Flavor physics: neutrinoproduction of resonances and semileptonic B → K, K_1hn* ll decays [Elektronische Ressource] / vorgelegt von Giorgi Piranishvili

Christoph Bobeth, P1-O4-306, 3498

Description

Flavor Physics:Neutrinoproduction of Resonances∗¯and Semileptonic B→K,K llDecaysDissertationzur Erlangung des Grades einesDoktors der Naturwissenschaftendes Fachbereiches Physikder Technischen Universit¨at Dortmundvorgelegt vonGiorgi PiranishviliAugust 2008AbstractThe goal of this research is the precise investigations of the processes which arehelpful to test the physics of the Standard Model and beyond it. We concentrateon the flavor sector of the theory which is still one of the sticking point in highenergy physics. At the same time flavor physics possesses a rich phenomenologywhich makes it one of the hot topics in the current theoretical and experimentalinvestigations.In this thesis we present the studies of several processes of particle physics takingplace at the energy scale of O(GeV), namely neutrino interactions with nucleonsand semileptonic B meson decays.For the neutrino scattering on nucleons with neutrino energies of about one GeV,we determine the form factors of the nucleon-resonance transition with the help ofthe recent electroproduction data. We extend the analysis to the second resonanceregion, where in addition to the resonanceP (1232), alsoD (1520),P (1440) and33 13 11S (1535) resonances contribute. Using the updated form factor fit we calculate the11differential and total cross sections for the resonance production by neutrinos.A detailed analysis of angular distributions is done for the exclusive decays B →∗¯K,K ll.

Sujets

• Physik

Informations

• Publié par: technischen_universitat_dortmund
• Publié le: 01 janvier 2008
• Nombre de lectures: 8
• Langue: English
• Poids de l'ouvrage: 1 Mo

Extrait

FlavorPhysics:
NeutrinoproductionofResonances
andSemileptonicB!K,Kl¯l
Decays

Dissertation

zurErlangungdesGradeseines

DoktorsderNaturwissenschaften

desFachbereichesPhysik

derTechnischenUniversit¨atDortmund

vorgelegtvon

GiorgiPiranishvili

August2008

Abstract

Thegoalofthisresearchisthepreciseinvestigationsoftheprocesseswhichare
helpfultotestthephysicsoftheStandardModelandbeyondit.Weconcentrate
ontheavorsectorofthetheorywhichisstilloneofthestickingpointinhigh
energyphysics.Atthesametimeavorphysicspossessesarichphenomenology
whichmakesitoneofthehottopicsinthecurrenttheoreticalandexperimental
investigations.
Inthisthesiswepresentthestudiesofseveralprocessesofparticlephysicstaking
placeattheenergyscaleofO(GeV),namelyneutrinointeractionswithnucleons
andsemileptonicBmesondecays.
FortheneutrinoscatteringonnucleonswithneutrinoenergiesofaboutoneGeV,
wedeterminetheformfactorsofthenucleon-resonancetransitionwiththehelpof
therecentelectroproductiondata.Weextendtheanalysistothesecondresonance
region,whereinadditiontotheresonanceP33(1232),alsoD13(1520),P11(1440)and
S11(1535)resonancescontribute.Usingtheupdatedformfactortwecalculatethe
dierentialandtotalcrosssectionsfortheresonanceproductionbyneutrinos.
AdetailedanalysisofangulardistributionsisdonefortheexclusivedecaysB!
K,Kl¯l.ThecalculationsareperformedinthelargerecoilregionusingtheQCD
factorizationformalism.WegivetheStandardModelpredictionsforthecoecients
ofangulardistributionofB!Kl¯ldecays,namelyFHlandAlFB.Thepredicted
valuesareremarkablefortheirvanishingvaluesintheStandardModelandsmall
theoreticaluncertainties.ThesensitivityofthesecoecientstoNewPhysicsis
studiedinamodel-independentway.
InthecaseofthedecayB!K(!K)l¯lweinvestigateeightCPasymmetries
intheStandardModelandBeyond.ThreeofthemareT-oddandveT-evenCP
asymmetries.IntheStandardModel,wheretheCPviolationcomesfromtheCKM
matrix,wepredictthevaluesoftheCPasymmetriestobeofO(103).Wealsoshow
thatthecurrentexperimentalboundsallowtheT-oddasymmetriestobeofO(1),
whereasthevaluesoftheT-evenasymmetriescanbeofO(0.1)inthepresenceof
NewPhysics.

Zusammenfassung

IndieserArbeitpra¨sentierenwirdieStudieneinigerausgewa¨hlterProzesseder
Teilchenphysik,dieanderEnergieskalavonO(GeV)stattnden,erstensdieWech-
selwirkungzwischenNeutrinosundNukleonenundzweitenssemileptonischeZerfa¨lle
derB-Mesonen.
ImFallederStreuungvonNeutrinosanNukleonenimEnergiebereichvonca.1
GeV,bestimmenwirdieFormfaktorenderNukleon-Resonanz-U¨berga¨ngemitHilfe
neuesterElektron-NukleonStreuungs-Daten.UnsereAnalysebeinhaltetaußerder
P33(1232)ResonanzauchdieD13(1520),P11(1440),S11(1535)Resonanzen.Unter
VerwendungdieseraktualisiertenFormfaktorenberechnenwirdendierentiellen
undgesamtenWirkungsquerschnittfu¨rdieErzeugungvonResonanzeninderNeu-
trino-NukleonStreuung.
ImFalledersemileptonischenB-Mesonzerfa¨llewerdenWinkelverteilungendesSpek-
trumsfu¨rdieexklusivenZerfa¨lleB!K,Kl¯ldetailliertdiskutiert.DieRechnung
beschra¨nktsichaufkleineinvarianteMassendesDileptonsystemesimRahmendes
FormalismusderQCDFaktorisierung.WirbestimmendieStandardmodellVorher-
sagederKoezientenderWinkelverteilungFHlundAlFBdesZerfallesB!Kl¯l.
DieseObservablenzeichnensichdurchihreverschwindendkleinenStandardmodell-
werteundkleinenUnsicherheitenaus.DesweiterenwirddieSensitivita¨tdieserKo-
ezientenaufSignaleNeuerPhysikinmodellunabha¨ngigerArtundWeisestudiert.
Fu¨rdieZerfa¨lleB!K(!K)l¯luntersuchenwirachtCPAsymmetrienimStan-
dardmodellunddaru¨berhinaus.DreivonihnensindT-ungeradeundfu¨nfT-gerade
CPAsymmetrien.ImStandardmodellistdieUrsachederCPVerletzungdieCKM
MatrixunddieCPAsymmetrienverschwindendkleinimBereichO(103).Wir
zeigenaußerdem,dassdiegegenwa¨rtigenexperimentellenDatenkeinewesentlichen
Einschra¨nkungendarstellenundfolglichdieT-ungeradenAsymmetrienimFalle
NeuerPhysikimBereichO(1)seinko¨nnen.DieSensitivita¨tderT-geradenAsym-
metrienaufSignaleNeuerPhysikistetwaskleiner,dieseko¨nnenimBereichO(0.1)
liegen.

Contents

1Basics1
1.1FlavorintheStandardModel......................1
1.2FromQuarkstoHadrons.........................4
1.2.1QCDLagrangian.........................4
1.2.2QuarkModelofHadrons.....................7
1.2.3FlavorSymmetries:IsospinandSU(3).............8
1.2.4HeavyQuarkSymmetry.....................12
1.3EectiveTheoryofElectroweakProcesses...............13
1.3.1Idea................................13
1.3.2HadronicMatrixElements....................15

2ResonanceProductionbyNeutrinos17
2.1Introduction................................17
2.2FormalismofResonanceProductioninNeutrino-NucleonInteractions19
2.2.1CrossSection...........................19
2.2.2HadronicMatrixElement....................20
2.3DeterminationofHelicityAmplitudesinElectroproduction......22
2.4CalculationoftheAmplitudes......................23
D13D13D13
2.4.1A,AandS.......................24
3/21/21/2
2.4.2HelicityAmplitudesfortheP(1232)Resonance.......26
332.4.3HelicityAmplitudesfortheP(1440)Resonance.......26
112.4.4HelicityAmplitudesfortheS(1535)Resonance........27
112.5DataAnalysisandtheExtractionsoftheFormFactors........28
2.5.1D(1520).............................29
312.5.2P(1232).............................30
332.5.3P(1440).............................30
112.5.4S(1535).............................31
112.6DecaysoftheResonancesandPCAC..................32
2.6.1P(1232).............................34
332.6.2D(1520).............................35
312.6.3P(1440).............................36
11

i

2.6.4S(1535).............................36
112.7CrossSectionsintheSecondResonanceRegion............37
2.8Conclusions................................39
¯3AngularAnalysisofB!K,KllDecays41
3.1Introduction................................41
¯3.2EectiveHamiltonianforb!sll....................42
3.3SomeNewPhysicsModels........................46
3.3.1MSSMwithLargetan.....................46
3.3.2ModelswithBrokenR-parity..................48
3.3.3Leptoquarks............................50
3.4FormFactorsandLargeRecoilLimit..................53
3.5StandardModelAnalysis........................57
¯3.5.1AngularDistributioninB!Kll................58
¯3.5.2AngularDistributioninB!K(!K)ll...........65
3.6NewPhysicsAnalysis...........................78
3.6.1ExperimentalConstraints....................79
¯3.6.2B!Kll:BeyondtheStandardModel.............87
3.6.3CPAsymmetriesinthePresenceofNewPhysics.......97
3.7Conclusion.................................102

4Summary

501

AResonanceProductionbyNeutrinos107
A.1StructureofHadronicTensorforP33andD13.............107
A.2StructureoftheHadronicTensorforP11andS11...........109
BAngularAnalysisofB!K,Kl¯lDecays111
B.1AngularCoecientsJi(a).........................111
B.2OptimalObservablesfromOptimalWeights..............112
B.3CPAsymmetriesandAFBbeyondtheSM...............112
B.4TaAmplitudes...............................114
B.5Model-independentCPAsymmetriesbeyondtheSM.........119

Bibliography

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Introduction

Thedevelopmentsofthelast50yearsinparticlephysicsgivethehopethatthe
descriptionofthenaturecanbearrangedintermsofseveralfundamentalprinciples.
TheStandardModel(SM)[1,2,3],themodeldescribingelectromagnetic,weakand
stronginteractions,issuchanattempt.Withthehelpofthequantumeldtheory
andtheprincipleoflocalgaugeinvariancetheSMexplainssuccessfullythewide
rangeofparticlephysicsphenomenauptodistancesofO(1018m),whichhasbeen
conrmedbyalargenumberofacceleratorexperiments.
InspiteofitssuccessonebelievesthattheSMisnotcomplete.Thereasonisa
numberofunansweredquestionsraisedinthetheory.Namely,thereisanumberof
parametersinthetheorywhosevaluesareunnaturallyremotefromeachother,more
thanonewouldexpect.Forexample,thereisalargedierence,aboutseventeen
ordersofmagnitude,betweentheelectroweakscaleandthePlanckscale.Similarly,
itisunclearwhythespectrumofmatterparticlesintheSMissodierent.The
massofthetopquarkexceedsthemassofoneoftheneutrinosbyelevenorders
ofmagnitude.Thisproblemisprobablycorrelatedwiththequestion:”Wheredo
massesoftheparticlescomefrom?”.Wealsodonotknowwhythereareonlythree
generationsofparticles.Although,thedirectexperimentalconstraintsstilldonot
ruleoutanadditionalfourthgeneration[4,5].TheneutrinosaremasslessintheSM,
whereastheoscillationexperimentsconrmedthatneutrinoshavemasses.Another
problemisrelatedtothefactthatourUniverseisobservedtohaveanexcessof
matteroverantimatter.Itwouldbeimpossibletoachieveitwithouttheexistence
ofCPviolatingprocessesduringtheevolutionoftheUniverse[6].Thus,itgenerates
theneedtohaveCPviolationinthetheory.Unfortunately,theamountofCP
violationintheSMisnotenoughtoexplainquantitativelytheasymmetrybetween
matterandantimatter.Thus,theseshortcomingsandinconsistenciesmotivateus
tothinkabouttheexistenceofphysicsbeyondtheSM,i.e.,NewPhysics(NP).We
hopethatthededicatedexperimentsattheLargeHadronCollider(LHC)willshed
lightonsomeofthesequestions.
Themostpartofthismanuscriptisdevotedtovariousphenomenologicalaspects
ofavorphysics.IntheSMthematterparticles(fermions)appearinthreegen-
erations.Flavorphysicsdescribestheinteractionsresponsibleforthetransitions
betweendierentgenerations.Therearetwosec