r-parity violation at dØ. run i results and run ii prospects
DESCRIPTION
PHENO 2002 SYMPOSIUM. R-parity violation at DØ. Run I results and Run II prospects. On behalf of the DØ collaboration Auguste Besson (ISN-Grenoble, France). R-parity violation at DØ. The TeVatron and the DØ detector R-parity violating SUSY (RPV) Pair production and RPV decays of LSP - PowerPoint PPT PresentationTRANSCRIPT
Pheno 2002 Symposium, Madison, April 22-24 2002 Auguste Besson 1
R-parity violation at DØ.R-parity violation at DØ.Run I results and Run II Run I results and Run II
prospectsprospects
R-parity violation at DØ.R-parity violation at DØ.Run I results and Run II Run I results and Run II
prospectsprospects
On behalf of the DØ collaborationOn behalf of the DØ collaboration
Auguste BessonAuguste Besson(ISN-Grenoble, France)(ISN-Grenoble, France)
PHENO 2002 SYMPOSIUM
Pheno 2002 Symposium, Madison, April 22-24 2002 Auguste Besson 2
R-parity violation at DØR-parity violation at DØR-parity violation at DØR-parity violation at DØ• The TeVatron and the DØ detectorThe TeVatron and the DØ detector• R-parity violating SUSY (RPV)R-parity violating SUSY (RPV)• Pair production and RPV decays of Pair production and RPV decays of
LSPLSP and ’ couplings
• Resonant sparticle productionResonant sparticle production ’ and ’’ couplings
• Top decay via RPVTop decay via RPV ’ and ’’ couplings
• Conclusion and outlookConclusion and outlook
Pheno 2002 Symposium, Madison, April 22-24 2002 Auguste Besson 3
The TeVatronThe TeVatronThe TeVatronThe TeVatron• Run II started March 2001Run II started March 2001• Increased LuminosityIncreased Luminosity
– Main injector, RecyclerMain injector, Recycler– # bunches, # antiprotons# bunches, # antiprotons
• Increased EnergyIncreased Energy– 1.8 to 1.96 TeV1.8 to 1.96 TeV
CDF DØ
MI. + Recycler
TeVatron
2.32.32.52.5
13213239639635003500
~ 15~ 15~ 2~ 2~ 0.13~ 0.13
5.2x105.2x1032328.6x108.6x1031311.6x101.6x103030
1.961.961.961.961.81.8
140 x 103140 x 10336 x 3636 x 366 x 66 x 6
Run 2bRun 2bRun 2aRun 2aRun 1bRun 1b
4.84.8interactions/xinginteractions/xing
bunch xing (ns)bunch xing (ns)
Ldt (fbLdt (fb-1-1))
typ L (cmtyp L (cm-2-2ss-1-1))
s (TeV)s (TeV)
#bunches#bunches
Pheno 2002 Symposium, Madison, April 22-24 2002 Auguste Besson 4
Run IIa current LuminosityRun IIa current LuminosityRun IIa current LuminosityRun IIa current Luminosity
• typical Luminositytypical Luminosity ~ 10~ 103131 cm cm-2-2ss-1-1
• Integrated LIntegrated L ~ 36 pb~ 36 pb-1-1 delivered delivered
Pheno 2002 Symposium, Madison, April 22-24 2002 Auguste Besson 5
The DØ upgradeThe DØ upgradeThe DØ upgradeThe DØ upgrade• Run IRun I- excellent calorimetryexcellent calorimetry
LAr/U, hermetic, compensationLAr/U, hermetic, compensation
• Run II upgradeRun II upgrade- New trackingNew tracking
Silicon trackerSilicon tracker
Fiber trackerFiber tracker- Central solenoid Central solenoid
2 Teslas2 Teslas
- Preshower- Preshower
- Forward muon system- Forward muon system
- Electronics- Electronics
- Triggers- Triggers
Pheno 2002 Symposium, Madison, April 22-24 2002 Auguste Besson 6
• SUSY SUSY - New symmetry between fermions and - New symmetry between fermions and bosonsbosons- Solves hierarchy problem- Solves hierarchy problem- allows convergence of coupling - allows convergence of coupling constants at GUT scaleconstants at GUT scale- complete new spectrum of susy - complete new spectrum of susy particlesparticles..
• In most of the modelsIn most of the models- SUSY particles are pair produced- SUSY particles are pair produced
- The lightest SUSY particle (LSP) is - The lightest SUSY particle (LSP) is stable and escape from detector.stable and escape from detector.
SupersymmetrySupersymmetrySupersymmetrySupersymmetry
llgggqqqpp jijiji
~~,~~,~~,~~,~~,~~,~~ 000
BosonFermionQFermionBosonQ ||;||
Pheno 2002 Symposium, Madison, April 22-24 2002 Auguste Besson 7
• SUSY potential: SUSY potential:
i,j,k = 1,2,3i,j,k = 1,2,3 (family indices)(family indices) 9 + 27 + 99 + 27 + 9 = 45 new Yukawa couplings. = 45 new Yukawa couplings. Lepton (Lepton ( and and ’) or Baryon (’) or Baryon (’’) ’’)
number number not conservednot conserved define R-parity : define R-parity : discrete quantum numberdiscrete quantum number
B= Baryon nb, L=nb Lepton B= Baryon nb, L=nb Lepton nb, S=spinnb, S=spin
RRpp= +1 = +1 SM particle SM particle
RRpp= -1 = -1 SUSY particle SUSY particle
not excluded theoriticallynot excluded theoritically
R-parityR-parityR-parityR-parityWWW RpVMSSMSUSY
kjikjikjiijkRpV DDUDQLELLW ijkijk
''' WithWith
Rp = (-1)3B+2S+L
Pheno 2002 Symposium, Madison, April 22-24 2002 Auguste Besson 8
R-parity violating : R-parity violating : consequencesconsequences
R-parity violating : R-parity violating : consequencesconsequences
• The Lightest Susy Particle (LSP) decays The Lightest Susy Particle (LSP) decays eithereither- inside the detector - inside the detector (with or without a displaced (with or without a displaced
vertex)vertex)
- outside the detector outside the detector (similar to Rp conserved (similar to Rp conserved analysis) analysis)
• Susy signature can be very differentSusy signature can be very different– Less missing EtLess missing Et– More leptons (More leptons ( or or ’) and jets (’) and jets (’ or ’ or ’’)’’)
• Single Susy particle production is possibleSingle Susy particle production is possible- via via ’ or ’ or ’’ @ TeVatron’’ @ TeVatron
• LSP is not anymore a candidate for dark LSP is not anymore a candidate for dark mattermatter
kd
ju
il~
~
i'ijk
(+1)
(+1) (+1)
(-1)
Pheno 2002 Symposium, Madison, April 22-24 2002 Auguste Besson 9
RPV Experimental RPV Experimental constraintsconstraints
RPV Experimental RPV Experimental constraintsconstraints
• Indirect limits via low energy processesIndirect limits via low energy processes- e-e--- universality - Neutrinoless double-beta decay universality - Neutrinoless double-beta decay
- Charged current universality - Top decay- Charged current universality - Top decay
- Atomic parity violation - etc.- Atomic parity violation - etc.
• 22 limits for m = 100 GeV limits for m = 100 GeV (limits often linear in mass)(limits often linear in mass)
• Stronger limitsStronger limits
on products on products
of couplingof coupling
-- proton decay :proton decay :
’’’’11k 11k . . ’’11k11k < 10 < 10-22-22
Barger et al. Phys.Rev. D40 (89)Ledroit, Sajot GDR-S-008 (98)Allanach et al., PRD 60 (99)
~~
u
ud
u
ddkk
~~
d_e+
pp
Pheno 2002 Symposium, Madison, April 22-24 2002 Auguste Besson 10
RPV search at DØ : hypothesisRPV search at DØ : hypothesisRPV search at DØ : hypothesisRPV search at DØ : hypothesis
• mSUGRA framework mSUGRA framework (m(m00 ; m ; m1/21/2 ; A ; A00 ; sign ; sign ; tan ; tan ))
• LSPLSP• Only one Yukawa coupling Only one Yukawa coupling
((ijkijk,,’’ijkijk,,’’’’ijkijk) ) dominatesdominates
• Pair productionPair production
all pair production included, all pair production included,
then 2 LSP decay via RPV.then 2 LSP decay via RPV.• If RPV coupling is largeIf RPV coupling is large
resonant production is possibleresonant production is possible
01
~
Pheno 2002 Symposium, Madison, April 22-24 2002 Auguste Besson 11
• 2 susy particles produced 2 susy particles produced 2 LSP 2 LSP• Dominant coupling Dominant coupling ’’1jk 1jk (j=1,2 ; k=1,2,3)(j=1,2 ; k=1,2,3)• If LSP decays inside the detector:If LSP decays inside the detector:
coupling not to small,coupling not to small, ((’’1jk1jk >~ 10 >~ 10-3-3))LSP LSP 1 e + 2 jets 1 e + 2 jets
• Background: Background: Drell-Yan, tt,Drell-Yan, tt,
ZZee++ee- - + jets, misidentification of jets as electrons+ jets, misidentification of jets as electrons
• Cuts: Cuts: pTel pTel 15 & 10 GeV; pTjet 15 & 10 GeV; pTjet 15 GeV; Mee 15 GeV; Mee 76-106 GeV 76-106 GeV
Pair production: dielectron Pair production: dielectron channelchannelPair production: dielectron Pair production: dielectron channelchannel
Final State : 2 electrons + 4 jetsFinal State : 2 electrons + 4 jets
__
__
01
~e~
e
c
s
'122
Pheno 2002 Symposium, Madison, April 22-24 2002 Auguste Besson 12
Dielectron channel : mDielectron channel : m00-m-m1/21/2 plane planeDielectron channel : mDielectron channel : m00-m-m1/21/2 plane plane• Run I results :Run I results : L = 99 pbL = 99 pb-1 -1 , , s = 1.8 TeVs = 1.8 TeV
- Expected Backgd : - Expected Backgd :
1.8 1.8 0.2 0.2 0.3 0.3
- Events observed : - Events observed : 22
• Run II : Run II : L = 2fbL = 2fb-1-1, , s = 2 TeVs = 2 TeV
- Scenario I Scenario I Extrapolation from Run IExtrapolation from Run I
- Scenario IIScenario II upgraded detectorupgraded detector
AA00 = 0 ; = 0 ; < 0 ; tan < 0 ; tan = 2 = 2
Run II : Allanach et al. hep-ph/9906224
mg ~ 550 GeVmg ~ 550 GeVmq ~ 500 GeVmq ~ 500 GeV
~~~~
D0, Phys. Rev. Lett. 83, 4476 (99)
Pheno 2002 Symposium, Madison, April 22-24 2002 Auguste Besson 13
Pair production: dimuon channelPair production: dimuon channelPair production: dimuon channelPair production: dimuon channel
• Similar analysisSimilar analysis
• Dominant coupling Dominant coupling ’’2jk2jk
• Backgd : Backgd : Drell-Yan, tt, ZDrell-Yan, tt, Z+jets, Z+jets, Z,WW,WW + + jetsjets
• Cuts : Cuts : pTpT > 15 & 10 GeV, pT > 15 & 10 GeV, pTjetsjets > 15 GeV, > 15 GeV,
Scalar ET > 150 GeV, MScalar ET > 150 GeV, M>5GeV, Acoplanarity > 0.03>5GeV, Acoplanarity > 0.03
• Run I : Run I : L = 77.5 L = 77.5 4 pb 4 pb-1-1
Events observed = 0Events observed = 0
Expected Background = 0.18 Expected Background = 0.18 0.03 0.03 0.02 0.02
Final State : 2 muons + 4 jetsFinal State : 2 muons + 4 jets
01
~~
c
s
'222
Pheno 2002 Symposium, Madison, April 22-24 2002 Auguste Besson 14
dimuon channel : mdimuon channel : m00-m-m1/21/2 plane planedimuon channel : mdimuon channel : m00-m-m1/21/2 plane plane
AA00 = 0 ; = 0 ; < 0 ; tan < 0 ; tan = 2 = 2Run IRun I Run IIRun II (2fb-1)
D0, hep-ex/0111053 Submitted to PRL.
Pheno 2002 Symposium, Madison, April 22-24 2002 Auguste Besson 15
• Dominant coupling Dominant coupling 121121, , 122 122 oror 233233
LSP LSP 2 charged leptons + 1 2 charged leptons + 1
• Backgd: Backgd: Drell-Yan, tt, ZDrell-Yan, tt, Z,,
misidentification of jets as electronsmisidentification of jets as electrons
• Run I :Run I :
Pair production: multileptons channelPair production: multileptons channelPair production: multileptons channelPair production: multileptons channel
D0, PRL 80, 1592 (1998)D0, Phys. Rev. D Rapid. Comm. 62, 071701 (2000)
Final State : Final State : eee,ee eee,ee,e,e,, + missing ET + missing ET
e01
~e
~
e121
eee ee e
L (pb-1) 97.85.2 97.85.2 93.14.9 78.34.1
Evts 0 0 0 0
Bkgd 0.340.07
0.610.36
0.110.04 0.200.04
Pheno 2002 Symposium, Madison, April 22-24 2002 Auguste Besson 16
multileptons channel : mmultileptons channel : m00-m-m1/21/2 planeplane
multileptons channel : mmultileptons channel : m00-m-m1/21/2 planeplane
• Contours :Contours :121121, , 122 122 oror
233233
< 0 or > 0 < 0 or > 0
tan tan = 5, 10 = 5, 10
Pheno 2002 Symposium, Madison, April 22-24 2002 Auguste Besson 17
mme1e2e3e1e2e3 = 85.2 = 85.2 GeV/cGeV/c22 MEMETT =10.7 GeV =10.7 GeV
mme2e3e2e3 = 63.5 = 63.5mme1e3e1e3 = 10.8 = 10.8mme1e2e1e2 = 55.7 = 55.7
e3e3e2e2e1e1
EETT = = 13.2 GeV13.2 GeV
ppTT = 15.1 GeV = 15.1 GeV
= = 1.1.0606
= = 5.725.72
ChargeCharge = -1= -1
EETT = = 13.9 GeV13.9 GeV
ppT T = = 10.9 GeV10.9 GeV
= = --1.941.94
= = 2.802.80
ChargeCharge = +1= +1
EETT = = 17.9 GeV17.9 GeV
ppTT = = 0.52 GeV0.52 GeV
= 0.43= 0.43
= 5.42= 5.42
ChargeCharge = +1= +1
D Run 2 Preliminary
Electrons
Trilepton eventsare classical
SUSY signatureElectron
eee candidate eventeee candidate eventeee candidate eventeee candidate event
Pheno 2002 Symposium, Madison, April 22-24 2002 Auguste Besson 18
MEMETT =31.8 GeV =31.8 GeV
mm = 41.5 GeV/c = 41.5 GeV/c22
2211ee
ppTT = = 9.9.82 GeV82 GeV
= = -1.48-1.48
= = 2.882.88
Charge = 1Charge = 1
ppTT = = 228.2 GeV8.2 GeV
= = -0.-0.1010
= = 6.206.20
Charge = -1Charge = -1
EETT = = 19.2 GeV19.2 GeV
= 0.40= 0.40
= 0.63= 0.63
No track matchNo track match
D Run 2 Preliminary
Muon
Electron
MET
Muon system
Muon
ee candidate event candidate eventee candidate event candidate event
Pheno 2002 Symposium, Madison, April 22-24 2002 Auguste Besson 19
Resonant production : dimuons Resonant production : dimuons channelchannel
Resonant production : dimuons Resonant production : dimuons channelchannel
• Dominant coupling Dominant coupling ’’211211
resonant prod via RPV resonant prod via RPV Decay of LSP via RPVDecay of LSP via RPV
• Backgd : Backgd : tt, Z+2jets, WW+jetstt, Z+2jets, WW+jets
• Cuts : Cuts : pTpT 20 GeV ; pT 20 GeV ; pTjets jets 20 GeV 20 GeV
Scalar ET Scalar ET 50 GeV ; 50 GeV ; RRjets jets 0.5 0.5
u 1o~
L
~
d_
u d
'211
Final State : Final State : 2 2 + 2 jets + 2 jets
u d
d 1-~
+
~
d_
l -
l
W -
1o~
_
_
Pheno 2002 Symposium, Madison, April 22-24 2002 Auguste Besson 20
Dimuons in mDimuons in m00-m-m1/21/2 planeplane
Dimuons in mDimuons in m00-m-m1/21/2 planeplane
• Run I: Run I: L = 94 L = 94 5 pb 5 pb-1-1
Events observed = 5Events observed = 5
Expected Background = 5.34 Expected Background = 5.34 0.07 0.07
AA00 = 0 ; = 0 ; < 0 ; tan < 0 ; tan = 1.5 = 1.5
95% conf. level95% conf. level
• Run II: Run II: (Fast (Fast simulation)simulation) ’’211211=0.05=0.05
preliminarypreliminary
Déliot et al., EPJ C 19 (01) 155
AA00 = 0 ; = 0 ; < 0 ; tan < 0 ; tan = 2 = 2
Pheno 2002 Symposium, Madison, April 22-24 2002 Auguste Besson 21
Resonant production : 3 leptons Resonant production : 3 leptons channelchannel
Resonant production : 3 leptons Resonant production : 3 leptons channelchannel
u d
d 1-~
+
~
d_
l -
l
W -
1o~
Déliot et al., EPJ C 19 (01) 155AA00 = 0 ; = 0 ; < 0 ; tan < 0 ; tan = 1.5 = 1.5
Final State : 3 Final State : 3 + 2 jets + 2 jets
Mass reconstructionMass reconstruction
Fast simulation: M̃01=77.7 GeV (MC input)
2 jets and softer muon: M̃01=71 GeV (9)
LLintint = 10fb = 10fb-1-1
’’211 211 = 0.09= 0.09
Pheno 2002 Symposium, Madison, April 22-24 2002 Auguste Besson 22
• Dominant coupling Dominant coupling ’’’’3jk3jk
Resonant stop productionResonant stop production
Stop decays to b Stop decays to b
to which decays outside the detectorto which decays outside the detector
• Backgd:Backgd:W+b-fake,Wbb,Wcc, single topW+b-fake,Wbb,Wcc, single top
• Cuts: Cuts: pTb > 40 GeV ;pTb > 40 GeV ;
pTlepton > 20 GeV;no other lepton or jetpTlepton > 20 GeV;no other lepton or jet
• Run I: 110 pbRun I: 110 pb-1-1
Resonant Squark Resonant Squark ProductionProduction
Resonant Squark Resonant Squark ProductionProduction
1
~
1~ 0
1~
d 1+~
b
t~
s''
3jk
l
l
W
1o~
Berger et al.,PRD 63, 115001 (01)
Final State : 1 charged lepton, 1 b-jet + missing ETFinal State : 1 charged lepton, 1 b-jet + missing ET
Pheno 2002 Symposium, Madison, April 22-24 2002 Auguste Besson 23
• Run II studies : Run II studies : ’’’’3jk3jk , 2 fb , 2 fb-1-1
– Perspectives with Fast simulation Perspectives with Fast simulation (SHW)(SHW)
Resonant Squark Resonant Squark ProductionProduction
Resonant Squark Resonant Squark ProductionProduction
Berger et al.,PRD 63, 115001 (01)
Pheno 2002 Symposium, Madison, April 22-24 2002 Auguste Besson 24
150 160 170 180 190 Sbottom Mass (GeV)
5.00
2.00
1.00
0.50
0.20
0.10
0.05
’’ 3
31
’’’’331 331 dominant couplingdominant coupling• tt production tt production t t bdbd
t t WW--b b llbb• decays outside the detectordecays outside the detector
• Backgd : Backgd : tt, Wbbjtt, Wbbj• Cuts : Cuts : pT> 20 GeV, |pT> 20 GeV, || < 2.5,| < 2.5, Rjj > 0.5Rjj > 0.5
• Run II studiesRun II studies
(fast simulation, 2fb(fast simulation, 2fb-1-1))
+ + ’’’’333 333 studiesstudies
Top decay via RPV : Run II Top decay via RPV : Run II studiesstudies
Top decay via RPV : Run II Top decay via RPV : Run II studiesstudies
Final state: 1 lepton + 2 b-jets + 1 jet + ETmissFinal state: 1 lepton + 2 b-jets + 1 jet + ETmiss
01
~__
__
01
~
''331t
bd
b~
01
~
Abraham et al. Phys.Lett.B 514 72 (2001) Abraham et al. Phys.Lett.B 514 72 (2001) Eilam et al. Eilam et al. Phys.Lett.BPhys.Lett.B 510510 227227 ( (20012001))
__ __
Han et al. Phys. Lett.B 476 79 (2000)Han et al. Phys. Lett.B 476 79 (2000)
__
Pheno 2002 Symposium, Madison, April 22-24 2002 Auguste Besson 25
ConclusionConclusionConclusionConclusion• RUN I : RUN I : many channels and couplings many channels and couplings
exploredexplored
• RUN IIa : RUN IIa : – improved detector ; Limproved detector ; Lintint10 ; 10% more 10 ; 10% more
energyenergy– DØ is already taking data.DØ is already taking data.
~ 300 pb~ 300 pb-1-1 expected at the end of 2002. expected at the end of 2002.
~ 2 fb~ 2 fb-1-1 in 2004. in 2004.– Great discovery potential both in pair/single Great discovery potential both in pair/single
production.production.
No RPV signal foundNo RPV signal found
Pheno 2002 Symposium, Madison, April 22-24 2002 Auguste Besson 26
Feynman diagramsFeynman diagramsFeynman diagramsFeynman diagrams
• Via Via ’’122122
01
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e
cs
'122
122'
ev~
s
sc~
e
ss~
e
s
e~c
ss~
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