Rabu, 26 Maret 2014

Particle physics - Subatomic Particles - Field theory


Particle physics is a branch of physics that studies the elementary subatomic constituents of particles of matter and radiation, and the interactions between them. He is also called high energy physics, because many elementary particles do not occur under normal circumstances in nature, but can be created and detected during energetic collisions of other particles, as is done in particle accelerators.

Subatomic Particles

Advanced particle physics research is focused on the Sub-Atomic particles, including atomic constituents such as electrons, protons, and neutrons (protons and neutrons are actually composite particles made up of quarks), particles produced by radioactive and scattering processes, such as photons, neutrinos, and muons, as well as a wide range of exotic particles.

Actually, the term particle is a misnomer because the dynamics of particle physics are governed by quantum mechanics. As such, they exhibit wave-particle duality, such as particles in the experiment and conditions such as seubah in wave conditions other circumstances (more technically they are described by State vectors in a Hilbert space; see quantum field theory). Following the Convention of particle physicists, "elementary particles" refer to objects such as electrons and photons and "particles" display wave-like properties as well.

All the particles and their interactions were observed until the present can be described entirely by a quantum field theory called the standard Model. The standard Model has 17 species of elementary particles: 12 fermions (24 if you count antiparticles separately), 4 vector bosons (5 If you count antiparticles separately), and 1 scalar bosons. This basic particles can combine to form composite particles, which now reach hundreds of its kind since the first composite particle found in the 1960s. the standard Model has been found to conform to almost any test experiments conducted at the moment. However, most particle physicists believe that this model is still not able to give a complete explanation of nature, and that there is a more fundamental theory. In recent years, the size of the neutrino mass have provided the first experimental deviations from the standard Model.

History

The idea that all matter is composed of elementary particles starting from at least the 6th century BC philosophical doctrine of atomism and the nature of elementary particles were studied by Philosophers of ancient Greece such as Democritus, Epicurus and Democritus, philosophers of ancient India such as Dignaga and Dharmakirti, Canada; medieval scientists such as Alhazen, Avicenna and Algazel; and early European modern physicists such as Pierre Gassendi, Robert Boyle and Isaac Newton. Particle theory of light was also proposed by Alhazen, Avicenna, Gassendi and Newton. Early ideas were founded in abstract, philosophical reasoning rather than experimentation and empirical observation.

In the 19th century, John Dalton, through his work on stoichiometry, concluded that every natural element is composed of one type of particle that is unique. Dalton and his contemporaries believed these were the fundamental particles of nature and thus named them atoms, from the word Greece atomos, meaning "indivisible". However, near the end of the century, physicists discovered that the atom is apparently not fundamental particles of nature, but a combination of particles smaller particle. Research of nuclear physics and quantum physics in the early 20th century culminated in proofs of nuclear fission in 1939 by Lise Meitner (based on experiments by Otto Hahn), and nuclear fusion by Hans Bethe in the same year. These discoveries gave rise to an active industry for generating one atom from another, possibly even doing (although not profitable) the transmutation of lead into gold. They also lead to the development of nuclear weapons. Throughout the 1950s and 1960s, various particle Scattering experiments found that referred to as the "particle Zoo". This term has been abandoned after the formulation of the standard Model during the 1970s in which a large number of particles, it is described as a combination of a number of fundamental particles.

Field theory

Field theory is a theory of physics to study the dynamics of elementary particles by assuming the particles as the terrain.

Tidak ada komentar:

Posting Komentar