# Presentation: 481167

## B physics: new states, rare decays and branching ratios in CDF

**Vyacheslav Krutelyov**
**Texas A&M University**
***For *****CDF Collaboration**
- July 1, 2004
- BEACH04
- Chicago, IL

## Outlines

- CDF Run2
- Detector
- Triggers
- Searches
- Bs(d) 
- D0 
- Measurements (successful searches)
- X(3872)
- B+J/
- Bs and pentaquarks
- See talks by S.D’Auria and D.Litvintsev

- S. Krutelyov     B physics: new and rare    BEACH04

- 7/1/04

## Tevatron performance

- As you know the Tevatron is working very well this year
- Record initial
- luminosity = 84  1030 cm-2s-1
-                               (92  1030 cm-2s-1 to CDF)
- Detector efficiency ~85-90%
- ~450pb-1 on tape
- 100-200+ pb-1 used for analysis so far

- S. Krutelyov     B physics: new and rare    BEACH04

- 7/1/04

## CDF Run2.

- s=1.96TeV  σ(Inelastic)~60mb.   L ~71031cm-2s-1 (~400pb-1 good recorded)
- Plan: ~81031cm-2s-1 (Run2a); ~21032cm-2s-1 (4-8/fb Run 2)
- 1.7MHz collision20kHz L1 trigger350Hz L260Hz 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~40m

- COT  tracker drift chamber pT/pT2~0.1%
- pT/pT2~1.5%(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<|

- 

- 

- S. Krutelyov     B physics: new and rare    BEACH04

- 7/1/04

## Triggers used

- Dimuon trigger
- pT>1.5GeV, pT>2GeV, 0.6<1
- pT, , muon ID used to cut on tracks
- Used for X)

- Two Track Trigger
- pT>2GeV, 
- pT, , d0 info used to cut on 2 tracks
- Used for: B,Dhadrons  ; D

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

- Semileptonic trigger
- pT, , d0, muon ID used to cut on tracks
- Used for ,D,X)
*no results presented in this talk*

- S. Krutelyov     B physics: new and rare    BEACH04

- 7/1/04

## Triggers used

- Dimuon trigger
- pT>1.5GeV, pT>2GeV, 0.6<1
- pT, , muon ID used to cut on tracks
- Used for X)

- S. Krutelyov     B physics: new and rare    BEACH04

- 7/1/04

## Triggers used

- Two Track Trigger
- pT>2GeV, 
- pT, , d0 info used to cut on 2 tracks  @L2
- Used for: B,Dhadrons  ; D

- S. Krutelyov     B physics: new and rare    BEACH04

- 7/1/04

## B(D): Theoretical motivations. Current limits.

- B(D): Theoretical motivations. Current limits.

- Flavor Changing Neutral Current. 	          Loop contribution only in SM.
- BrSM(Bsμ+μ- )=(3.4±0.5)  10-9
- BrSM(Bdμ+μ- )=(1.00±0.14)  10-10 (hep-ph/0303060)
- BrSM(D0μ+μ- )~3*10-13  (GIM suppressed)
- Only upper experimental limit exists:
- Brexp(Bsμ+μ- )<2.010-6  90% C.L.  CDF RunI @100/pb.
- Brexp(Bdμ+μ- )<1.610-7  90% C.L.  Belle ‘03 @78/fb.
- Brexp(D0μ+μ-)<4.1(4.2)*10-6  90% C.L. BEATRICE(E771)

- Limits are far away from the SM value: can test for   a possible new physics.
- MSSM: Br(Bμ+μ-) enhanced by tanβ>10 terms ~tan6β. Up to 100 over the SM prediction.
- R-parity violating models give tree level contributions. Not heavily constrained by other observables.
- Can be seen in Run2 (esp. Bs)
- Other models enhance less. E.g., universal extra dimensions. Up to +70% for Bsμ+μ-

- RPV

- mSUGRA,SO(10)

- S. Krutelyov     B physics: new and rare    BEACH04

- 7/1/04

## D0search

- Use D*±D0π± tagged events
- Use *D**0**********  *as a normalization mode.
- Blind from ID in 1.840<m<1.882 GeV
- Cuts:
- |d0(μ,π)|>120μm, |dxy(D0)|<150μm
- Δφ(μμ)>0.085
- Background:
- combinatorial (from right sideband) – expect 1.5±0.7
- misidentification (punch-through/decay) – expect N(*D**0********** *)P(misID)20.3±0.1

- S. Krutelyov     B physics: new and rare    BEACH04

- 7/1/04

## D0search

*D**0***search

- B(*D**0***)<2.410-6 @ 90% C.L.
- B(*D**0***)<3.110-6 @ 95% C.L.
- This result improves on the previous limits by ~2              (4.110-6 from BEATRICE, and 4.210-6 from E771 at 90% C.L.)

**69pb****-1**

- S. Krutelyov     B physics: new and rare    BEACH04

- 7/1/04

## 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<MGeV/c2  (3window
- demonstrate understanding of background events
-  accurately estimate  (acceptance)  and  (efficiency)
-  intelligently optimize cuts

- CL=90% upper limit on <nsig> for nobs and nbg

-    171pb-1 or 10 trillion collisions

- only Run1 Bs=0.9b for pTs>6 GeV/c, |y|<1
- (use this as a baseline selection)

- 3% (CMU&CMP Run1)

- 25% Run1

- Dimuon trigger and pT>6GeV
- baseline sample: 2940 events

- S. Krutelyov     B physics: new and rare    BEACH04

- 7/1/04

## Signal & Background

- Need to select discriminating variables that leave most of the signal and remove most of the background.

**P****T********

**P****T********

**********

***x***

***y***

***B******s***** ******** ********

*******R***** < 1 **
**(**********<**** ****57****o****)**

- 

- Largest expected background:
- gluon splitting  gbb

- 

- S. Krutelyov     B physics: new and rare    BEACH04

- 7/1/04

## Optimization Results

- Optimize 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%, total30%)
- Accepted bgd  = (6  2) fb
-     Expected bacground
-       <Bgd> in 171pb-1 = 1.1  0.3 events

- Poisson prob

- S. Krutelyov     B physics: new and rare    BEACH04

- 7/1/04

## Observed limits

- BR(Bsμ+μ) <  5.8x107  90% C.L.    (7.5x107  95% C.L.)
- 3 times better than Run I (previous world best)
- BR(Bdμ+μ) <  1.5x107  90% C.L.    (1.9x107   95% C.L.)
- slightly better than (1.6x107  90% C.L., just published)                       B-factory/Belle result

- S. Krutelyov     B physics: new and rare    BEACH04

- 7/1/04

##   for SUperSYmmetry (@95% C.L.)

- New limit excludes significant amounts of the previously allowed SUSY models parameters (more to go)

- Dark matter
- allowed region

- new exclusions @95% CL

- S. Krutelyov     B physics: new and rare    BEACH04

- 7/1/04

## Spectroscopy – Exotic States X(3872)

- New narrow state observed first by Belle in            decay modes J/
- Charmonium state not expected near mass peak.
- D* Dbar deuteron-like molecule ?
- CDF confirms X in 220pb-1
- Preference for M( ) > 500MeV
- 670±90 candidates, sign.~ 12
- Mass scale using (2S) peak

- S. Krutelyov     B physics: new and rare    BEACH04

- 7/1/04

## X(3872): Long-lived fraction

- Long-lived fraction:
- FX(3872)=16.1  4.9  2.0 %
*cf*   F(2S) = 28.3  1.0  0.7 %

**CDF II**

**CDF II**

**CDF II**

- S. Krutelyov     B physics: new and rare    BEACH04

- 7/1/04

## BJ/

- Cabibbo-suppressed decay B+J/
- Br Expected to be 5% relative to Br(B+J/K+)
- Br(B+J/+)/Br(B+J/K+)=4.2  0.7% PDG02
- Signal selection
- pT(B+)>6.5GeV, pT(K+)>2GeV, Lxy>200m

- S. Krutelyov     B physics: new and rare    BEACH04

- 7/1/04

## Summary

- Great physics results are coming in from CDF
- Br(*B**s***)<5.8x10-7 at 90% C.L.
- Br(*B**d***)<1.5x10-7 at 90% C.L.
- Br(*D***)<2.4x10-6 at 90% C.L.
- X(3872) confirmation
- Long-lived fraction FX(3872)=16.1   4.9  2.0 %
- .

- accepted/published
- by PRL

- S. Krutelyov     B physics: new and rare    BEACH04

- 7/1/04

## Slide 20

- S. Krutelyov     B physics: new and rare    BEACH04

- 7/1/04

## BACKUP SLIDES

- S. Krutelyov     B physics: new and rare    BEACH04

- 7/1/04

## Data Samples

- OS+ : opposite-sign muon pairs, ctau > 0
-       our signal sample – not used for xchecks
-  OS- : opposite-sign muon pairs, ctau < 0
-  SS+ : same-sign muon pairs, ctau > 0
-  SS- : same-sign muon pairs, ctau < 0

- S. Krutelyov     B physics: new and rare    BEACH04

- 7/1/04

## 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(Bsμ+μ-)~10-8 in Run2 (15/fb)

- 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(Bsμ+μ-)~10-8 in Run2 (15/fb)

- Motivations: Bsμ+μ-  (mSUGRA)

- S. Krutelyov     B physics: new and rare    BEACH04

- 7/1/04

## RP Violation: Br vs. m1/2

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

***e.g.*****,***** W*****TRPV ****=*****    ***********ijk****L****i****L****j****E****k **************’****ijk****L****i****Q****j****D****k **************’’****ijk****U****i****D****j****D****k**

- RP Violation: *Br* vs. *m*1/2

- S. Krutelyov     B physics: new and rare    BEACH04

- 7/1/04

## Bhh PR plot

- now ~1K events with 180/pb

- S. Krutelyov     B physics: new and rare    BEACH04

- 7/1/04

## Bd(s) : Run I Results

***M***********[GeV/c****2****]**

********************

******_****_******_****_

**CDF, PRD 57, 3811 (1998)**
********* ******L*****d*****t***** ****= 98 pb********1 ****(~5 **x **10****12**** collisions)**** **
***B******d*****: 5.205-5.355 GeV/*****c*****2**
***B******s*****: 5.300-5.450 GeV/*****c*****2**
**N****obs**** = 1 with 5.344 GeV/*****c*****2**
**(consistent with an expectation from the Standard Model backgrounds)**
***Br*****(*****B******d*************** ) < 8.6**x**10********7**** (95% C.L.)**
***Br*****(*****B******s*************** ) < 2.6**x**10********6**** (95% C.L.)**

*B**d*(*s*)** : Run I Results

- S. Krutelyov     B physics: new and rare    BEACH04

- 7/1/04