Higgs Boson

A boson particle which under Standard Model has 0 spin, a mass higher than 78 GeV and zero electric charge.

It hasn't been observed yet, just as the graviton hasn't been observed yet.

Scottish Physicsist, propsoed a method for spontaneous symmetry breaking of a system using a Higgs field (funny that), just the thing required to give every particle mass in the standard model, hence the Higgs' Boson.

Reecently retired, hoping someone will find his particle before he dies so that he can recieve a Nobel Prize. He smiled at me once, well, ok, he was smiling in the same corridor as me once, I am sure he didn't even notice me.

I have heard from those that know that he gave a very confusing course in quantum field theory.

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Just a comment on Smurfette's excellent writeup, in particle physics the way particles know what characteristics other particles have is by relaying intermidating particles between each other. Electrons tell each other about their charge by passing virtual photons amngst themselves, we say they are coupled together by photons. The intermediating particle for mass is thought to be the Higgs boson, however unlike with the electrons where the photon has no charge, the Higgs particle has a mass and so it couples to it'self. This leads to a bit of a mess in the calculations and to a rather large predicted mass for the Higgs particle, hence big accelerators are required.

The detection from CERN comes from a detector that is due to be closed down very shortly. They have said, "wait a moment look what we might have here, don't close us down" The detection seem to be marginal, makes you think eh! (not that I'm disputing them, just pointing out the importance in the timing of releasing scientific results)

European Scientists have obtained tantalising evidence of a subatomic particle called the Higgs. It is thought to give substance to all other matter in the Universe. The observation was made in the last month of an underground experiment that has been running since the late 1980's at the CERN laboratory near Geneva.

Discovering the Higgs particle has been one of the prime goals of physics in the past decade. Also known as the God particle , the Higgs particle holds a key place in the modern theory of matter.

First proposed in the 1960's by Edinburgh physicist Peter Higgs, the particle is imagined to give mass or weight to the other fundamental constituents of atoms. The particles are created by smashing atoms into each other at close to the speed of light. Vast detectors the size of warehouses pick up the debris from the collisions, and in the past 3 months CERN physicists have identified just 3 events in which something resembling the Higgs particle appeared.

The various elementary particles, both the matter (quarks and leptons) and force-carrying field particles (photons, gluons, gravitons, and the W and Z bosons) all have a wide range of masses. The photon and the gluon, for instance, have no mass at all, while the W and Z bosons carrying the weak nuclear force are the mass of a good-sized atomic nucleus. Why there should be such a large variation of masses is a major problem for the Standard Model of particle physics, and to solve the problem, Peter Higgs proposed that there should be a field that pervades the whole universe that particles interact with to acquire their masses: the strength of a particle's interaction with this field determines its mass. Like all quantum fields it should have a field boson associated with it, with spin zero as it is supposed to be a scalar field: the Higgs boson.

A useful analogy of this mechanism of the Higgs field giving particles their intrinsic masses would be to imagine a room full of members of a political party quietly chattering (space filled only with the Higgs field). An important politician (a massive particle) enters the room, creating a disturbance as he moves around, attracting clusters of admirers and petitioners alike. The commotion he creates produces resistance to his movement, in other words he acquires mass, just as a particle moving through the Higgs field would. Now imagine that a juicy rumor is whispered into the room. The rumor, as it spreads among the Party members, produces clusters as though someone important were there. These clusters are the Higgs bosons.

The Higgs boson is a vital component of Grand Unified Theories, that attempt to explain why the universe came into being the way it did, why the universe prefers to be filled with matter instead of antimatter, why there is something in the universe rather than nothing. Of course, this whole notion of "the God Particle" as it has been called, is just a theory, and there is, as of this writing, no direct experimental evidence for this field and the particle that is supposed to carry it. It is indeed possible, of course, as Dirac once noted (but speaking of magnetic monopoles) that "pretty mathematics by itself is not an adequate reason for nature to have made use of a theory." There might be other ways for nature to be choosing the masses of particles. However, current theoretical estimates (not from the Standard Model, which by itself cannot predict it, but from more ambitious theories such as supersymmetry and string theory) give the Higgs boson's own mass as somewhere between 60 GeV/c² (about the mass of an iron atom) and some 150 GeV/c² (roughly the mass of an atom of the rare earth metal samarium), meaning that only a very high energy event can allow us to observe one, if it does exist (it could even be as high as 1 TeV/c², but that's something that experimental physicists don't like to think about). The search for this particle is one of the main reasons why ever more powerful particle accelerators such as those at CERN and Fermilab are being built. Finding it would go a long way towards validating the correctness of the Standard Model.

Sources:

Arthur Beiser, Concepts of Modern Physics

The Waldegrave Higgs Challenge at http://hepwww.ph.qmw.ac.uk/epp/higgs.html

http://www.aip.org/enews/physnews/1996/split/pnu298-1.htm

http://lutece.fnal.gov/Drafts/Higgs.html

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The God Particle: If the Universe Is the Answer, What is the Question?
-Leon M. Lederman and Dick Teresi-

There are a few types of elementary particles (i.e. not composed of other particles) which show off different behaviours. They behave in accordance with their characteristics (being massive vs massless, electrically charged vs non-charged, non-interacting vs weakly-interacting or strongly-interacting and so on.) Physics explains the interplay between behaviours and the aforementioned features through the concept of fields. A field consists of a perturbation in a region of space caused by the presence of certain particles. When we deal with particles of matter, in which the most basic building blocks are the so-called fermions, the field makes them be compelled to motion.

For example, nearby meteorites are prone to fall towards the Earth because its fermions determine a gravitational field that influences other particles of matter. In the same way, charged particles generate an electromagnetic field that makes charged particles being repelled or attracted by other charged particles. So these fields explain the origin of some forces in nature, such as gravity and electromagnetism, and are known as force fields.

Motion's laws depicted by Newton link the behaviour of matter with its mass (for example, the bigger the mass, the bigger the gravity, and the further away from each other the masses are, the weaker the gravity between them.) The concept of mass is evidenced by the fact that every object resists attempts to change its motion state. This property (inertia) is ruled by a principle in which the bigger the mass, the greater the inertia. However, no explanation currently exists to answer why it should have mass in the first place.

There was no explanation for this until Peter W. Higgs, along with several other scientists, predicted in 1964 the existence of a new elementary particle, the Higgs boson. He suggested that a mass field, made up of his tiny bosons, might be spread through the universe, so that the particles of matter have been interacting with it since the big bang took place, 13.7 billion years ago, to keep them in their inertial state. In order to modify their motion, it is necessary to overcome the mass field influence.

Higgs postulated these bosons could only be found on their own at enormous temperatures, like those in the early post-big bang. Afterwards, the universe became cooler and they cannot be seen in nature any more, except perhaps in clusters, with no single boson sadly isolated.

In order to look for them, physicists have been trying to mimic the condition of high temperatures and high density that occurred for a short period after the big bang by means of bringing particles up to more than 99 per cent of light speed in accelerators such as the Large Hadron Collider at CERN. Once the obtained conditions replicate those in which bosons were capable of being in an isolated state it might be possible to discover them and study their properties. (1)

Recently physicists at CERN have achieved high-power collisions of elementary particles in their attempt to create mini-versions of the Big Bang, setting a record for the energy of particle conditions. They said the experiment was a major breakthrough because a point where nobody was before had been reached. (2)

In summary, scientists sifting debris from high-energy proton collisions at CERN have recorded hints of the Higgs boson existence. Perhaps soon they will have enough data to prove whether the hypothetical particle is a reality.

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Sources

1. http://www.exploratorium.edu/origins/cern/ideas/higgs.html

2. http://www.rte.ie/news/2010/0330/cern.html