Taking a closer look at LHC

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STANDARD MODEL

The Standard Model of Particle Physics is the best theory that physicists currently have to describe the building blocks of the universe. It is one of the biggest scientific achievements in twentieth-century science.

The Standard Model describes the universe using 6 quarks, 6 leptons and a few force-carrying particles. There are four known forces (or interactions), each mediated by a fundamental particle, known as a carrier particle. Photons, gravitons, and gluons have no mass, whereas weak-force carrier particles have mass 80-90 GeV. Gravity is only included in the Standard Model by tentative hypothesis, but gravitons have never been directly observed.

At very high energies levels and very small scales the other three forces become almost identical, but the convergence is imperfect. Electromagnetic & gravitational forces vary as the inverse square of distance without limit (to infinity).

But the strong and weak nuclear forces are short-range rather than inverse-square forces. Short-range forces only operate at very short ranges through the exchange of particles. Whereas inverse-square forces have no range-limits. It is the non-zero rest mass of the short-range force-mediating particles which causes them to decay quickly and thereby limits their range. For the strong nuclear force the exchange-particle is the gluon (nuclear "glue"). For the weak nuclear force the exchange-particle is W+, W- or Z.

Particles that are affected by the strong nuclear force are called hadrons, whereas leptons are not affected. Hadrons are formed by quarks, so they are not considered elementals, but leptons have no structure and they are thus truly elementary.

There are six types (also so-called flavors) for quarks and leptons.

Leptons can exist being isolated but quarks are always associated in three (baryons) or in pairs quark and antiquark (mesons). Protons and neutrons are the most known baryons and pions and kaons are the most known mesons.

Quarks only exist inside hadrons because they are confined by the strong force fields. Therefore, we cannot measure their mass by isolating them. The nature of the strong force between quarks does not permit isolated individual quarks to exist.
This is a radically new feature of the strong force, never before encountered, but understandable in terms of the details of the strong forces characteristics.

All particles are classed as either fermions or bosons . The difference among them is due to their spin

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Fermion: name for a particle that is a matter constituent, characterized by spin in odd half integer quantum units (1/2,3/2,5/2...). Named for Italian physicist Enrico Fermi. Quarks, leptons and baryons are all fermions.

Fermions, cannot occupy the same quantum state as each other. They obey the Fermi-Dirac statistics and the Pauli exclusion principle. They "resist" being placed close to each other. So, fermions possess "rigidness" and thus sometimes are considered to be "particles of matter".

The Pauli exclusion principle obeyed by fermions is responsible for the stability of the electron shells of atoms (thus for stability of atomic matter). It also is responsible for the complexity of atoms (making it impossible for all atomic electrons to occupy the same energy level), thus making complex chemistry possible. It is also responsible for the pressure within degenerate matter which largely governs the equilibrium state of white dwarfs and neutron stars.
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Boson: name for any particle with a spin of an integer number ( 0,1 or 2...) of quantum units of angular momentum. (named for Indian physicist S.N. Bose). The carrier particles of all interactions are bosons. Mesons are also bosons.

In contrast to fermions, several bosons can occupy the same quantum state. Thus, bosons with the same energy can occupy the same place in space. The only two bosons in the Standard Model that are yet to be discovered experimentally are the Higgs boson and the graviton.
The properties of lasers and masers, superfluid helium-4 and Bose–Einstein condensates are all consequences of statistics of bosons.

The Standard Model of Particle Physics is the best theory that physicists currently have to describe the building blocks of the universe. It is one of the biggest scientific achievements in twentieth-century science.
The Standard Model describes the universe using 6 quarks, 6 leptons and a few force-carrying particles. There are four known forces (or interactions), each mediated by a fundamental particle, known as a carrier particle. Photons, gravitons, and gluons have no mass, whereas weak-force carrier particles have mass 80-90 GeV. Gravity is only included in the Standard Model by tentative hypothesis, but gravitons have never been directly observed.

	STANDARD MODEL
	ANTIMATTER
	INTERACTIONS
	FEYNMAN DIAGRAMS
	HIGGS PARTICLE
	VIOLATION CP
	SUPERSYMMETRY
	AND BEYOND


At very high energies levels and very small scales the other three forces become almost identical, but the convergence is imperfect. Electromagnetic & gravitational forces vary as the inverse square of distance without limit (to infinity). But the strong and weak nuclear forces are short-range rather than inverse-square forces. Short-range forces only operate at very short ranges through the exchange of particles. Whereas inverse-square forces have no range-limits. It is the non-zero rest mass of the short-range force-mediating particles which causes them to decay quickly and thereby limits their range. For the *strong* *nuclear force* the exchange-particle is the gluon (nuclear "glue"). For the weak nuclear force the exchange-particle is W+, W- or Z.
Particles that are affected by the strong nuclear force are called hadrons, whereas leptons are not affected. Hadrons are formed by quarks, so they are not considered elementals, but leptons have no structure and they are thus truly elementary. There are six types (also so-called flavors) for quarks and leptons. Leptons can exist being isolated but quarks are always associated in three (baryons) or in pairs quark and antiquark (mesons). Protons and neutrons are the most known baryons and pions and kaons are the most known mesons.
Quarks only exist inside hadrons because they are confined by the strong force fields. Therefore, we cannot measure their mass by isolating them. The nature of the strong force between quarks does not permit isolated individual quarks to exist. This is a radically new feature of the strong force, never before encountered, but understandable in terms of the details of the strong forces characteristics.

All particles are classed as either fermions or bosons . The difference among them is due to their spin _____________________ Fermion: name for a particle that is a matter constituent, characterized by spin in odd half integer quantum units (1/2,3/2,5/2...). Named for Italian physicist Enrico Fermi. Quarks, leptons and baryons are all fermions. Fermions, cannot occupy the same quantum state as each other. They obey the Fermi-Dirac statistics and the Pauli exclusion principle. They "resist" being placed close to each other. So, fermions possess "rigidness" and thus sometimes are considered to be "particles of matter". The Pauli exclusion principle obeyed by fermions is responsible for the stability of the electron shells of atoms (thus for stability of atomic matter). It also is responsible for the complexity of atoms (making it impossible for all atomic electrons to occupy the same energy level), thus making complex chemistry possible. It is also responsible for the pressure within degenerate matter which largely governs the equilibrium state of white dwarfs and neutron stars. ______________________________________________________________ Boson: name for any particle with a spin of an integer number ( 0,1 or 2...) of quantum units of angular momentum. (named for Indian physicist S.N. Bose). The carrier particles of all interactions are bosons. Mesons are also bosons. In contrast to fermions, several bosons can occupy the same quantum state. Thus, bosons with the same energy can occupy the same place in space. The only two bosons in the Standard Model that are yet to be discovered experimentally are the Higgs boson and the graviton. The properties of lasers and masers, superfluid helium-4 and Bose–Einstein condensates are all consequences of statistics of bosons.