內容簡介
《粒子物理學標準模型導論(第2版)》從介子和誇剋的電磁作用和弱相互作用開始,講到瞭誇剋的強相互作用,內容層層深入。介紹標準模型的同時,作者非常注重選材的可進階性,方便讀者更深入的研讀。
內頁插圖
目錄
Preface to the second edition
Preface to the first edition
Notation
1 The particle physicists view of Nature
1.1 Introduction
1.2 The construction of the Standard Model
1.3 Leptons
1.4 Quarks and systems of quarks
1.5 Spectroscopy of systems of light quarks
1.6 More quarks
1.7 Quark colour
1.8 Electron scattering from nucleons
1.9 Particle accelerators
1.10 Units
2 Lorentz transformations
2.1 Rotations, boosts and proper Lorentz transformations
2.2 Scalars, contravariant and covariant four-vectors
2.3 Fields
2.4 The Levi-Civita tensor
2.5 Time reversal and space inversion
3 The Lagrangian formulation of mechanics
3.1 Hamiltons principle
3.2 Conservation of energy
3.3 Continuous systems
3.4 A Lorentz covariant field theory
3.5 The Klein-Gordon equation
3.6 The energy-momentum tensor
3.7 Complex scalar fields
4 Classical electromagnetism
4.1 Maxwells equations
4.2 A Lagrangian density for electromagnetism
4.3 Gauge transformations
4.4 Solutions of Maxwells equations
4.5 Space inversion
4.6 Charge conjugation
4.7 Intrinsic angular momentum of the photon
4.8 The energy density of the electromagnetic field
4.9 Massive vector fields
5 The Dirac equation and the Dirac field
5.1 The Dirac equation
5.2 Lorentz transformations and Lorentz invariance
5.3 The parity transformation
5.4 Spinors
5.5 The matrices
5.6 Making the Lagrangian density real
6 Free space solutions of the Dirac equation
6.1 A Dirac particle at rest
6.2 The intrinsic spin of a Dirac particle
6.3 Plane waves and helicity
6.4 Negative energy solutions
6.5 The energy and momentum of the Dirac field
6.6 Dirac and Majorana fields
6.7 The E ] ] m limit, neutrinos
7 Electrodynamics
7.1 Probability density and probability current
7.2 The Dirac equation with an electromagnetic field
7.3 Gauge transformations and symmetry
7.4 Charge conjugation
7.5 The electrodynamics of a charged scalar field
7.6 Particles at low energies and the Dirac magnetic moment
8 Quantising fields: QED
8.1 Boson and fermion field quantisation
8.2 Time dependence
8.3 Perturbation theory
8.4 Renornmalisation and renormalisable field theories
8.5 The magnetic moment of the electron
8.6 Quantisation in the Standard Model
9 The weak interaction: !ow energy phenomenology
9.1 Nuclear beta decay
9.2 Pion decay
9.3 Conservation of lepton number
9.4 Muon decay
9.5 The interactions of muon neutrinos with electrons
10 Symmetry breaking in model theories
10.1 Global symmetry breaking and Goldstone bosons
10.2 Local symmetry breaking and the Higgs boson
11 Massive gauge fields
11.1 SU(2) symmetry
11.2 The gauge fields
11.3 Breaking the SU(2) symmetry
11.4 Identification of the fields
12 The Weinberg——Salam electroweak theory for leptons
12.1 Lepton doublets and the Weinberg-Salam theory
12.2 Lepton coupling to the W
12.3 Lepton coupling to the Z
12.4 Conservation of lepton number and conservation of charge
12.5 CP symmetry
12.6 Mass terms in : an attempted generalisation
13 Experimental tests of the Weinberg——Salam theory
13.1 The search for the gauge bosons
13.2 The W bosons
13.3 The Z boson
13.4 The number of lepton families
13.5 The measurement of partial widths
13.6 Left-right production cross-section asymmetry and lepton decay symmetry of the Z boson
14 The electromagnetic and weak interactions of quarks
14.1 Construction of the Lagrangian density
14.2 Quark masses and the Kobayashi-Maskawa mixing matrix
14.3 The parameterisation of the KM matrix
14.4 CP symmetry and the KM matrix
14.5 The weak interaction in the low energy limit
15 The hadronic decays of the Z and W bosons
15.1 Hadronic decays of the Z
15.2 Asymmetry in quark production
15.3 Hadronic decays of the W
16 The theory of strong interactions: quantum chromodynamics
16.1 A local SU(3) gauge theory
16.2 Colour gauge transformations on baryons and mesons
16.3 Lattice QCD and asymptotic freedom
16.4 The quark-antiquark interaction at short distances
16.5 The conservation of quarks
16.6 Isospin symmetry
16.7 Chiral symmetry
17 Quantum chromodynamics: calculations
17.1 Lattice QCD and confinement
17.2 Lattice QCD and hadrons
17.3 Perturbative QCD and deep inelastic scattering
17.4 Perturbative QCD and e+e- collider physics
18 The Kobayashi-Maskawa matrix
18.1 Leptonic weak decays of hadrons
18.2 |Vud| and nuclear decay
18.3 More leptonic decays
18.4 CP symmetry violation in neutral kaon decays
18.5 B meson decays and B,B mixing
18.6 The CPTtheorem
……
精彩書摘
5、The Dirac equation and the Dirac field
The Standard Model is a quantum field theory.In Chapter 4 we discussed the classical electromagnetic field.The transition to a quantum field will be made in Chapter 8.In this chapter we begin our discussion of the Dirac equation,which was invented bv Dirac as an equation for the relativistic quantum wave function of a single electron.However,we shall regard the Dirac wave function as a field.Which will subsequently be quantised along with the electromagnetic field.The Dirace quationwillberegardedasafieldequation.Thetransitiontoaquantumfieldtheory
iS called second quantisation.The field。like the Dirac wave function.is complex.W_e shall show how the Dirac field transforms under a Lorentz transformation.And find a Lorentz invariant Lagrangian from which it may be derived.
On quantisation,the electromagnetic fields A(x),Fv(x)become space-and time.dependent 0perators.The expectation Values of these operators in the environ- ment described by the quantum states are the classical fields.The Dirac fields(x) alSO become space-and time.dependent operators on quantisation.However,there are no corresponding measurable classical fields.This di骶rence reflects the Pauli exclusion principle,which applies to fermions but not to bosons.In this chapter and in the following two chapters,the properties of the Dirac fields as operators are rarely invoked:for the most part the manipulations proceed as if the Dirac fields were ordinary complex functions,and the fields Can be thought of as single-particle Dirac wave functions.
5.1 The Dirac equation
Dirac invented his equation in seeking to make Schr6dingerS equation for an elec-tron compatible with special relativity.
前言/序言
In the eight years since the first edition, the Standard Model has not been seriously discredited as a description of particle physics in the energy region ([2 TeV) so far explored. The principal discovery in particle physics since the first edition is that neutrinos carry mass. In this new edition we have added chapters that extend the formalism of the Standard Model to include neutrino fields with mass, and we consider also the possibility that neutrinos are Majorana particles rather than Dirac particles.
The Large Hadron Collider (LHC) is now under construction at CERN. It is expected that, at the energies that will become available for experiments at the LHC (~20 TeV), the physics of the Higgs field will be elucidated, and we shall begin to see physics beyond the Standard Model. Data from the B factories will continue to accumulate and give greater understanding of CP violation. We are confident that interest in the Standard Model will be maintained for some time into the future.
Cambridge University Press have again been most helpful. We thank Miss V. K.Johnson for secretarial assistance. We are grateful to Professor Dr J. G. K6rner for his corrections to the first edition, and to Professor C. Davies for her helpful correspondence.
探尋物質最微小的構成,理解宇宙運行的基本法則 本書並非關於“粒子物理學標準模型導論(第2版)”這本書本身的介紹。它緻力於為您展現粒子物理學標準模型的魅力與深度,帶您踏上一段探尋宇宙最基本構成單元和支配它們相互作用之力的旅程。 我們生活在一個由無數粒子組成的宏觀世界,從浩瀚的星係到我們身體裏的細胞。然而,將目光聚焦到最微小的尺度,我們會發現,所有這一切的構成,都源於一群更為基礎的粒子,以及它們之間遵循的精妙規律。粒子物理學標準模型,正是我們目前對這一微觀世界最成功的理論框架。它像一本宇宙的“原子錶”,為我們列齣瞭構成物質的基本粒子,並描繪瞭四種基本力(引力除外)如何在這些粒子之間傳遞信息、引發相互作用。 構成物質的基石:費米子傢族 標準模型將所有基本粒子分為兩大類:費米子(構成物質的粒子)和玻色子(傳遞力的粒子)。在費米子傢族中,我們首先會深入瞭解誇剋。它們是構成質子和中子的基本單元,分為六種“味”(up, down, charm, strange, top, bottom)和三種“色”(red, green, blue)。正是這些不同“顔色”的誇剋,通過被稱為“強相互作用”的強大力量被束縛在一起,形成瞭我們熟悉的質子和中子。 除瞭誇剋,費米子傢族還包括輕子。最廣為人知的輕子莫過於電子,它是構成原子外殼,決定物質化學性質的關鍵。但電子並非孤軍奮戰,它還有與其相關的電子中微子。輕子傢族同樣擁有六種成員,按照質量和相互作用的規律,分為電子及其電子中微子,μ介子及其μ中微子,以及τ輕子及其τ中微子。這些粒子在宇宙的演化和各種物理過程中扮演著至關重要的角色,盡管中微子由於其極低的相互作用截麵,使得探測它們成為一項艱巨的挑戰。 傳遞力的信使:玻色子傢族 如果說費米子是構建宇宙的磚塊,那麼玻色子就是連接這些磚塊,並驅動宇宙運動的“膠水”和“信使”。標準模型描述瞭三種基本力(強力、弱力和電磁力)的傳遞方式,每種力都有其對應的玻色子。 膠子是傳遞強相互作用的粒子。它們的特性使得誇剋被緊密地束縛在質子和中子內部,即使在極高的能量下也很難將它們分離。我們無法單獨觀測到膠子,它們的存在完全由它們所傳遞的強力來體現。 光子是傳遞電磁相互作用的粒子。它是電磁波的量子,我們所見的陽光、無綫電波、X射綫等,都是光子的不同錶現形式。光子的無處不在,使得電磁力成為我們在日常生活中最為熟悉的相互作用。 W和Z玻色子是傳遞弱相互作用的粒子。雖然名為“弱”,但弱相互作用在某些過程中卻至關重要,例如太陽的能量産生,以及某些放射性衰變。W和Z玻色子具有質量,這使得它們在傳遞弱相互作用時,作用範圍相對較短。 賦予質量的奧秘:希格斯玻色子 然而,標準模型在解釋粒子質量的來源方麵,曾經遇到一個重大的難題。為什麼電子有質量,而光子卻沒有?如果所有基本粒子都沒有質量,那麼宇宙的結構將完全不同。直到希格斯機製的提齣,纔最終解決瞭這一謎團。 希格斯機製的核心在於存在一個遍布宇宙的希格斯場。基本粒子在穿越這個場時,會與場發生“相互作用”,這種相互作用的強弱程度,決定瞭粒子所獲得的質量大小。希格斯粒子(或稱希格斯玻色子),便是希格斯場的量子激發。它的發現,是粒子物理學領域的一項裏程碑式的成就,為標準模型提供瞭堅實的實驗支撐。 標準模型的成功與局限 標準模型憑藉其卓越的解釋能力,成功地描述瞭大量實驗數據,並精確預測瞭許多粒子現象。從粒子加速器中的碰撞實驗,到宇宙射綫的研究,都為標準模型提供瞭有力的證據。它解釋瞭原子為何穩定,化學反應為何發生,以及恒星為何能夠發光發熱。 盡管如此,標準模型並非終極理論。它仍然存在一些未解之謎和局限性。例如,標準模型並未包含引力,這使得它無法與廣義相對論統一。此外,它也無法解釋暗物質和暗能量的本質,這兩者構成瞭宇宙的大部分質量和能量。中微子質量的問題,以及是否存在比標準模型粒子更為基礎的構成單元,也仍然是科學傢們探索的前沿。 踏上探索之路 本書將引導您逐步理解這些基本粒子的性質、它們之間的相互作用,以及構成我們宇宙的宏偉圖景。我們將從介紹基本概念入手,逐步深入到各個粒子的傢族,以及四種基本力的量子理論描述。您將瞭解到,粒子物理學標準模型不僅僅是抽象的數學公式,更是我們理解物質起源、宇宙演化以及自然界最深層奧秘的有力工具。 這是一場關於微觀世界的壯麗探索,一次對宇宙基本規律的深刻洞察。準備好,跟隨我們一起,揭開物質最深處的麵紗,感受粒子物理學的無窮魅力。