Particle Physics

541 Pages·2014·4.73 MB·English

by  Anwar Kamal (auth.)

Graduate Texts in Physics
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Graduate Texts in Physics
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ProfessorMartinStutzmann
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Anwar Kamal
Particle Physics
AnwarKamal(deceased)
Murphy,TX,USA
ISSN1868-4513 ISSN1868-4521(electronic)
GraduateTextsinPhysics
ISBN978-3-642-38660-2 ISBN978-3-642-38661-9(eBook)
DOI10.1007/978-3-642-38661-9
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Preface
This is an introductory textbook of particle physics for upper undergraduate stu-
dents.ThebookisbasedonlecturesgivenatBritish,AmericanandIndianUniver-
sitiesoverseveralyears.Theideaofwritingatextbookonthissubjectwasmooted
somefortyyearsago.Butitwasnevereasytowriteonasubjectlikeparticlephysics
whichstartedexpandingexplosivelyinsixtiesandseventies.Allthishappeneddue
tothedevelopmentofhighenergyacceleratorsandsophisticateddetectingsystems
ontheexperimentalside,paralleledbynewconceptsonthetheoreticalside.Andit
becameverydifficulttokeeppacewiththerapidlychangingscenario.Now,when
thedustissettleddownandtheunderlinedphysicsisunderstoodinabigway,al-
though quite a bit is still obscure, there appears a justification in expounding the
basic ideas of particle physics in the form of a textbook. It is attempted to survey
the major developments in particle physics during the past 100 years. In Ruther-
ford’s time and early 1950s, only a few Elementary particles were known and the
existence of neutrino was taken for granted. At that time, the entire knowledge of
elementaryparticlesandcosmicrayswassoscantythatitcouldbeaccommodated
inasinglechapter.But,afewdecadesago,particlephysicsbranchedofffromnu-
clearphysicsandbecamevirtuallyanindependentdiscipline.Notextbookwould
bebalanceduntilequalweightageisgiventothesetwodisciplines.Thereisalsoa
complementarytextbookonnuclearphysicsavailablebythesameauthor.
Thedevelopmentofthesubjectissofascinatingthatwewereinclinedtopresent
the historical facts in the chronological order. The prerequisites for the use of this
book are the elements of quantum mechanics comprising Schrodinger’s equation
andapplications,Born’sapproximation,thegoldenrule,differentialequationsand
VectorCalculus.
Basicconceptsareexplainedwithlinediagramswhereverrequired.Anattempt
ismadetostrikeabalancebetweentheoryandexperiment.Theoreticalpredictions
arecomparedwithlatestobservationstoshowagreementordiscrepancieswiththe
theory.Thesubjectmatterisdevelopedineachchapterwithnecessarymathematical
details.Feynmandiagramsareusedextensivelytoexplainthefundamentalinterac-
tions.
vii
viii Preface
Thesubjectmatterinvariouschaptersissomuchintimatelyconnectedthatthe
logicalsequentialpresentationofvarioustopicsbecomesavexingproblem.Forex-
ample,fromthepointofviewofintroducingquarks,thelogicalsequencewouldbe
strong, electromagnetic, weak and electroweak interactions, but from the point of
viewofintroducingFeynman’sdiagrams,thedesirablesequencewouldbeelectro-
magnetic,weak,electroweakandstronginteractions,whichiswhyonefindsvari-
ance in sequences for both Nuclear and Particle physics in various textbooks. The
onlyremedyistomakecrossreferencestothechapterswhichwerestudiedbefore
andtothoseinwhichtherelevantmaterialisanticipated.
Attheendofeachchapter,asetofquestionsisgiven.Alargenumberofworked
examplesaregiven.Acomparablenumberofunworkedproblemswithanswersis
delivered in the book to test the understanding of the student. The examples and
problemsarenotnecessarilyofplug-intypebutaregiventoexplaintheunderlying
physics.Varioususefulappendicesareprovidedattheendofthebook.
Murphy,TX AnwarKamal
Note: These two volumes are the last books by my father Dr. Ahmad Kamal, the
work he had conceivedas his dream project and indeed his scientific masterpiece.
Unfortunately, he passed away before he could see his manuscript in print. While
wehavetriedourbesttobringthepublishingprocesstoassatisfactoryconclusion
as possible, we regret any errors you may discover, in particular, that some of the
referencescouldnotbeascompletelyspecificallycitedaswouldotherwisebethe
case.Wetrustthattheseerrorshoweverdonotcompromisethequalityorstandard
ofthecontentofthetext.
SuraiyaKamal
DaughterofDr.AhmadKamal
Acknowledgements
I am grateful to God for helping us to complete the dream project of Dr. Ahmad
Kamalafterhisdemise,whichseemedverydifficultandevenimpossibleattimes.
IwouldliketothankSpringer-Verlag,inparticularDr.ClausAsheron,Mr.Do-
natas Akmanavicˇius, Ms. Adelheid Duhm and Ms. Elke Sauer for their constant
encouragement,patience,cooperation,andforbringingthebooktoitscurrentform.
Thisprojectwouldnotbecompletewithouttheconstantsupportandencourage-
mentofMrs.MaryamKamal,wifeofDr.AhmadKamal.Herdeterminationkeptus
allmovingtogetthesebooksdone.Mysincerethanksisduetothefamily,friends
andwell-wishersoftheauthorwhohelpedandprayedforthecompletionofthese
books.
SuraiyaKamal
DaughterofDr.AhmadKamal
ix
Contents
1 NuclearRadiationDetectors . . . . . . . . . . . . . . . . . . . . . . 1
1.1 ClassificationofDetectors . . . . . . . . . . . . . . . . . . . . . 1
1.2 IonizationChambers . . . . . . . . . . . . . . . . . . . . . . . . 3
1.2.1 IonizationChambers . . . . . . . . . . . . . . . . . . . 3
1.2.2 PulseChambers. . . . . . . . . . . . . . . . . . . . . . 3
1.2.3 Gas-FilledPulseCounter . . . . . . . . . . . . . . . . . 4
1.2.4 VariationofPulseSizes . . . . . . . . . . . . . . . . . 5
1.3 ProportionalCounter. . . . . . . . . . . . . . . . . . . . . . . . 7
1.3.1 Construction . . . . . . . . . . . . . . . . . . . . . . . 7
1.4 GeigerMullerCounter . . . . . . . . . . . . . . . . . . . . . . . 7
1.4.1 ConstructionandCharacteristics . . . . . . . . . . . . . 7
1.4.2 PulseFormationandDecay . . . . . . . . . . . . . . . 9
1.4.3 QuenchingtheDischarge . . . . . . . . . . . . . . . . . 10
1.4.4 ScalingCircuits . . . . . . . . . . . . . . . . . . . . . . 12
1.5 ResolvingTime . . . . . . . . . . . . . . . . . . . . . . . . . . 12
1.5.1 DeterminationofResolvingTime:
DoubleSourceMethod . . . . . . . . . . . . . . . . . . 13
1.6 ResolvingTimeofaCoincidenceCircuit . . . . . . . . . . . . . 14
1.6.1 DeterminationoftheResolvingTime
oftheCoincidenceCircuit . . . . . . . . . . . . . . . . 14
1.7 Semi-conductorParticleDetectors . . . . . . . . . . . . . . . . 19
1.7.1 Resolution . . . . . . . . . . . . . . . . . . . . . . . . 19
1.7.2 ReversedBiasedp-nJunctionParticleDetector . . . . . 19
1.7.3 Advantages . . . . . . . . . . . . . . . . . . . . . . . . 21
1.7.4 Applications . . . . . . . . . . . . . . . . . . . . . . . 22
1.7.5 Disadvantages . . . . . . . . . . . . . . . . . . . . . . 22
1.8 NeutronDetectors . . . . . . . . . . . . . . . . . . . . . . . . . 23
1.8.1 Principle . . . . . . . . . . . . . . . . . . . . . . . . . 23
1.8.2 DesiredCharacteristicsofNeutronDetectors . . . . . . 24
1.8.3 SlowNeutronDetectors . . . . . . . . . . . . . . . . . 24
1.8.4 FissionDetectors . . . . . . . . . . . . . . . . . . . . . 27
xi