Matthew Martin Johns Hopkins University for the CDF collaboration

Matthew Martin

Johns Hopkins University

for the CDF collaboration

SB0 0bandBranching Ratios from

Flavor Physics & CP Violation

Ecole Polytechnique, Paris, France

June 2003

M.Martin, Johns Hopkins for CDF, FPCP June 2003

Outline:• Motivation

• Branching Ratios at CDF

• Results from:

B h h

0S SB D

0b c

• Conclusions


• Precision study of the :– BR’s, mass and lifetime– Plan to observe or rule out SM mixing– Measure – Measure

• The world’s largest sample:– BR’s, mass and lifetime– CP Violation searches

• This program just beginning…

CDF plans a rich program of B-Physics:

0b

0SB

SB

0SB


What we know:

PDG 2002:NEW !

NEW !

0SB

New results for:

0S sB D

0SB K K


NEW !

What we know: 0b

PDG 2002:

Nearly New results for: 0b c


Hadronic Level 2 Trigger:

-500 -250 0 250 500

silicon trigger impact parameter (µm)

Tra

cks

per

10 µ

m

0

4

000

8

000

0 10 20 30 40 50 Silicon trigger latency (µs)

E

vent

s pe

r 0.

5 µ

s

0

100

00

20

000

35m 33mresol beam = 48m •Interaction rate

•Reduced to on Level 2 output.

•Critical component : SVT impact parameter cuts.

•2 Tracks with

2.5MHz

300Hz

120IP m

~

~


Branching Ratios at CDF:

• Cancellation:

– Systematics in Trigger and Reconstruction Efficiency.

• Production fractions ( ):

– LEP/CDF Combined.

– Aim to measure at CDF.

• Daughter BR’s :– Rely on existing measurements.

– Future : CLEO-C

• Plan to normalise to same channel Semileptonic

0 0

0 0

0

0

( )( )

( ) ( )d b

b d

Bb baryon b c

b d d cB

N BR D Kf BR

f BR B D N BR pK

b

f

• Compare search mode to kinematically similar mode, eg:


Normalisation mode:

• Same mode for:

• Similar cuts to signal

• also visible.

0dB D

0S SB D

0b c

*D


Reconstructing: 0S SB D

1.013 1.028K K

m GeV

sD

4t sp D GeV

2D-Dist Prim 400sD m

2D-Flight-Dist 100sB m

Impact-Par 100sB m

4t sp B GeV

Important Cuts:2 Tracks required to be Trigger Tracks.

mass constrained to

PDG value

First Observation!


Systematics:

Uncertainty in due to fit. s

d

B

B

N

N

s

d

B

B

N

N

0.008

0.008sB

dB

Particle

Uncertainty in s

d

B

B

Source /s dB B

XFT 1-miss

Min b quark tp

B lifetimes

D lifetimes

Total

0.001

0.08

0.02 0.04

0.00 0.04

0.08 0.06 BR Total Syst: 0.07

Due to MC


Results:( )

0.44 0.11( ) 0.11( ) 0.07( )( )

s s s

d d

f BR B Dstat BR syst

f BR B D

From PDG: 0.273 0.034 :s

d

f

f

( )1.61 0.40( ) 0.40( ) 0.26( ) 0.20

( )s s s

d d

BR B D fstat BR syst PDG

BR B D f


Reconstructing 0b c

Important cuts:

2tp P GeV

0from 2t bp GeV

0 225bct m

0from 65c bct m

0Impact-Par 100b m

2.265 2.303cm GeV

Confirm Trigger

4.5t cp GeV

0 7.5t bp GeV


b Reflections:

•3 Types of reflection:

•4-Prong Decays

(eg )

•Other decays

•Everything else.

•Normalise Reflection shape to measured

yield.

0dB D

0b

0dB D


Effect of dE/dX:No

dE

dxproton

dE

dx


Expected Systematics:

B lifetime0 lifetimeb

Dalitz structurec

b spectrumtp0 , polarisationb c

XFT 1 miss

Phi efficiency

Total

negligible

4 5

11

2

33

6 5

Size %Source


Current Status:

( ) 25%cBR pK

0

0

( )

( )baryon b c

d d

f BR

f BR B D

• Finalising reflection model

measurement for EPS

• Systematic uncertainty dominated by:

~


Prospects for improving normalisation:

Note : Hadronic Trigger Path


B h h • required to be trigger tracks.

• Optimise offline Cuts on MC signal, data sideband:

Reconstructing

h h

1 2 5.5t tp p GeV

1 2, 150IP IP m

2D-Flight-Dist 300B m

80BIP m

• Isolation:

•Efficiency from data

tB daughters

tAll Tracks

p

Ip

•Defined in a cone about the B axis:

/B J K


Different signal contributions:

dE

dx

• Total width due to several different contributions.

• on top of each other

• Disentangle using:

• Invt Mass

• Relative momentum

• PID

,d sB B K K PID essential

← Most Important

{Kinematic Separation

Monte Carlo:


Kinematic separation:• Choose 2 variables:

• Signal Likelihood:2

( )1 1exp ( )

22

M MF P

dB

0 /dB K K 0 /dB K K

/sB K K sB K K

/sB K K

M

11

2

1p

qp

1 2where: p p

Monte Carlo:


Particle ID :

• calibrated on sample

• Bachelor charge identifies daughters.

0D

2

1, 1,

1 1exp 1 2

22

ij jj

i j jii

M MF P G ID G ID

dE

dx*D

/dE dx


Systematics:d

d

B

B K

BCK Shape

dM B

sM B

M

MC stat

/dE dx

+0.019 -0.015

+0.004 -0.004

+0.005 -0.006

+0.004 -0.009

+0.002 -0.002

+0.05 -0.05

+0.002 -0.009

+0.0003 -0.0003

+0.002 -0.003

dirCPA K

+0.006 -0.005

+0.007 -0.007

+0.01 -0.01*

* new calibration will reduce systematic


Current Results:0

0

( )0.26 0.11( ) 0.055( )

( )d

d

BR Bstat syst

BR B K

Yields:

0dB K

0dB

0sB K

0sB KK

3 11(stat)

90 17(stat)

148 17(stat)

39 14(stat)

dirCPA = 0.02 0.15(stat) 0.17(syst)K

PDG 2002:

0

0

( ) 0.13 0.010.290.12 0.02( )

d

d

BR B

BR B K


Conclusions:

• First measurement of relative BR • First observation of

– Measurement of validates extraction procedure

• Expect and for EPS• First steps toward an exciting programme in

physics and physics (mixing and CPV) .0b

0SB

• CDF has robust signals in:0b c

0S SB D

sB K K

0S SB D

sB K K0

0

( )

( )d

d

BR B

BR B K

0b c

sB K K

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Matthew Martin Johns Hopkins University for the CDF collaboration

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