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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. (-). s (pp →X ). Tevatron. SppS. LHC. 1mb. s (b b ). 1 m b. 1nb. 1pb.
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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
(-) s(pp→X) Tevatron SppS LHC 1mb s(bb) 1mb 1nb 1pb 0.001 0.01 0.1 1.0 10 102 √s (TeV) 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
B Heavy flavour triggers • Dilepton • 2 leptons: several Pt thresholds • Lepton + displaced track • Pt (lepton)>4 • Pt(trk)>2 + 120mm<d0<1mm • 2 displaced tracks • Pt(trk)>2 GeV, SPt >5.5 GeV • 120mm<d0<1mm d0 SVT
Displaced track trigger (SVT) Level 2 displaced track trigger • (d0) ~ 47 mm • 15 ms 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 – B0s 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 • eD2 (originally 11.3%) • Lifetime resolution st(45 fs) • Yield (25000 – 75000) • S:B (1:2 – 2:1) xs of 70 ≡ Dms of 45 SM Dms < 24.6 ps-1
Mixing status now 360 pb-1: 900 Bs Dsp: eD2 = 1.1 ± 0.2% st = 100 fs 7700 BsDsln: eD2 = 1.4 ± 0.1% st larger (missing n)
SM (Compared to 250 pb-1) 4.5 fb-1 Mixing outlook • Mixing reliant on efficiency, dilution, time resolution • Work ongoing to improve tagging, yields, decay time resolution • Baseline: • eD2 = 1.6% • st = 67 fs • Stretch: • eD2 = 2.6% • st = 47 fs
a VtdVtb* b g CP violation goals B0s mixing Via ACP of: B0pp, K p B0 D0K* B0s DsK B0 J/y K0s B0fK0s B0 J/yf for New Physics (ACP small in SM) R. Fleischer, Phys. Lett. B459 306 (1999)
CP violation now 180pb-1 analysed: ACP(Bp+ K-) = -0.04 ± 0.08 ± 0.01 ACP (BfK0s) = -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: • sin2b measured to ±0.13 ±0.076 • Assumes eD2 = 3 7.8% • g measured to 0.1 • Error on ACP in B pp as fn. lumi • Much work underway to improve tagging and event yields before these targets can be met. (Time dependent ACP ACPDIR,ACPMix)
Rare decay goals Aims of run 2: • Observe B mmX • Observe radiative decays • Eg. B K*0g (SM BR ~10-7) • Stringent limits on B mm (SM br ~ 10-10) • Deviations from SM could signal New Physics
Rare decays now Bd/Bsmm171 pb-1 BR(Bsmm) < 5.8*10-7 @90%CL Work ongoing in other modes PRL 93, 032001 2004
Rare decay outlook • In 2fb-1: • B mm limit outlook • Expected observation of : • B K*0g • Yellow book predicts ~60 events (for BR B K*0mm =1.5 x10-6) • B mmX • Yellow book predicts 100-300 B+mmK, 400-1100 B0mmK0
Summary CDF projected results by 2009: B0s mixing measured (for all SM values of Dms) Measurements of b and g 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 …
COT Nucl. Instrum. Meth. A526: 249, 2004 96 layers, radii 0.3-1.4m 4 axial superlayers (12 wires) 4 stereo superlayers (±35 mrad) 200mm hit resolution Dpt/pt = (0.7 0.1pt)% dE/dx for e/p/K/p 1.2sp/K if pt>2 GeV
Silicon 750 000 channels! Impact parameter resolution 13 + 40/pt mm Layer00: 2cm radius, single sided SVX: 2.5-10cm radius, 5 layers, double sided ISL: 20-30cm radius, 1-2 layers, double sided
H. G. Moser, A. Roussarie, NIM A384 (1997) Bs mixing In practice: use amplitude scan method • introduce amplitude to mixing probability formula • evaluate at each Dm point • Amplitude=1 if evaluated at correct Dm • Allows us to set confidence limit when 1.645s=1