Wednesday, March 23, 2011

Notes 1

Big experiments with hundreds of physicists and tens of organizations involved.
The process for scientific grant application was minimal
Discussion of JJ Thompson
Rutherford's "discovery" of the atomic nucleus - it was considered an utter failure as nobody outside Manchester paid any attention. This was in 1911.
Plagiarism in physics

Quatenspringerei, anno 1913.
1928: quantum mechanics valid for the atomic nucleus
Zur Quantentheorie des Atomkernes Yves G Gamow

The neutron was discovered in the 1932.
Chadwick thought that the elementary neutron 'had little to recommend it'
The original neutron source.

The Quantum Theory of the Electron by P.A.M. Dirac
Quantised Singularities in the Electromagnetic Field by P.A.M. Dirac (antiparticles and magnetic monopoles)
Dirac's relativistic wave equations leads formally to solutions with negative energy, which he interpreted as 'holes' in a 'sea' of negative energy electrons - and identified with protons. He thought the antielectron = proton hypothesis was the realization of the 'dream of the philosophers.'

If two-particle decay, spectrum must be discrete as electrons are emitted from the nuclei. Bohr suggested violation of energy conservation, and he was supported by Gamow, Landau, and Others. Pauli, on the other hand, proposed the existence of a spin 1/2 'neutron,' pre-existing in the nucleus and with mass 'of the same order of magnitude as the electron mass'

Constitution of Atomic Nuclei and Radioactivity, 1931, George Gamow
"Does the Neutrino really Exist?"  by SM Dancoff for the Bulletin for Atomic Scientists 8 (1852), 139-141
The detection of neutrinos
Using a nuclear reactor as a neutron source, in 1956 F. Reines and C. Cowan found signals from the reaction
V+p---> n + e+

Yukawa's U-quanta m ~ 200 me mediated the nuclear force. But did they exist?

Importance of the properties of the particles.
Fermion Masses:
It is important for experimental future that the masses of electrons not be negligible.
perturbative and non-perturbative techniques.
Lack full completely analytical proof of quark, or color confinement.

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