Nuclear and Particle Physics

Contact Details Course Organisers Daniel Watts (Nuclear Physics) [email protected] JCMB Room 8209 Tel: 0131 650 5254 http://www.ph.ed.ac.uk/~dwatts1

Dr Daniel Watts

3rd Year Junior Honours Course Mondays & Thursdays 10am

Victoria Martin (Particle Physics) [email protected] JCMB Room 4405 Tel: 0131 651 7042 Course handouts will be available on course web portal after each lecture (useful as in colour!)

Tutorial arrangements 1 tutorial every two lectures. Class split into two groups. Start on Mon 14th January

Mondays 12:10 – 13:00 Room 5327, JCMB All Astro students

Tuesday 14:00 – 14:50 Room 3317, JCMB All other students Group problem solving with Lecturer & Postdoctoral research assistant

Notes

Notes

Industry power plants energy source materials tracing

Research Military

condensed matter element analysis (bio)chemistry

nuclear weapons

Nuclear Physics Medicine

Archaeology & Geology

computed tomography magnetic resonance imaging radiation therapy

dating analysis

Astrophysics energy production in stars nucleosynthesis of elements

LIFE

Today’s nuclear physics research

My Research interests

Hadron Structure: The structure of the nucleon and of hadrons in general

Heavy Ion Physics: Quark-gluon plasma, new phases of matter

Using electromagnetic probes (intense photon/electron beams) to probe matter from scale of atomic nuclei down to nucleons and quarks. In Germany www.kph.uni-mainz.de, USA www.jlab.org and Sweden www.maxlab.lu.se. Research topics include:

Nuclear Astrophysics: Understanding stars, super-novae etc.

• Structure of the proton and neutron

Exotic Nuclei: Nuclei far from stability

• Violent short range nucleon-nucleon interactions in nuclei

Use a wide variety of particle detection systems

• Three-nucleon forces in nuclei

Hadron Spectroscopy: The search for “glueballs”, “hybrids”, multiquark states

High intensity superconducting electron Accelerator (Jefferson Lab)

Large acceptance magnetic spectrometers High precision magnetic spectrometers

Hyper pure Ge arrays

Large acceptance magnetic spectrometers

Large acceptance high energy γ detectors

Notes

Course layout Third year

nuclear force

binding energies

properties

models

radioactivity

NUCLEUS

structure

applications

nuclear reactions

models astrophysics medicine industry … Fourth year

Notes

Nuclear Physics Course Outline • Introduction and basic concepts Brief historical overview The nucleus and its constituents Nomenclature The forces of nature Basic concepts of quantum mechanics

• Nuclear properties External: mass, charge, size, mass and charge distribution Internal: angular momentum, spin, parity, magnetic moment excited states

• Nuclear structure Masses and binding energies Semi-empirical mass formula The beta stability valley Properties of nuclear forces

• Nuclear models Liquid drop model Shell model and evidence for shell structure Single particle features Magic numbers, spin-orbit coupling Predicted angular momenta of nuclear ground states Collective model. Vibrational and rotational states

• Nuclear instability Occurrence and stability of nuclei α- β- γ- decay modes

Suggested textbooks J. Lilley

Nuclear physics Principles and applications John Wiley and Sons, 2001 Clear and concise. Not too advanced, makes a very good starting point. Interesting chapters on applications

W.N. Cottingham and D.A Greenwood

An introduction to nuclear physics Oxford Science Publications, 1997 Nicely concise and still rich in content.

K.S. Krane

Introductory nuclear physics John Wiley and Sons, 1988 Very didactic and clear. The textbook for the more advanced, dedicated student. R. Eisberg and R. Resnick

Quantum physics of atoms, molecules, solids, nuclei and particles John Wiley and Sons, 1985 Exceptionally clear + very didactic. Optimum for review of quantum ideas in atomic & nuclear physics

P.E. Hodgson, E. Gadioli and E. Gadioli Erba

Introductory nuclear physics Oxford Science Publications, 1997 Very comprehensive + somewhat more advanced. Deeper mathematical treatment

Notes

Notes

Brief historical overview In search of the building blocks of the universe… Greek philosophers

earth

4 building blocks 5th BC - Democritus

water

atomic hypothesis

18th-19th century Lavoisier, Dalton, … put atomic hypothesis on firm basis distinction between compounds and pure elements

1896 Mendeleev 92 building blocks (chemical elements) 1H, 2He,

…92U

1896 Becquerel discovers radioactivity ⇒ emission of radiation from atoms ⇒ 3 types observed: α, β and γ

α and β deflected in opposite direction ⇒ opposite charge α deflected less than β ⇒ α must have larger mass γ not deflected ⇒ uncharged

air

fire

Notes

Notes

~1900 Rutherford investigates new radiations α and β emissions change nature of element α‘s charge = +2e α’s mass ~ 4H β radiation = electrons γ = electromagnetic radiation (photons)

1911 Rutherford tests Thomson’s model of the atom

Conclusion: all +ve charge (and ~all mass) concentrated in tiny region at the centre Concept of atomic NUCLEUS is born ! Atom = nucleus + electron

-e

planetary model of atom (10-10 m)

Clear experimental evidence that atoms contain electrons – where are they? Heisenberg ⇒ simplest atom = H

“plum pudding model”

use α particles (positively charged) on golden foil

+ve α’s pushed a little to the side by +ve charge of atom

mass

charge

He ~ 4 H C ~ 12 H O ~ 16 H ….

He = 2 H C =6H O =8H ….

observed some α’s deflected backwards to 180o !!

⇒ hypothesis of neutral particle in nucleus with m ~ mp

1932 Chadwick discovers the neutron 3 building blocks electron + proton + neutron

In Rutherford’s own words: “…it was as incredible as if you had fired a 15-inch shell at a piece of tissue paper and it came back and hit you”

its nucleus = proton

1920 Aston’s mass spectrograph ⇒ measure masses of atoms -ve electrons embedded in +ve charge uniformly distributed over atomic volume

expected

+Ze

Nucleus = protons + neutrons

NUCLEAR PHYSICS (10-15 m)

1934 Joliot, Curie - Artificial radioactivity 1940 Flerov, Petrjak - Spontaneous fission

Notes

Notes

Origin of nuclear matter (Background) Universe goes through superfast inflation

10-43s 10-32s

1027 oC

Post inflation – soup of electrons, quarks and other particles

10-6s

1013 oC

Quarks clump into protons and neutrons

102 s

108 oC

Superhot fog (protons and electrons not yet bound into atoms). Primordial nucleosysnthesis (up to 4He)

3x105 yr

1x109 yr 15x109 yr

Energy, time and density scales

105 oC

-200 oC -270 oC

Electrons combine with protons and neutrons to form atoms (H, He) Star/Galaxy formation synthesis of heavier nuclei First stars die and eject heavy nuclei into space – further star formation (and planets)

Typical energy scale in nuclei (MeV) is much higher than in atomic case (eV). Lifetimes of excited states are typically of order 10-12 s compared with 10-8 s for atomic physics

Nuclei are dense objects: 1cm3 has mass ~ 2.3x1011 kg (equivalent to 630 empire state buildings!!)

The collisions of nucleons in the nucleus are rarely of sufficient energy to excite the protons/neutrons ∴ they are a very effective degree of freedom to describe nuclei White Dwarf

100

Time

Neutron star

Solid state

water

105

1010

Black hole

3 1015 g/cm density

Nuclear matter