Deep inelastic scattering

Deep inelastic scattering of a lepton on a hadron in leading order perturbation theory

The deep inelastic scattering is a scattering of an elementary high kinetic energy, z. B. an electron , muon or neutrino , on a nucleon with high energy and momentum transfer. In such scattering processes it is found that much more scattered electrons with low energy are detected than can be detected due to resonances of the nucleons, e.g. B. the Δ resonance expected. The deep inelastic scattering indicates that nucleons are made up of point-like constituents called partons . It turned out that the partons are the quarks postulated by Murray Gell-Mann . The interaction of the nucleons with the electrons takes place in quarks in the nucleon.

Scattering experiments

Physical scattering experiments provide information about the structure of particles. With the Rutherford scattering showed that an atom from a small, massive, positively charged nucleus and a lot of empty space is with the negatively charged electrons. In Rutherford scattering, the alpha particles do not emit any kinetic energy; it is an elastic scattering.

Deep inelastic scattering is inelastic scattering on nucleons; That is, the scattered particles give up kinetic energy to the nucleon. The scattered particles hit the nucleon with very high kinetic energy. The kinetic energy is chosen so that the De Broglie wavelength is much smaller than the size of the nucleon. The deep inelastic scattering gives information about the structure deep in the nucleon due to the sufficiently short wavelength of the scattering particles.

Electron-proton scattering

By scattering electrons on the proton, one tries to determine the dimensionless structure functions and . Here is the transmitted four-pulse and the Bjorken scaling . If the structure functions are not dependent on the quadruple momentum, this shows that the electrons are scattered at point-like constituents of the proton. ${\ displaystyle F_ {1} (x, Q ^ {2})}$ ${\ displaystyle F_ {2} (x, Q ^ {2})}$ ${\ displaystyle Q ^ {2}}$ ${\ displaystyle x}$

literature

B. Povh, K. Rith, C. Scholz, F. Zetsche: Particles and nuclei . 4th edition. Springer, 1997, ISBN 3-540-61737-X .

Individual evidence

↑ Jörn Bleck-Neuhaus: Elementary Particles. 2nd edition, Springer Spectrum 2013, ISBN 978-3-642-32578-6 , p. 602.

[1] Jörn Bleck-Neuhaus: Elementary Particles. 2nd edition, Springer Spectrum 2013, ISBN 978-3-642-32578-6 , p. 602.