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Search for Supersymmetry Using Rare B 0 s(d) Decays at CDF Run II Vyacheslav Krutelyov Department of Physics Texas A&M University HEP Seminar Dec 20, 2005 Fermilab

Search for Supersymmetry Using Rare B 0 s(d) m + m - Decays at CDF Run II

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Search for Supersymmetry Using Rare B 0 s(d)  m + m - Decays at CDF Run II. Vyacheslav Krutelyov Department of Physics Texas A&M University HEP Seminar Dec 20, 2005 Fermilab. Motivations Standard Model Supersymmetry Br(B s μ + μ - ) in SM. Br(B s μ + μ - ) in SUSY - PowerPoint PPT Presentation

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Page 1: Search for Supersymmetry  Using Rare B 0 s(d)  m + m - Decays  at CDF Run II

Search for Supersymmetry Using Rare B0

s(d)Decays

at CDF Run IIVyacheslav Krutelyov

Department of Physics

Texas A&M University

HEP SeminarDec 20, 2005

Fermilab

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12/20/04 Seminar FNAL

V. Krutelyov Search for SUSY using Bs 2

Outlines

MotivationsStandard ModelSupersymmetryBr(Bsμ+μ-) in SM.Br(Bsμ+μ-) in SUSY

Loops: large tan mSUGRA,SO(10) Tree: R-parity violating models

Analysis Strategy CDF Run II Dimuon Trigger Sample

Br(Bsμ+μ-) measurement. Ingredients. Likelihood discriminant Background estimate. Signal efficiency × acceptance Optimization. Results

SUSY implications. mSUGRA SO(10) RPV

Prospects for Bsμ+μ-

Summary.

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V. Krutelyov Search for SUSY using Bs 3

Standard Model

+ Higgs

The SM describes the matter in terms of elementary particles

Quarks of 6 flavorsLeptons: charged (massive) and neutral (massless neutrinos)

and interactions are mediated by force carriers

Strong ↔ gluonsElectroweak broken (by Higgs) weak (W+ and Z0) and electromagnetic (photon)

withMasses defined by interaction with Higgs scalar

Quarks (except t) form hadrons: qqq (baryons)q-anti-q (mesons)

Bs (b anti-s), Bd (b anti-d) and B+ (u anti-b) are b-mesons with mass ~5.3GeV and lifetime ~1.6 ps will be often referred later

Hadrons change flavor only via W+ exchange

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Standard Model (status)

SM describes all collider physics observations(has been for the past 20+ years) BUT: neutrinos have masses most of the matter in the Universe is not in SMSM does not include gravitySM has naturalness (hierarchy) problemsNeed for physics beyond the SM Supersymmetry is (one of) the best choice solves gauge hierarchy problem gives a candidate for dark matter can explain neutrino masses …

+ Higgs

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V. Krutelyov Search for SUSY using Bs 5

Supersymmetry

LSP– Cold Dark Matter Candidate

SUSY Charged Current Stop L-R mixing2 Higgs Doublets: tan=vevu/vevd

•SUSY requires for each particle to be a superpartner•SM superpartners: squarks and sleptons (s=0); gauginos and higgsinos (s=1/2)•SUSY is broken at low energy

•MSSM: minimal SUSY SM extension (with 2 Higgs doublets)•EWSB w Higgs give masses

Page 6: Search for Supersymmetry  Using Rare B 0 s(d)  m + m - Decays  at CDF Run II

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V. Krutelyov Search for SUSY using Bs 6

Importance of Bs(d)

Bs(d)is a Flavor Changing Neutral Current process (FCNC)Quarks b and s are of the same electric charge

hadronic state flavor change (b anti-s)(has no charge transfer

FCNC processes are the benchmarks of the theoryDefined the construction of the SMConstrain substantially any New Physics

bshas been a golden FCNC mode for years

Bs is suggested as a new golden FCNC mode

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V. Krutelyov Search for SUSY using Bs 7

• In the Standard Model, the FCNC decay of B +- is heavily suppressed

910)9.05.3()( sBBR

• SM prediction is below the sensitivity of current experiments SM Expect to see 0 events at the Tevatron

(Buchalla & Buras, Misiak & Urban)

• Bd is further suppressed by CKM coupling (Vtd/Vts)2≈40

• Br(Bs) < 4.1×10-7 @ 90% CL ; D0 PRL 94 (2005) 042001 (240pb-1)

SM prediction

Any signal would indicate new physics!!

Bsin Standard Model

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V. Krutelyov Search for SUSY using Bs 8

• In many SUSY models, the BR could be enhanced by many orders of magnitude:

For example: - MSSM: Br(B) is proportional to tan6 - GUT SO(10) models prefer tan ≈50 (Yukawa coupling

unification)

-BR could be as large as 10-1000 times the SM prediction

Could be observable at the Tevatron

Bin SUSY: large tan

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V. Krutelyov Search for SUSY using Bs 9

’i23 i22

b

s

• Another example: R-Parity violating (RPV) SUSY•R-parity ↔ SUSY particles come in pairs

- Tree level diagram is allowed in R-parity violating (RPV) SUSY models. - No significant tandependence

- Enhancement depends stronglyon coupling constants (’

correspond to ijkqiqjk ’ijkliljk interactions

Could also be observable at the Tevatron

Bin SUSY: RPV tree

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V. Krutelyov Search for SUSY using Bs 10

• New physics may enhance Bs and Bd differently

• Minimal-flavor-violation (MFV) assumption in SUSY yields SM relations between Bs and Bd Br(Bs):Br(Bd) ≈ (Vts/Vtd)2≈40

• Can observe both Bs and Bd: unique to Tevatron (Bd only at B-factories)

• CDF has the mass resolution to distinguish two decays, M≈23MeV : unique to CDF

• Either observation or null search, will provide important clues about possible scenarios of new physics beyond SM

Monte Carlo

M(Bs)-M(Bd)~90MeV

Bsand Bd

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V. Krutelyov Search for SUSY using Bs 11

Bs(d)StrategyUse p anti-p collisions at 1.96 TeV at

Tevatron to produce Bs(d) mesons

B-hadrons are produced as a result of

(p anti-p)(b anti-b)Hadrons evolve out of b with N(B+):N(Bd

0):N(Bs0):N(b)=fu:fd:fs:fbar~4:4:1:1

N(Bs) = fs N(Hb) BR(Bs)

Use CDF detector to detect the muons from Bs(d)

of all Bs [N(Bs)] detect only

n(Bs)≡ () N(Bs)() – cceptance × fficiency

Hide signal data while choosing the best selections

Define N(Hb) from normalization mode

N(B+J/K+K+) = fu N(Hb) BR(B+K+)

BR(B+K+) ≈ 6×10-5

p

p_

ppbb_ _

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V. Krutelyov Search for SUSY using Bs 12

z

y

x))2/ln(tan(

Central Drift Chamber (COT) < 1)

Silicon Vertex Detector

Central Muon Chambers: CMU, CMP (|| < 0.6)

Central Muon Extension: CMX (0.6< || < 1)

Components relevant to the analysis are highlighted

SuperconductingSolenoid (1.4T)

CDF II33o to 53o from ┴

0o to 33o from ┴

0o to 53o from ┴

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Typical Dimuon Event

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V. Krutelyov Search for SUSY using Bs 14

•Using 364pb-1 of data (Feb02 – Aug04) from Rare B di-muon triggers:- CMUCMU 2 muons 0o to 33o from ┴

- CMUCMX 1 muon 0o to 33o from ┴ 1 muon 33o to 53o from ┴ •CMUCMU and CMUCMX channels treated independently in this analysis (background and efficiencies are different)

Search region

Rare B di-muon triggersrequire additional cuts to reduce background relative to inclusive J/ di-muon trigger

Data Sample

Background is huge

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V. Krutelyov Search for SUSY using Bs 15

Key elements in the analysis: - Construct discriminant to select Bs signal and suppress bgd

- MC simulation for signal and mass sidebands for bgd estimate

- understanding the background - accurately measure the acceptance and efficiency ratios

Analysis optimization: Figure of merit expected 90% C.L. upper limit Perform unbiased optimization

Overall picture: - Reconstruct di-muon events in the B mass window - Measure the branching ratio or set a limit - Normalize to B+J/ K+ decays

)()(

)()(

KBBRf

f

N

NBBR

s

u

B

totalB

totalBs

Bss

BsMeasurementIngredients

Nobs=Nbg+NBs

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Selection Requires:• pT(B)>4 GeV && |y(B)|<1• pT(K+)>1GeV > 2well-measured displaced vertex

= proper decay length (B+) ≈502m]

B+K+ in rare B trigger Sample: N(CMUCMU) = 1767±59

N(CMUCMX) = 698±39

Count the # of B++-K+ candidates with |M-3097|<50 MeV/c2

)(3

Bp

McL D

CMUCMU

(m

Normalization mode: B+J/K+

MJ/

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V. Krutelyov Search for SUSY using Bs 17

Pre-selection requires:• pT(B)>4 GeV && |y(B)|<1 • > 2 • well-measured displaced vertex

Bs Search Sample:N(CMUCMU) = 22459N(CMUCMX) = 14305

(completely Bgd dominated)

“Baseline” cuts select quality di-muons that should have passed the trigger,and have a well-measured vertex consistent with long-lived b-hadron decayto reject events that are clearly background (non-trigger or mis-reconstructed)

CMUCMU

Background shapes are linearfor both channels

[ (Bs) ≈468m]

BSignal Mode: “baseline selections”

Bd Bs

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V. Krutelyov Search for SUSY using Bs 18

Signal vs Background

P

P P

L3D

x

y

BBss BBss R < 1 (< 57o)

z

gbb

c

_

c_ _

gq q

_ x

yGluon SplittingGluon Splittingg g bb bb

Gluon SplittingGluon Splittingg g bb bb

z

Backgrounds are random combinations of (fake)muonsThe best look-alike is the “gluon splitting”

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Invariant +- mass, M|M-MB|<60 MeV/c2 (2.5)

sidebands: [4669, 5169] U [5469, 5969] MeV/c2 (0.50.5 GeV/c2)signal: |M-5279|<60 MeV/c2 (Bd

0) or |M-5279|<60 MeV/c2 (Bs0)

Proper decay-length (): displacement from production vtx

in B rest frame Isolation (Iso):

(fraction of pT from B within R=(2+2)1/2 cone of 1)

“pointing ()”:

(3D opening angle between Bs momentum and decay axis)

)(3

Bp

McL D

i iiTT

T

RpBp

BpIso

)1()(

)(

))(( 3DLBp

To select B events and suppress background use:

Discriminating Variables

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V. Krutelyov Search for SUSY using Bs 20

cut cut

To further reduce Bgd, apply the additional cuts:

<0.70 rad

&&Iso > 0.50

eff(signal) ≈ 92%

This leaves in data:(4.7GeV < m < 6 GeV)

N(CMUCMU) = 6242

N(CMUCMX) = 4908

~x3 down in bkg but still…~1.3K in signal window

Discriminating Variables

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V. Krutelyov Search for SUSY using Bs 21

• Use a likelihood ratio method:

ii

i

xPxPxP

ibis

isLH

)()(

)(

Ps/b is the probability for a given sig/bgd to have a valueof x, where i runs over all discriminating variables.

• The chosen variables (xi) are: - isolation (iso) - 3D pointing (),

- proper decay length probability [P()=exp(-/Bs)]

• Ps/b (PDFs) are constructed from the data sideband for background and Pythia MC for signal•LH has among the best discriminating power if xi are uncorrelated

Likelihood Ratio Discriminant)()(

)(),..(

1 xPxP

xPLH

bs

sNxx

analog of

Page 22: Search for Supersymmetry  Using Rare B 0 s(d)  m + m - Decays  at CDF Run II

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V. Krutelyov Search for SUSY using Bs 22

yx

N

iii

xy

yyxx

N

1

)ˆ)(ˆ(

1

1

Correlations between discriminating variablesare negligible allows to reduce Stat uncertainty for expected bgd estimate

Correlations between variables for Bgd

Page 23: Search for Supersymmetry  Using Rare B 0 s(d)  m + m - Decays  at CDF Run II

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V. Krutelyov Search for SUSY using Bs 23

CMU-CMU Signal and background PDFs for:

Isolation

Pointing angle

Proper decay lengthprobability

* Similar distributions for CMU-CMX

Likelihood PDFs

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V. Krutelyov Search for SUSY using Bs 24

Likelihood ratio has strong discriminatingpower between signaland background

Likelihood Ratio: Signal vs Bgd

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V. Krutelyov Search for SUSY using Bs 25

Extrapolate number of events in the side-bands tothe signal region to estimate expected background Assumes bgd events inside signal window look the same as outside

x-check this using MC and control samples Bhh (h=K decays are negligible

• Nbg = #events in signal region surviving all requirements

• NSB = #events in mass sidebands surviving pre-LH cuts

• Rmass = WidthSignal / WidthSideBand = 0.12•Assumes linear mass distribution

• RLH = fraction of bgd events expected to survive LH cut

LHmassSBbg RRNN

Estimate Background

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V. Krutelyov Search for SUSY using Bs 26

Since discriminating variables are uncorrelated, use toy MCto estimate RLH based on input distributions from data SB

KS-Prob(CMUCMU)=11%KS-Prob(CMUCMX)=5%

Likelihood Ratio Data vs Toy MC

RLH*103

Cut CMU-CMU CMU-CMX

LH>0.85 24.5±0.5 22.6±0.5LH>0.92 13.0± 0.4 12.0±0.3LH>0.99 1.4±0.1 1.5±0.1

Likelihood Ratio Rejection from Toy MC

(Errors are stat only)

LH strongly suppresses bkg

Estimate Bgd Rejection by LH cut (RLH)

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V. Krutelyov Search for SUSY using Bs 27

LHBs

KrecoBvtx

Bs

vtxB

recoBs

recoB

trigBs

trigB

Bs

B

B

B

s

1

)(

)(

• (B+/Bs) = 0.297 ± 0.008 (CMUCMU) = 0.191 ± 0.006 (CMUCMX)

• trig(B+/Bs) = 0.9997 ± 0.0016 (CMUCMU) = 0.9986 ± 0.0014 (CMUCMX)

• reco-(B+/Bs) = 1.00 ± 0.03 (CMUCMU/X)

• vtx(B+/Bs) = 0.986 ± 0.013 (CMUCMU/X)

• reco-K(B+) = 0.938 ± 0.016 (CMUCMU/X)

Pythia

MC

J/

Dat

a

DataM

C

Acceptance and Efficiency

≈1

)()(

)()(

KBBRf

f

N

NBBR

s

u

B

totalB

totalBs

Bss

var i

n opt

imiza

tion

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V. Krutelyov Search for SUSY using Bs 28

LH(Bs) cut CMU-CMU CMU-CMX

LH>0.90 (68±1)% (66±1)%LH>0.92 (65±1)% (65±1)%LH>0.95 (59±1)% (60±1)%LH>0.98 (45±1)% (48±1)%LH>0.99 (35±1)% (39±1)%

• determined from Bs MC

• MC modeling checked by comparing LH(B+) between MC and sideband subtracted Data

(stat uncertainties only)

Efficiency of LH for Bs Signal

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V. Krutelyov Search for SUSY using Bs 29

•To set a limit given observation nobs

•For a given BR and nbg the observed events nobs is given by Poisson distribution with nobs=BR + nbggiven actual nobs can use Bayesian method to extract P(BR| nobs,nbg, )

This properly accounts for uncertainties in nbg and Defines BRCL(nobs,nbg,) by CL = BR P(BR) d(BR)

Given nbg and can define a priori expected 90% CL upper limit by

To optimize: Vary event requirements to minimize BR90%CL

Optimization and Limit Setting

0

%90%90 ),,()|(n

bgCL

bgCL nnBRnnBR

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• For optimization, scan: LH>0.90-0.99, pT(B)>4-6 GeV

• Assume 1 fb-1 of data Optimal cuts: LH>0.99 and pT(B)>4GeV

•Uncertainties are included in the limit calculation Dominant uncertainty is fs/fu from PDG ~ 15%(rel)

Fragmentation ratio (Bs/B+)

Optimization Result

CMUCMU CMUCMXLuminosity 364 pb-1 336 pb-1

SES (1.0±0.2) ×10-7 (1.5±0.3) ×10-7

Nbg 0.81 ± 0.12 0.66 ± 0.13BR90% CL 3.5×10-7 5.6×10-7

BR90% CL 2.0 ×10-7Bs

S

umm

ary

SES = BR for Nsignal=1

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V. Krutelyov Search for SUSY using Bs 31

For optimized cuts of LH >0.99 and pT(B) > 4GeV and a 60 MeV window around world avg Bs(d) mass

Observed 0 event in the signal region!

Open Box

CMU-CMU Channel CMU-CMX Channel

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V. Krutelyov Search for SUSY using Bs 32

Bs: 0 events observed yields a combined limit of: 1.5×10-7 @ 90% CL 2.0×10-7 @ 95% CL

Bd: 0 events observed yields a combined limit of: 3.9×10-8 @ 90% CL 5.1×10-8 @ 95% CL

Compare to:

Br(Bs) < 4.1×10-7 @ 90% CL ; D0 PRL 94 (2005) 042001 (240pb-1)

Br(Bs) < 5.8×10-7 @ 90% CL ; CDF PRL 93 (2003) 032001 (171pb-1)

Br(Bd) < 8.0×10-8 @ 90% CL ; BaBar PRL 94 (2005) 221803 (111fb-1)

Both CDF Bs and Bd results are ×2 better than the best published result

Limits Summary

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V. Krutelyov Search for SUSY using Bs 33

• For mh~115GeV implies 10-8<Br(Bs)<3×10-7

Dedes, Dreiner, Nierste, PRL 87(2001) 251804

M0

[GeV

]

Excluded

Excluded

Excluded by this new resultneed ×3-5 improvement to exceed bsexclusion

Solid red = excluded by theory or experimentDashed red line = light Higgs mass (mh)Dashed green line = (a)susy (in units of 10-10)Black line = Br(Bs)

mSUGRA

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V. Krutelyov Search for SUSY using Bs 34

• Within mSUGRA, if Bsis observed tan is large.

Kane, Kolda, Lannon hep-ph/0310042mSUGRA scan

2.1×10-7

Run II Tevatron95% CL

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V. Krutelyov Search for SUSY using Bs 35

h2>0.13

m+

<10

4GeV

mh<

111G

eV

R. Dermisek et al., hep-ph/0304101

• New Br(Bs limit strongly disfavors this solution for mA< 500 GeV

Red regions are excluded by either theory or experimentsGreen region is the WMAP preferred regionBlue dashed line is the Br(Bs) contourLight blue region excluded by old Bs analysis

Excluded by thisnew result

SO(10) SUSY • tan()~50 constrained by unification of Yukawa coupling

• White region is not excluded

• Unification valid for small M1/2

(~500GeV)

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V. Krutelyov Search for SUSY using Bs 36

B. Dutta et al, PLB 538 (2002) 121

’i23 i22

b

s

R-parity violating SUSY

• Possible to exclude phase space ~ independent of tan

• Exclusion strongly depends on the coupling.

Excluded

RPV SUSY Exclusion

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•Optimistic: <BR>~ 1/Lumi•Additional handles on bgd exist: tighter muon ID (require CMP) calorimeter isolation additional 2D pointing use mass resolution model in LH•Combine with D0

BR(Bs) ≈ 1×10-8 at 90% CLis possible within Run II (by 09?)

•Can be measured at SM level by CMS at LHC after 2-3 years of data taking (by 10?)

Simplistic: no improvement to analysis scale Nbg and NB+ linearly with Lumi recalculate <BR>

at best ~3×10-8 at 90% CL

BsProspects

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V. Krutelyov Search for SUSY using Bs 38

Kane, Kolda, Lannon hep-ph/0310042

MSSM• It is possible to constrain mA or/and tangiven an observation of Bs

•using BR(Bs)~ tan6/mA4

•Given Minimal Flavor Violation ↔ flavor change from CKM only•Substantial enhancement is possible in non-MFV case

Dedes, Huffman PLB600 (2004) 261

tan=50MFV

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V. Krutelyov Search for SUSY using Bs 39

• Bs is a powerful probe of new physics. Could potentially provide the first hint of SUSY at the Tevatron• Using 364 pb-1 of data, CDF has obtained world best limits on Bs and Bd channels (submitted to PRL):

Br(Bs) < 1.6×10-7 @ 90% CL < 2.1×10-7 @ 95% CL

Br(Bd) < 4.2×10-8 @ 90% CL < 5.5×10-8 @ 95% CL

• The limits are now starting to constrain interesting regions of SUSY parameter space• An order of magnitude has been covered since Run I result. Will cover at least another order of magnitude before the end of RunII Hint of SUSY may just be around the corner!!

Summary

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V. Krutelyov Search for SUSY using Bs 40

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Backup Slides

BACKUP SLIDES

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1) OS- : opposite-charge dimuon, < 02) SS+ : same-charge dimuon, > 03) SS- : same-charge dimuon, < 04) FM+: fake muon sample (at least one muon failed quality cut)

LH CMU-CMU CMU-CMX cut pred obsv pred obsv

OS- >0.90 37±1 32 33±1 36 >0.99 2.8±0.2 2 3.6±0.2 3

SS+ >0.90 0.25±0.03 0 0.44±0.04 0 >0.99 <0.10 0 <0.10 0

SS- >0.90 0.35±0.03 0 0.63±0.06 0 >0.99 <0.10 0 <0.10 0

FM+ >0.90 14.2±0.4 10 3.9±0.2 3 >0.99 1.0±0.1 2 0.41±0.03 0

Check Bgd Estimate Using Control Samples

Predictions are consistent with observations

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For CMU-CMU:

• MC reproduces Data (LH>x) to 6% or better

After correction MC MC+0.01

• Assign 6% (relative) systematic

For CMU-CMX MC vs Data agreement is better

•No correction to MC is needed

Compare B+ Data and MCCheck MC Modeling of Signal LH

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• CDF-D0 working group is formed to combine the B limits from both experiments: D0 Preliminary : Br(Bs) < 3.0×10-7 @ 90% CL (D0 note 4733, ~300pb-1)

CDF Preliminary : Br(Bs) < 1.6×10-7 @ 90% CL

• Two independent groups cross-checking each other’s combined results. Aim to release preliminary combined results for LP05

• Combined CDF and D0 results is expected to improve the limit by ~20%

CDF+D0 combination

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CDF Run2.

s=1.96TeV σ(Inelastic)~60mb. ℒ ~71031cm-2s-1 (~400pb-1 good recorded)Plan: ~81031cm-2s-1 (Run2a); ~21032cm-2s-1 (4-8/fb Run 2)

1.7MHz collision20kHz L1 trigger350Hz L260Hz L3/logging rate. ~80% L1 (~1/3 at L3) of the trigger (bandwidth) are B physics

Better silicon coverage (2), muon detection, improved tracking.Better triggers: lower track pT, higher efficiency.

Run2 vs Run1

SVX II (5layer) silicon strip det svx+IP~40m

COT tracker drift chamber pT/pT

2~0.1%pT/pT

2~1.5%(L1/XFT)

CMU muon det (drift cham) pT>1.5GeV |

CMP muon det (drift cham + scint) pT>2.5GeV |

2 ft steel

2 ft steel

CMX muon det (drift cham + scint) pT>2GeV 0.6<|

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Triggers used

Dimuon trigger pT>1.5GeV, pT>2GeV, 0.6<1pT, , muon ID used to cut on tracksUsed for X)

Two Track TriggerpT>2GeV, pT, , d0 info used to cut on 2 tracksUsed for: B,Dhadrons ; D

All are input to the various Level-3 triggersThat use the offline quality information

primary vertex

secondary vertex

impact parameter

~ 1 mmb, c decays

Semileptonic trigger pT, , d0, muon ID used to cut on tracksUsed for ,D,X)no results presented in this talk

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Triggers usedDimuon trigger

pT>1.5GeV, pT>2GeV, 0.6<1pT, , muon ID used to cut on tracksUsed for X)

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Triggers usedTwo Track Trigger

pT>2GeV, pT, , d0 info used to cut on 2 tracks @L2Used for: B,Dhadrons ; D

primary vertex

secondary vertex

impact parameter

~ 1 mmb, c decays

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Br(Bs(d)μ+μ-) measurement.

Expect to detect at most few events that might only look like Bs(d)μ+μ–

SM predicts 0 events really a “search”Don’t look at the data signal region (blind search)Signal inside 5.169<MGeV/c2 (3window

demonstrate understanding of background events accurately estimate (acceptance) and

(efficiency) intelligently optimize cuts

Ldt

nnNμμ)BR(B

Bstotal

bgobsCLs 2

),(CL=90% upper limit on <nsig> for nobs

and nbg 171pb-1 or 10 trillion collisions

only Run1 Bs=0.9b for pTs>6 GeV/c, |y|<1

(use this as a baseline selection)3% (CMU&CMP Run1)

25% Run1 Dimuon trigger and pT>6GeVbaseline sample: 2940 events

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Optimization ResultsOptimize on (M, c, , Iso) to get the best expected limit

(c,,Iso) =

(>200 mm, <0.10 rad, >0.65)

and mass window 80 MeV around

world avg Bs(d): 5.369 GeV (5.279 GeV)Bs(d): total = (2.0 0.2)%

(6.6%, total30%)Accepted bgd = (6 2) fb

Expected bacground

<Bgd> in 171pb-1 = 1.1 0.3 events

Ldt

nnPnnNμμ)BR(B

Bstotal

n bgbgs 2

)|()|( Poisson prob

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R. Arnowitt et al.,hep-ph/0203069, PLB 538 (2002) 121mH

Overlap with measured δaμ (BNL)

in mSUGRA parameter space.

Overlap with dark matter=LSP allowed region.

Eliminate large parameter space (~ all for tanβ>40), with Br(Bsμ+μ-)~10-8 in Run2 (15/fb)

Motivations: Bsμ+μ- (mSUGRA)

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_

’i23 i22

b

s

c b l s

l

R. Arnowitt et al.,hep-ph/0203069, PLB 538 (2002) 121

15 fb1

2 fb1

e.g., WTRPV = ijkLiLjEk ’ijkLiQjDk ’’ijkUiDjDk

RP Violation: Br vs. m1/2

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• CDF PRL 93, 032001, 2004 (171pb-1) Expected 1.1 background Observed 1 event

2004 CDF limit BR(Bs+-)

< 5.8 × 10-7 @90% CL < 7.5 × 10-7 @95% CL•Prior to that:

•CDF[94-97] (pub 2001) <2.0×10-6 @90% CL•UA1[84-89] (pub 1991) <2.5×10-5 @90% CL

• This analysis vs CDF2004:- Using ×2 data sample- Using extended muon coverage (increased acceptance by 50%)- Lowered pT threshold on B candidate- Improve signal bgd separation using a likelihood discriminant- Significantly improved the sensitivity of the analysis

Bsa Brief History