Тяжёлые адроны ФИАН / 2

Flavor Physics

Тяжелые адроны

лекция 2

Sergey Polikarpov

1

Overview

2

Brief plan

Some history lessons

Beta decayParity (violation)Nuclear forces

Observation of pions and strange particlesC-parity, CP violation in kaon systemMuon and tau

CP violation in neutral meson system

In beauty, charm, strange(rem.)

CKM matrixSpectroscopy

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History: Rutherford experiment 1911

Demonstrated that atoms have very compact nuclei

[Much of an atom's positive charge is concentrated in a

relatively tiny volume at the center of the atom]

→

Rutherford model of nuclei

The atom itself is about 100,000 (105) times the diameter of the nucleus

→ “measure” nuclei charge

→ X-ray can measure electron number

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History: atom/nuclei decays

Each individual process has monochromatic spectrum

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History: atom/nuclei decays

Also, β+ and electron capture processes were observed.

In case of β+ processes, electron capture was always

“competing” with it.

WHY?

The opposite was not true, however. WHY?

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How to solve the β-decay problem?

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How to solve the β-decay problem?

Pauli, 1930

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Neutron discovery (1930)

with large energy ~5 MeV

Q: why not γ?

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4-fermion interaction

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