Embed Size (px)
Citation preview
ElectroweakandBSMphysicsatanEICYuxiangZhao
POETIC7@TempleUniversity
1
Abhay Deshpande,KrishnaKumar,SeamusRiordan(SBU)Jin Huang(BNL)
Outline•IntroductionofElectroweakinteractions•ElectroweakphysicsatanEICqNucleonspinstructureqTheweakmixinganglesin2Өw
•ChargedLeptonFlavorViolation(CLFV)studyatanEIC
•Summary2
Chen-Ning YangTsung-Dao Lee
Chien-Shiung Wu
Symmetries play a central role in physics. Parity, Time Reversal, Charge Conjugation, …, were naturally assumed to be conserved until
T.D. Lee and C.N. Yang first suggested parity violation. Awarded Nobel Prize 1957 after experimental confirmation.
"for their penetrating investigation of the so-called parity laws which has led to important discoveries regarding the elementary particles"
DiscoveryofParityViolation
C. S. Wu led the experiment confirmed parity violation in nuclear β-decay
Glashow-Weinberg-Salam (GWS) theory yields the unification of electroweak interaction and predicts Z boson 3
Electro-weakinteractions
4
Spin-1/2particlescarrytwotypesofcouplings:AxialandVectorAxial:differenceofstrengthforleft/righthandedstatesVector:Averageofthetwo
Nodifferenceforleft/rightparticleVectorcoupling=Q
Onlyinteractwithleft-handedfermions
Interactwithbothleftandrighthandedfermions
ParityViolatingElectronScattering--- Neutralcurrent
5
NoPV YesPV
TodetectPV:long.pol.Electron+unpol.Nucl.
IncontextofSMTreelevel…
ParityViolatingElectronScattering--- Neutralcurrent
6
NoPV YesPV
IncontextofSMTreelevel…
TodetectPV:long.pol.Electron+unpol.Nucl.
SpinstructurestudyBeforeEIC---StructurefunctionsandPDFsine-p(n)DISprocesses
7
Experimental observables PDFs
Unpolarized structure functions
F1ү F2
ү
Unpolarized cross section
ALL ALT
Polarized structure functions
g1ү g2
ү
Unpolarized pdfs:f(x)=q↑(x) + q↓(x)
Quark-Parton ModelQPM
Polarized pdfs:Helicity distribution ∆q=q↑(x) - q↓(x)
No g2 interpretation in QPM
~50%
~30%Spin crisis
SIDIStoaccessTMDs,DVCStoaccessGPDs…3Dera…ongoingefforts
FlavorDecompositions--- anexampleforpolarizedcase
• Withpureү exchangeininclusiveDIS:
• Assumption:SU(3)flavorsymmetry
Δu+Δd-2 Δsü Additionalinputsfromβ-decayofneutronandhyperons
ü SIDISmeasurementsalsoprovidesomeinformation,fragmentationprocessisinvolved
8
Hmm…Nothirdkindofnucleon…
Δu+Δd
ElectroweakinteractionsinDISregionatanEICcanhavenewinputs…
EICoffersnewopportunitieswithweakneutralcurrents
9
Anselmino,Efremov,Leader,Ji…Phys.Rep.216(1995)
pol.electron&unpol.nucleon:
WithparityviolationandQ2 <<Z2
unpol.electron&pol.nucleon:
Inclusiveelectronmeasurements
Newstructurefunctions---ү-Zinterferencestructurefunctions
10
pol.electron&unpol.nucleon: unpol.electron&pol.nucleon:
NewanduniquecombinationsofindividualPDFs
Newstructurefunctions---ү-Zinterferencestructurefunctions
11
pol.electron&unpol.nucleon: unpol.electron&pol.nucleon:
WexchangeinDISregion
12
Parity-violatingasymmetriesine-Dcollisions
13
§ Deuteronhassameamountofuanddinx>0.2region§ APV~20/3sin2Өw -1§ FundamentalquantityinSM,constraintsonnewphysics,suchasnewZbosonetc.
1loopcalculationCzarneckl andMarciano
Parity-violatingasymmetriesine-Dcollisions
14
§ Deuteronhassameamountofuanddinx>0.2region§ APV~20/3sin2Өw -1§ FundamentalquantityinSM,constraintsonnewphysics,suchasnewZbosonetc.
Simulations• DJANGOHgeneratorsimulatesDISprocessesincludingQEDandQCDradiationüDevelopedbyHubertSpiesberger andusedatBNLfortheEICChargedCurrentstudy
• Electron-protoncollisionstostudynewstructurefunctionsüThedataisbinnedin(x,Q2)twodimensionsüDoingYdependentfittoextractprojectionsonF1үZ ,F3үZ ,g1үZ ,g5үZ
• sin2Өw projectionsarefromelectronbeamasymmetriesine-Dcollisions• Highlightsoftheprojections:
ü Cuts:q Q2>1GeV2,Wh>2GeV,y>0.1,pcutforstructurefunctionstudiesq Q2<6400GeV2 andx>0.2inadditionforsin2Өw projections
ü Unfoldingforkinematicalmigrationduetoradiationandfinitedetectorresolution 15
16
ePHENIX
PleaserefertoePHENIX LOIforthedetails
Detectorsmearing
17
Reference[2] Reference[1]
Tracking
EMCal:
e-p collisions 10x100,10x250,15x100,15x250
Runtimeluminosity 1034 /cm2/s
Detector efficiency 70%
Beam efficiency 70%
Beam timeforrunning 2.5 years5monthsperyear=12.5months
luminosityafterallefficiencies 40 fb-1 permonth
Integratedluminosity 500fb-1Proton(electron)beampolarization 70%(80%)
Uncertaintyofproton(electron)beampolarization 5%(2%)
18
Luminosityandpolarizationtable(e-pcollisions)
e-D collisions 10x100,10x250,15x100,15x250,20x250
Runtimeluminosity(pernucleon) 1034 /cm2/s
Detector efficiency 70%
Beam efficiency 70%
Beam timeforrunning 200 days
luminosityafterallefficiencies 40fb-1 permonth
Integratedluminosity 267fb-1Electronbeampolarization 80%
Uncertainty ofelectronbeampolarization 2%19
Luminosityandpolarizationtable(e-Dcollisions)
•Unpolarized structurefunctionsqe-pcollisionsqelectron:longitudinallypolarizedqproton:unpolarizedqIntegratedluminosity:500fb-1
20
Predictedasymmetries
21
F1үZ dominatestheasymmetry
δA/Aasafunctionofx
22
δA(sys)/A<0.5%Diff.Lumi.Sys.~5x10-4
Unpol.SFsprojectionsafterunfolding
23
•Polarizedstructurefunctionsqe-pcollisionsqe:unpolarizedqp:longitudinallypolarizedqIntegratedluminosity:500fb-1
24
Predictedasymmetries
25
Predictedasymmetries
26
δA/Aasafunctionofx
27
δA(sys)/A<3%Diff.Lumi.Sys.~3x10-4
Pol.SFsprojectionsafterunfolding
28
•Weakmixingangleqe-Dcollisionsqe:longitudinallypolarizedqD:unpolarizedqIntegratedluminosity:267fb-1(200days)
29
δA/Afore-Dcollisions
30
Diff.Lumi.Sys.~5x10-4
• Achallengeforpolarimeter
• Polarimetry~1%atthebeginningandthen0.5%forhigherenergyandhigherluminosity
• R&Dproposal:targetat1%inthefirststage
Worlddataofsin2ӨwincludingEICprojections
31
• 200daysofdedicatedrun
• CanreachsimilarprecisiontoSoLID measurement
• InterestingQ2 regionneverbeenmeasuredorplanned
ChargedLeptonFlavorViolationatanEIC
32
LeptonFlavorViolation• Solidevidencesshowingthatneutrinoshavesmallbutnon-zeromasses• Neutrinooscillationswithlargemixingangles• LeptonFlavorViolationoccursinChargedLeptonstoo…
33
SUSYSM
Slepton-neutralino loops Chargino-sneutrino loops
BR(μàe)~10-15BR(μàe)<10-54
Neutrinooscillation
Canbeobservable…Extremelysmall… Atheoryreview:PRD77,113010(2008)
SearchforLeptonFlavorViolation• Majorexperimentalsearchesareongoing
üNeutrinoless conversionofstoppedmuonstoelectronsinnuclei(μ↔e)üRaredecayofafreemuontoanelectronandphoton(μ↔e)üRaredecayofakaontoanelectronandmuon(μ↔e)üTaudecaysate+e- colliders(τ↔e)
34
Needveryhighfluxesforrequiredstatisticalreach
Doableatnewhighintensitykaon&muonbeamsandhighluminositye+e- collidersallovertheworld
EICcanalsocontribute…EspeciallyafterpioneereffortsatHERA
LeptonFlavorViolationsearchatepcollider
35
e↔μ ore↔τ
Mediatedbyleptoquark containingbothLeptonandbaryonquantumnumbers
NullresultatHERAwithlumi.of410pb-1 assumingλ=0.3
LeptonFlavorViolationsearchatanEIC
36 1e-00
5
0.00
01
0.00
1
0.01 0.
1 1 10 100 11
12 13
21 22
23 31
32 33
Ratio: λi λj / MLQ2 (TeV-2)
(q i q j)
Lepto
-Quar
k: e q
i --> τ q
j
EIC- S
malles
t ratio
can e
xplor
eHE
RA - U
pper
exclu
sion l
imits
0.0001
0.001
0.01
0.1
1
10
100
10 100 1000 10000 100000
Rat
io: �
i �j /
MLQ
2 (TeV
-2)
Mass for (qi qj) generation (GeV)
Lepto-Quark: e qi --> � qjEIC- Smallest ratio can exploreHERA - Upper exclusion limits
10fb-1
Arecentstudy,JHEP11,045(2010),showedthattheupperlimit
on!"#!$%&'() byHERAcouldbeextendedby2ordersofmagnitudeatanEIC
Assuming100%efficiency
MCgeneratorlevelstudies….Sofar• Standardmodelbackgroundsgenerated:Neutral&ChargedcurrentDIS,photo-production,lepton-pairproduction&Wproduction….CompareeventtopologieswiththeLQevents
• t hasacleansignature:AnalysissimilartothoseperformedinH1andZEUSindicatesthatreliableidentificationofTauiscertainlypossiblebothforüLeptonic DecaysoftüHadronicDecays:Narrow“pencil”likejetswith1-3pions
• VerycleardifferencesintopologiesofSMandLQeventsestablished.GEANTdetectorsimulationsnowunderway… 37
Eventtopology
38
Topology:neutralcurrentDISevent;exceptthattheelectronisreplacedbytaulepton
• Ifforwardintheincidentelectrondirection,thetauwouldbeisolated• Ifmixedinwithhadronremnants,thetauwouldbeboosted• Potentialforcleanidentificationwithhighefficiency:
v lookforsinglepion,threepions inanarrowcone,singlemuon:shouldbeabletodeviseseveralgoodtriggers
vtauvertexdisplaced200to3000microns:wouldgreatlyhelpbackgroundrejectionandmaintainhighefficiencyifvertexdetectorisincludedinEICdetectordesign
JetsatGeneratorLevel(firstlook)
39
Analysis
Jets at generator level
Figure: Plot (a) Angular distribution of hadronic � decay products in LQ data.Plot (b) shows the corresponding distribution using leading charged pions thatwere not associated with the known � jet
Raghav Kunnawalkam Elayavalli (SBU) Beyond the Standard Model � jet at the EIC detector December 18th 2012 24 / 36
t decayjet Normalhadronic jetinDIS
DISJetwidthisabout2timestothet-jetwidth
Analysis
� Projection
(a) LQ, �� projection in the detector (b) DIS, �� projection in the detector
Figure: �� projection of the widths of the di⇥erent jets in the detector for similarnumber of events : Hits collected by the EM calorimeter
Raghav Kunnawalkam Elayavalli (SBU) Beyond the Standard Model � jet at the EIC detector December 18th 2012 26 / 36
40
Analysis
Jets in the Detector
Figure: Angular Distribution of the di�erent jets in the detector: Hits collected bythe EM calorimeter
Raghav Kunnawalkam Elayavalli (SBU) Beyond the Standard Model � jet at the EIC detector December 18th 2012 25 / 36
Analysis
Jets in the Detector
Figure: Angular Distribution of the di�erent jets in the detector: Hits collected bythe EM calorimeter
Raghav Kunnawalkam Elayavalli (SBU) Beyond the Standard Model � jet at the EIC detector December 18th 2012 25 / 36
t decayjet Normalhadronic jetinDIS
“pencil-like”jets,comparedto“hadronicjets”
VeryearlyG4simulationcoupledtoeventgeneratorη
φ
η
φ
Summary•Presentedtheprojectionsofnewunpol./pol.SFsqUniquecombinationsofPDFsqBrandnew,neverbeenmeasuredbeforeqIndependinputstotheworlddatafitwithhighprecision
•PresentedtheprojectionsofweakmixingangleqReachrelativehighprecisioninaninterestingQ2 regionqDedicated200daysofbeamtime
• Impactstudyonindividualunpol-pdfs/pol-pdfs areunderwaywithCJ-Collaboration/DSSVgroup
•CLFV: PotentialtodiscoverBSMphysicsatanEIC 41
Backups
42
Center-of-masstable
43
Beamenergyconfiguration(exp,GeV) CenterofMass (GeV)
10x100 63
10x250 100
15x100 77
15x250 122
20x250 141
Whatholds/glueshadronstogether
44
Spinstructure
Massstructure
12
=12�⌃ + LQ
�+ [�g + LG]
Weknowverylittle…
Nuclei
qaversatilerangeofkinematicsqbeampolarizationsqhighluminosityqdifferentbeamspecies
45
qpreciselyimagetheseaquarksandgluonsinnucleonsandnuclei
qexplorethenewQCDfrontierofstrongcolorfieldsinnuclei
qresolveoutstandingissuesinunderstandingnucleonsandnucleiintermsoffundamentalbuildingblocksofQCD
AnewlyproposedFacility,ElectronIonCollider
With TO
EIC:theworldwideinterests
46
Germany CERN US China Germany
Checkofdetectorsmearing---theta
Inputresolutionis10mrad
47
Checkofdetectorsmearing---phi
Inputresolutionis0.3mrad
48
Checkofdetectorsmearing---dp/p(for5+/- 0.1GeVparticles)
49
Parametrizeddetectionresolutionsforinclusiveelectrons
50
Projectionsonthemeasuredyield(beforeunfolding)
51
Projectionsonthemeasuredyield(beforeunfolding)
Duetothesignchangeofg1gzfunction
52
Projectionsonmeasuredyield
53
Projectionsconsideringbinmigration
54
10x250
20x325
55
Acoplanarity:Dfmiss-tjet
10x250
20x325
EventTopology:LQvsSMMissingPT
Flavordecompositions• Withpureү exchangeininclusiveDIS:
• Assumption:SU(3)flavorsymmetry
Δu+Δd-2 ΔsAdditionalinputsfromβ-decayofneutronandhyperons
Δ∑ =Δu+Δd+ΔsOnlytwocombinationsofΔu,Δd,Δs
Otherprocessescanalsocontribute,butwithadditionalsys.errorsandassumptions 56
Hmm…Nothirdkindofnucleon…
Δu+Δd
Δ∑ (p)=0.15Δ∑ (N)=0.35Schemedependent…
