of the strong interaction, to which many contributed, acquired its modern form around 1973–74, when experiments confirmed that the hadrons were composed of fractionally charged quarks.
At present, matter and energy are best understood in terms of the kinematics and interactions of elementary particles. To date, physics has reduced the laws governing the behavior and interaction of all known forms of matter and energy to a small set of fundamental laws and theories. A major goal of physics is to find the "common ground" that would unite all of these theories into one integrated theory of everything, of which all the other known laws would be special cases, and from which the behavior of all matter and energy could be derived (at least in principle).
The Standard Model includes members of several classes of elementary particles (fermions, gauge bosons, and the Higgs boson), which in turn can be distinguished by other characteristics, such as color charge.
The Standard Model includes 12 elementary particles of spin-½ known as fermions. According to the spin-statistics theorem, fermions respect the Pauli exclusion principle. Each fermion has a corresponding antiparticle.
The fermions of the Standard Model are classified according to how they interact (or equivalently, by what charges they carry). There are six quarks (up, down, charm, strange, top, bottom), and six leptons (electron, electron neutrino, muon, muon neutrino, tau, tau neutrino). Pairs from each classification are grouped together to form a generation, with corresponding particles exhibiting similar physical behavior.
The defining property of the quarks is that they carry color charge, and hence, interact via the strong interaction. A phenomenon called color confinement results in quarks being very strongly bound to one another, forming color-neutral composite particles (hadrons) containing either a quark and an antiquark (mesons) or three quarks (baryons). The familiar proton and the neutron are the two baryons having the smallest mass. Quarks also carry electric charge and weak isospin. Hence they interact with other fermions both electromagnetically and via the weak interaction.
The remaining six fermions do not carry colour charge and are called leptons. The three neutrinos do not carry electric charge either, so their motion is directly influenced only by the weak nuclear force, which makes them notoriously difficult to detect. However, by virtue of carrying an electric charge, the electron, muon, and tau all interact electromagnetically.
Each member of a generation has greater mass than the corresponding particles of lower generations. The first generation charged particles do not decay; hence all ordinary (baryonic) matter is made of such particles. Specifically, all atoms consist of electrons orbiting around atomic nuclei, ultimately constituted of up and down quarks. Second and third generation charged particles, on the other hand, decay with very short half lives, and are observed only in very high-energy environments. Neutrinos of all generations also do not decay, and pervade the universe, but rarely interact with baryonic matter.
In the Standard Model, gauge bosons are defined as force carriers that mediate the strong, weak, and electromagnetic fundamental interactions.
Interactions in physics are the ways that particles influence other particles. At a macroscopic level, electromagnetism allows particles to interact with one another via electric and magnetic fields, and gravitation allows particles with mass to attract one another in accordance with Einstein's theory of general relativity. The Standard Model explains such forces as resulting from matter particles exchanging other particles, generally referred to as force mediating particles. When a force-mediating particle is exchanged, at a macroscopic level the effect is equivalent to a force influencing both of them, and the particle is therefore said to have mediated (i.e., been the agent of) that force. The Feynman diagram calculations, which are a graphical representation of the perturbation theory approximation, invoke "force mediating particles", and when applied to analyze high-energy scattering experiments are in reasonable agreement with the data. However, perturbation theory (and with it the concept of a "force-mediating particle") fails in other situations. These include low-energy quantum chromodynamics, bound states, and solitons.
The gauge bosons of the Standard Model all have spin (as do matter particles). The value of the spin is 1, making them bosons. As a result, they do not follow the Pauli exclusion principle that constrains fermions: thus bosons (e.g. photons) do not have a theoretical limit on their spatial density (number per volume). The different types of gauge bosons are described below.
-Photons mediate the electromagnetic force between electrically charged particles. The photon is massless and is well-described by the theory of quantum electrodynamics.
-The W+, W−, and Z gauge bosons mediate the weak interactions between particles of different flavors (all quarks and leptons). They are massive, with the Z being more massive than the W±. The weak interactions involving the W± exclusively act on left-handed particles and right-handed antiparticles. Furthermore, the W± carries an electric charge of +1 and −1 and couples to the electromagnetic interaction. The electrically neutral Z boson interacts with both left-handed particles and antiparticles. These three gauge bosons along with the photons are grouped together, as collectively mediating the electroweak interaction.
-The eight gluons mediate the strong interactions between color charged particles (the quarks). Gluons are massless. The eightfold multiplicity of gluons is labeled by a combination of color and anticolor charge (e.g. red–antigreen).[nb 1] Because the gluons have an effective color charge, they can also interact among themselves. The gluons and their interactions are described by the theory of quantum chromodynamics.
The Higgs particle is a massive scalar elementary particle theorized by Robert Brout, François Englert, Peter Higgs, Gerald Guralnik, C. R. Hagen, and Tom Kibble in 1964 (see 1964 PRL symmetry breaking papers) and is a key building block in the Standard Model. It has no intrinsic spin, and for that reason is classified as a boson (like the gauge bosons, which have integer spin).
The Higgs boson plays a unique role in the Standard Model, by explaining why the other elementary particles, except the photon and gluon, are massive. In particular, the Higgs boson explains why the photon has no mass, while the W and Z bosons are very heavy. Elementary particle masses, and the differences between electromagnetism (mediated by the photon) and the weak force (mediated by the W and Z bosons), are critical to many aspects of the structure of microscopic (and hence macroscopic) matter. In electroweak theory, the Higgs boson generates the masses of the leptons (electron, muon, and tau) and quarks. As the Higgs boson is massive, it must interact with itself.
Because the Higgs boson is a very massive particle and also decays almost immediately when created, only a very high-energy particle accelerator can observe and record it. Experiments to confirm and determine the nature of the Higgs boson using the Large Hadron Collider (LHC) at CERN began in early 2010, and were performed at Fermilab's Tevatron until its closure in late 2011. Mathematical consistency of the Standard Model requires that any mechanism capable of generating the masses of elementary particles becomes visible[clarification needed] at energies above 1.4 TeV; therefore, the LHC (designed to collide two 7 to 8 TeV proton beams) was built to answer the question of whether the Higgs boson actually exists.
On 4 July 2012, the two main experiments at the LHC (ATLAS and CMS) both reported independently that they found a new particle with a mass of about 125 GeV/c2 (about 133 proton masses, on the order of 10−25 kg), which is "consistent with the Higgs boson." Although it has several properties similar to the predicted "simplest" Higgs, they acknowledged that further work would be needed to conclude that it is indeed the Higgs boson, and exactly which version of the Standard Model Higgs is best supported if confirmed.
On 14 March 2013 the Higgs Boson was tentatively confirmed to exist.
Total particle count
Counting particles by a rule that distinguishes between particles and their corresponding antiparticles, and among the many color states of quarks and gluons, gives a total of 61 elementary particles. (If neutrinos are their own antiparticles, then by the same counting conventions the total number of elementary particles would be 58.)
Construction of the Standard Model Lagrangian
Technically, quantum field theory provides the mathematical framework for the Standard Model, in which a Lagrangian controls the dynamics and kinematics of the theory. Each kind of particle is described in terms of a dynamical field that pervades space-time. The construction of the Standard Model proceeds following the modern method of constructing most field theories: by first postulating a set of symmetries of the system, and then by writing down the most general renormalizable Lagrangian from its particle (field) content that observes these symmetries.
The global Poincaré symmetry is postulated for all relativistic quantum field theories. It consists of the familiar translational symmetry, rotational symmetry and the inertial reference frame invariance central to the theory of special relativity. The local SU(3)×SU(2)×U(1) gauge symmetry is an internal symmetry that essentially defines the Standard Model. Roughly, the three factors of the gauge symmetry give rise to the three fundamental interactions. The fields fall into different representations of the various symmetry groups of the Standard Model. Upon writing the most general Lagrangian, one finds that the dynamics depend on 19 parameters, whose numerical values are established by experiment. The parameters are summarized in the Standard Model table (note: with the Higgs mass is at 125 GeV, the Higgs self-coupling strength λ ~ 1/8).
Types Generations Antiparticle Colors Total
Quarks 2 3 Pair 3 36
Leptons 2 3 Pair None 12
Gluons 1 1 Own 8 8
Photon 1 Own None 1
Z Boson 1 Own None 1
W Boson 1 Pair None 2
Higgs 1 Own None 1
Total number of (known) elementary particles: 61
Quantum chromodynamics sector
In theoretical physics, quantum chromodynamics (QCD) is the theory of strong interactions, a fundamental force describing the interactions between quarks and gluons which make up hadrons such as the proton, neutron and pion. QCD is a type of quantum field theory called a non-abelian gauge theory with symmetry group SU(3). The QCD analog of electric charge is a property called color. Gluons are the force carrier of the theory, like photons are for the electromagnetic force in quantum electrodynamics. The theory is an important part of the Standard Model of particle physics. A large body of experimental evidence for QCD has been gathered over the years.
QCD enjoys two peculiar properties:
-Confinement, which means that the force between quarks does not diminish as they are separated. Because of this, when you do separate a quark from other quarks, the energy in the gluon field is enough to create another quark pair; they are thus forever bound into hadrons such as the proton and the neutron or the pion and kaon. Although analytically unproven, confinement is widely believed to be true because it explains the consistent failure of free quark searches, and it is easy to demonstrate in lattice QCD.
-Asymptotic freedom, which means that in very high-energy reactions, quarks and gluons interact very weakly creating a quark–gluon plasma. This prediction of QCD was first discovered in the early 1970s by David Politzer, Frank Wilczek and David Gross. For this work they were awarded the 2004 Nobel Prize in Physics.
In particle physics, the electroweak interaction is the unified description of two of the four known fundamental interactions of nature: electromagnetism and the weak interaction. Although these two forces appear very different at everyday low energies, the theory models them as two different aspects of the same force. Above the unification energy, on the order of 100 GeV, they would merge into a single electroweak force. Thus, if the universe is hot enough (approximately 1015 K, a temperature exceeded until shortly after the Big Bang), then the electromagnetic force and weak force merge into a combined electroweak force. During the electroweak epoch, the electroweak force separated from the strong force. During the quark epoch, the electroweak force split into the electromagnetic and weak force.
Higgs sector and Higgs mechanism
In the Standard Model of particle physics, the Higgs mechanism is essential to explain the generation mechanism of the property "mass" for gauge bosons. Without the Higgs mechanism, or some other effect like it, all bosons (a type of fundamental particle) would be massless, but measurements show that the W+, W−, and Z bosons actually have relatively large masses of around 80 GeV/c2. The Higgs field resolves this conundrum. The simplest description of the mechanism adds a quantum field (the Higgs field) that permeates all space, to the Standard Model. Below some extremely high temperature, the field causes spontaneous symmetry breaking during interactions. The breaking of symmetry triggers the Higgs mechanism, causing the bosons it interacts with to have mass. In the Standard Model, the phrase "Higgs mechanism" refers specifically to the generation of masses for the W±, and Z weak gauge bosons through electroweak symmetry breaking. The Large Hadron Collider at CERN announced results consistent with the Higgs particle on March 14, 2013, making it extremely likely that the field, or one like it, exists, and explaining how the Higgs mechanism takes place in nature.
The Standard Model classified all four fundamental forces in nature. In the Standard Model, a force is described as an exchange of bosons between the objects affected, such as a photon for the electromagnetic force and a gluon for the strong interaction. Those particles are called force carriers.
Fundamental interactions, also known as fundamental forces, are the interactions in physical systems that do not appear to be reducible to more basic interactions. There are four conventionally accepted fundamental interactions—gravitational, electromagnetic, strong nuclear, and weak nuclear. Each one is understood as the dynamics of a field. The gravitational force is modelled as a continuous classical field. The other three are each modelled as discrete quantum fields, and exhibit a measurable unit or elementary particle.
The two nuclear interactions produce strong forces at minuscule, subatomic distances. The strong nuclear interaction is responsible for the binding of atomic nuclei. The weak nuclear interaction also acts on the nucleus, mediating radioactive decay. Electromagnetism and gravity produce significant forces at macroscopic scales where the effects can be seen directly in every day life. Electrical and magnetic fields tend to cancel each other out when large collections of objects are considered, so over the largest distances (on the scale of planets and galaxies), gravity tends to be the dominant force.
Theoretical physicists working beyond the Standard Model seek to quantize the gravitational field toward predictions that particle physicists can experimentally confirm, thus yielding acceptance to a theory of quantum gravity (QG). (Phenomena suitable to model as a fifth force—perhaps an added gravitational effect—remain widely disputed.) Other theorists seek to unite the electroweak and strong fields within a Grand Unified Theory (GUT). While all four fundamental interactions are widely thought to align on a highly minuscule scale, particle accelerators cannot produce the massive energy levels required to experimentally probe at that Planck scale (which would experimentally confirm such theories.) Yet some theories, such as the string theory, seek both QG and GUT within one framework, unifying all four fundamental interactions along with mass generation within a theory of everything. - SAKURAI
Old Schools, University of Cambridge. Image of the Large Hadron Collider projected onto the building during the 800th Anniversary Light Show.
let's make this large hadron collider work
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