B physics outlook at

Tara Shears

Outline

• B physics at CDF– production– triggering

• B physics outlook (+ some current results)– Mixing– CP violation– Rare decays / new physics

• Summary

B production at CDF

Similar production cross-sections to LHC

bb production cross-section high

So is charm

So is inelastic …

All B species produced in same ratio as LHC

Bs sector can be explored before LHCb

√s (TeV)0.001 0.01 0.1 1.0 10 102

1mb

1b

1nb

1pb

SppSTevatron

LHC(pp→X)(-)

(bb)

Heavy flavour triggers

Dilepton

2 leptons: several Pt thresholds

Lepton + displaced track

Pt (lepton)>4

Pt(trk)>2 + 120m<d0<1mm

2 displaced tracks

Pt(trk)>2 GeV, Pt >5.5 GeV

120m<d0<1mm SVTBd0

Displaced track trigger (SVT)

Level 2 displaced track trigger

(d0) ~ 47 m– 15 s operation

• online primary vertex finding, tracking

• trigger on displaced tracks (large d0)

• n.b. cross-sections grow with luminosity….

Data taking outlook

4.4 – 8.5 fb-1 forecast by end 2009

2.5 – 5 fb-1 by mid-2007

600 pb-1 on tape now

Typically 350pb-1 analysed

Physics

• Focus on projected CDF B physics highlights – B0

s mixing, CP violation, rare decays– Taken from “yellow book” hep-ph/0201071

• Show current achievements

• Translate this into future expectation where possible

B0s mixing goals

Needed prior to CP violation measurements

Within 2fb-1 CDF should cover SM allowed range

Sensitivity originally estimated as function of

D2 (originally 11.3%)

Lifetime resolution t(45 fs)

Yield (25000 – 75000)

S:B (1:2 – 2:1) xs of 70 ≡ ms of 45

SM ms < 24.6 ps-1

Mixing status now

360 pb-1:

900 Bs Ds:

D2 = 1.1 ± 0.2%

t = 100 fs

7700 BsDsl:

D2 = 1.4 ± 0.1%

t larger (missing )

Mixing outlook

Mixing reliant on efficiency, dilution, time resolution

Work ongoing to improve tagging, yields, decay time resolution

Baseline:

D2 = 1.6%

t = 67 fs

Stretch:

D2 = 2.6%

t = 47 fs

(Compared to 250 pb-1)

SM

4.5 fb-1

CP violation goals

Via ACP of:

B0 , K

B0 D0K*

B0s DsK

B0 J/ K0s

B0 K0s

B0 J/ for New Physics (ACP small in SM)

B0s mixing

VtdVtb*

R. Fleischer, Phys. Lett. B459 306 (1999)

CP violation now180pb-1 analysed:

ACP(B+ K-) = -0.04 ± 0.08 ± 0.01

ACP (BK0s) = -0.07 ±0.17 +0.03-0.02

(47 events) hep-ex/0502044

Triggered by SVT:

ID via dE/dx or ToF information

CP violation outlook

Yellow book predictions for 2fb-1:

sin2 measured to ±0.13 ±0.076

Assumes D2 = 3 7.8%

measured to 0.1

Error on ACP in B as fn. lumi

Much work underway to improve tagging and event yields before these targets can be met.

(Time dependent ACP ACP

DIR,ACPMix)

Rare decay goals

Aims of run 2:– Observe B X– Observe radiative decays

• Eg. B K*0 (SM BR ~10-7)

– Stringent limits on B (SM br ~ 10-10)

– Deviations from SM could signal New Physics

Rare decays now

PRL 93, 032001 2004

Bd/Bs 171 pb-1

BR(Bs ) < 5.8*10-7

@90%CL

Work ongoing in other modes

Rare decay outlook

In 2fb-1:

B limit outlook

Expected observation of :

B K*0

Yellow book predicts ~60 events (for BR B K*0 =1.5 x10-6)

B X

Yellow book predicts 100-300 B+ K, 400-1100 B0 K0

Summary

CDF projected results by 2009:B0

s mixing measured (for all SM values of ms)

Measurements of and in unitarity triangle to ±0.1

Observation of rare decay modes and indirect test of New Physics production

Note: all forecasts dependent on reaching predicted performance, receiving planned luminosity …

Backup slides

COTNucl. Instrum. Meth. A526: 249, 2004

96 layers, radii 0.3-1.4m

4 axial superlayers (12 wires)

4 stereo superlayers (±35 mrad)

200m hit resolution

Dpt/pt = (0.7 0.1pt)%

dE/dx for e//K/p

1.2 /K if pt>2 GeV

750 000 channels!

Impact parameter resolution 13 + 40/pt m

Layer00: 2cm radius, single sided

SVX: 2.5-10cm radius, 5 layers, double sided

ISL: 20-30cm radius, 1-2 layers, double sided

Silicon

Trigger system

(thanks to Rolf Oldeman)

mttBBNtBBN

tBBNtBBNtA

ssss

ssss

cos

))(())((

))(())(()(

0000

0000

In practice: use amplitude scan method• introduce amplitude to mixing probability formula

• evaluate at each m point• Amplitude=1 if evaluated at correct m • Allows us to set confidence limit when 1.645

H. G. Moser, A. Roussarie, NIM A384 (1997)

Bs mixing

Mixing systematics

Bs yields