by Frank Close
Particle Physics: A Very Short Introduction
VERY SHORT INTRODUCTIONS are for anyone wanting a stimulating and accessible way in to a new subject. They are written by experts, and have been published in more than 25 languages worldwide.
The series began in 1995, and now represents a wide variety of topics in history, philosophy, religion, science, and the humanities. Over the next few years it will grow to a library of around 200 volumes – a Very Short Introduction to everything from ancient Egypt and Indian philosophy to conceptual art and cosmology.
Very Short Introductions available now:
ANCIENT PHILOSOPHY Julia Annas
THE ANGLO-SAXON AGE John Blair
ANIMAL RIGHTS David DeGrazia
ARCHAEOLOGY Paul Bahn
ARCHITECTURE Andrew Ballantyne
ARISTOTLE Jonathan Barnes
ART HISTORY Dana Arnold
ART THEORY Cynthia Freeland
THE HISTORY OF ASTRONOMY Michael Hoskin
ATHEISM Julian Baggini
AUGUSTINE Henry Chadwick
BARTHES Jonathan Culler
THE BIBLE John Riches
BRITISH POLITICS Anthony Wright
BUDDHA Michael Carrithers
BUDDHISM Damien Keown
CAPITALISM James Fulcher
THE CELTS Barry Cunliffe
CHOICE THEORY Michael Allingham
CHRISTIAN ART Beth Williamson
CLASSICS Mary Beard and John Henderson
CLAUSEWITZ Michael Howard
THE COLD WAR Robert McMahon
CONTINENTAL PHILOSOPHY Simon Critchley
COSMOLOGY Peter Coles
CRYPTOGRAPHY Fred Piper and Sean Murphy
DADA AND SURREALISM David Hopkins
DARWIN Jonathan Howard
DEMOCRACY Bernard Crick
DESCARTES Tom Sorell
DRUGS Leslie Iversen
THE EARTH Martin Redfern
EGYPTIAN MYTH Geraldine Pinch
EIGHTEENTH-CENTURY BRITAIN Paul Langford
THE ELEMENTS Philip Ball
EMOTION Dylan Evans
EMPIRE Stephen Howe
ENGELS Terrell Carver
ETHICS Simon Blackburn
THE EUROPEAN UNION John Pinder
EVOLUTION Brian and Deborah Charlesworth
FASCISM Kevin Passmore
THE FRENCH REVOLUTION William Doyle
FREUD Anthony Storr
GALILEO Stillman Drake
GANDHI Bhikhu Parekh
GLOBALIZATION Manfred Steger
HEGEL Peter Singer
HEIDEGGER Michael Inwood
HINDUISM Kim Knott
HISTORY John H. Arnold
HOBBES Richard Tuck
HUME A. J. Ayer
IDEOLOGY Michael Freeden
INDIAN PHILOSOPHY Sue Hamilton
INTELLIGENCE Ian J. Deary
ISLAM Malise Ruthven
JUDAISM Norman Solomon
JUNG Anthony Stevens
KANT Roger Scruton
KIERKEGAARD Patrick Gardiner
THE KORAN Michael Cook
LINGUISTICS Peter Matthews
LITERARY THEORY Jonathan Culler
LOCKE John Dunn
LOGIC Graham Priest
MACHIAVELLI Quentin Skinner
MARX Peter Singer
MATHEMATICS Timothy Gowers
MEDIEVAL BRITAIN John Gillingham and Ralph A. Griffiths
MODERN IRELAND Senia Pašeta
MOLECULES Philip Ball
MUSIC Nicholas Cook
NIETZSCHE Michael Tanner
NINETEENTH-CENTURY BRITAIN Christopher Harvie and H. C. G. Matthew
NORTHERN IRELAND Marc Mulholland
PARTICLE PHYSICS Frank Close
PAUL E. P. Sanders
PHILOSOPHY Edward Craig
PHILOSOPHY OF SCIENCE Samir Okasha
PLATO Julia Annas
POLITICS Kenneth Minogue
POLITICAL PHILOSOPHY David Miller
POSTCOLONIALISM Robert Young
POSTMODERNISM Christopher Butler
POSTSTRUCTURALISM Catherine Belsey
PREHISTORY Chris Gosden
PRESOCRATIC PHILOSOPHY Catherine Osborne
PSYCHOLOGY Gillian Butler and Freda McManus
QUANTUM THEORY John Polkinghorne
ROMAN BRITAIN Peter Salway
ROUSSEAU Robert Wokler
RUSSELL A. C. Grayling
RUSSIAN LITERATURE Catriona Kelly
THE RUSSIAN REVOLUTION S. A. Smith
SCHIZOPHRENIA Chris Frith and Eve Johnstone
SCHOPENHAUER Christopher Janaway
SHAKESPEARE Germaine Greer
SOCIAL AND CULTURAL ANTHROPOLOGY John Monaghan and Peter Just
SOCIOLOGY Steve Bruce
SOCRATES C. C. W. Taylor
SPINOZA Roger Scruton
STUART BRITAIN John Morrill
TERRORISM Charles Townshend
THEOLOGY David F. Ford
THE TUDORS John Guy
TWENTIETH-CENTURY BRITAIN Kenneth O. Morgan
WITTGENSTEIN A. C. Grayling
WORLD MUSIC Philip Bohlman
Available soon:
AFRICAN HISTORY John Parker and Richard Rathbone
ANCIENT EGYPT Ian Shaw
THE BRAIN Michael O’Shea
BUDDHIST ETHICS Damien Keown
CHAOS Leonard Smith
CHRISTIANITY Linda Woodhead
CITIZENSHIP Richard Bellamy
CLASSICAL ARCHITECTURE Robert Tavernor
CLONING Arlene Judith Klotzko
CONTEMPORARY ART Julian Stallabrass
THE CRUSADES Christopher Tyerman
DERRIDA Simon Glendinning
DESIGN John Heskett
DINOSAURS David Norman
DREAMING J. Allan Hobson
ECONOMICS Partha Dasgupta
EXISTENTIALISM Thomas Flynn
THE FIRST WORLD WAR Michael Howard
FREE WILL Thomas Pink
FUNDAMENTALISM Malise Ruthven
HABERMAS Gordon Finlayson
HIEROGLYPHS Penelope Wilson
HIROSHIMA B. R. Tomlinson
HUMAN EVOLUTION Bernard Wood
INTERNATIONAL RELATIONS Paul Wilkinson
JAZZ Brian Morton
MANDELA Tom Lodge
MEDICAL ETHICS Tony Hope
THE MIND Martin Davies
MYTH Robert Segal
NATIONALISM Steven Grosby
PERCEPTION Richard Gregory
PHILOSOPHY OF RELIGION Jack Copeland and Diane Proudfoot
PHOTOGRAPHY Steve Edwards
THE RAJ Denis Judd
THE RENAISSANCE Jerry Brotton
RENAISSANCE ART Geraldine Johnson
SARTRE Christina Howells
THE SPANISH CIVIL WAR Helen Graham
TRAGEDY Adrian Poole
THE TWENTIETH CENTURY Martin Conway
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PARTICLE PHYSICS
A Very Short Introduction
Frank Close
Great Clarendon Street, Oxford OX2 6DP
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Published in the United States by Oxford University Press Inc., New York
© Frank Close, 2004
The moral rights of the author have been asserted Database right Oxford University Press (maker)
First published as a Very Short Introduction 2004
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British Library Cataloguing in Publication Data
Data available
Library of Congress Cataloging in Publication Data
Particle physics: a very short introduction / Frank Close. (Very short introductions)
Includes bibliographical references and index.
ISBN 0–19–280434–0
1. Particles (Nuclear physics)—Popular works. I. Title. II Series.
QC778.C56 2004
539.7′2—dc22 2004049295
ISBN 0–19–280434–0
1 3 5 7 9 10 8 6 4 2
Typeset by RefineCatch Ltd, Bungay, Suffolk
Printed in Great Britain by
TJ International Ltd., Padstow, Cornwall
Contents
Foreword
List of illustrations and tables
1 Journey to the centre of the universe
2 How big and small are big and small?
3 How we learn what things are made of, and what we found
4 The heart of the matter
5 Accelerators: cosmic and manmade
6 Detectors: cameras and time machines
7 The forces of Nature
8 Exotic matter (and antimatter)
9 Where has matter come from?
10 Questions for the 21st century
Further reading
Glossary
Index
Foreword
We are made of atoms. With each breath you inhale a million billion billion atoms of oxygen, which gives some idea of how small each one is. All of them, together with the carbon atoms in your skin, and indeed everything else on Earth, were cooked in a star some 5 billion years ago. So you are made of stuff that is as old as the planet, one-third as old as the universe, though this is the first time that those atoms have been gathered together such that they think that they are you.
Particle physics is the subject that has shown how matter is built and which is beginning to explain where it all came from. In huge accelerators, often several miles in length, we can speed pieces of atoms, particles such as electrons and protons, or even exotic pieces of antimatter, and smash them into one another. In so doing we are creating for a brief moment in a small region of space an intense concentration of energy, which replicates the nature of the universe as it was within a split second of the original Big Bang. Thus we are learning about our origins.
Discovering the nature of the atom 100 years ago was relatively simple: atoms are ubiquitous in matter all around, and teasing out their secrets could be done with apparatus on a table top. Investigating how matter emerged from Creation is another challenge entirely. There is no Big Bang apparatus for purchase in the scientific catalogues. The basic pieces that create the beams of particles, speed them to within an iota of the speed of light, smash them together, and then record the results for analysis all have to be made by teams of specialists. That we can do so is the culmination of a century of discovery and technological progress. It is a big and expensive endeavour but it is the only way that we know to answer such profound questions. In the course of doing so, unexpected tools and inventions have been made. Antimatter and sophisticated particle detectors are now used in medical imaging; data acquisition systems designed at CERN (the European Organization for Nuclear Research) led to the invention of the World Wide Web – these are but some of the spin-off from high-energy particle physics.
The applications of the technology and discoveries made in high-energy physics are legion, but it is not with this technological aim that the subject is pursued. The drive is curiosity; the desire to know what we are made of, where it came from, and why the laws of the universe are so finely balanced that we have evolved.
In this Very Short Introduction I hope to give you a sense of what we have found and some of the major questions that confront us at the start of the 21st century.
List of illustrations and tables
1 Inside the atom
2 The forces of Nature
3 Comparisons with the human scale and beyond normal vision
4 Correspondence between scales of temperature and energy in electronvolts
5 Energy and wavelength
6 Result of heavy and light objects hitting light and heavy targets, respectively
7 Properties of up and down quarks
8 Quark spins and how they combine
9 Beta decay of a neutron
10 Fundamental particles of matter and their antiparticles
11 First successful cyclotron, built in 1930
Photo: Lawrence Berkeley National Laboratory. Illustration: © Gary Hincks