B physics outlook at Tara Shears Outline B

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 crosssection high So is charm So is inelastic … All B species produced in same ratio as LHC Bs sector can be explored before LHCb (pp→X) Tevatron Spp. S LHC s(bb) 1 mb 1 nb 1 pb 0. 001 0. 1 1. 0 10 102 √s (Te. V)

Heavy flavour triggers Dilepton 2 leptons: several Pt thresholds Lepton + displaced track Pt (lepton)>4 Pt(trk)>2 + 120 mm<d 0<1 mm 2 displaced tracks Pt(trk)>2 Ge. V, SPt >5. 5 Ge. V 120 mm<d 0<1 mm B d 0 SVT

Displaced track trigger (SVT) Level 2 displaced track trigger – (d 0) ~ 47 mm – 15 ms operation • online primary vertex finding, tracking • trigger on displaced tracks (large d 0) • 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 350 pb-1 analysed

Physics • Focus on projected CDF B physics highlights – B 0 s mixing, CP violation, rare decays – Taken from “yellow book” hep-ph/0201071 • Show current achievements • Translate this into future expectation where possible

B 0 s mixing goals Needed prior to CP violation measurements Within 2 fb-1 CDF should cover SM allowed range Sensitivity originally estimated as function of e. D 2 (originally 11. 3%) Lifetime resolution t(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: e. D 2 = 1. 1 ± 0. 2% t = 100 fs 7700 Bs Dsln: e. D 2 = 1. 4 ± 0. 1% t larger (missing n)

Mixing outlook Mixing reliant on efficiency, dilution, time resolution Work ongoing to improve tagging, yields, decay time resolution SM Baseline: e. D 2 = 1. 6% t = 67 fs Stretch: e. D 2 = 2. 6% t = 47 fs (Compared to 250 pb-1) 4. 5 fb-1

CP violation goals a Vtd. Vtb* B 0 s mixing b g Via ACP of: B 0 pp, K p B 0 D 0 K* B 0 s Ds. K B 0 J/y K 0 s R. Fleischer, Phys. Lett. B 459 306 (1999) B 0 f. K 0 s B 0 J/yf for New Physics (ACP small in SM)

CP violation now 180 pb-1 analysed: ACP(B p+ K-) = -0. 04 ± 0. 08 ± 0. 01 ACP (B f. K 0 s) = -0. 07 ± 0. 17 +0. 03 -0. 02 (47 events) hep-ex/0502044 Triggered by SVT: ID via d. E/dx or To. F information

CP violation outlook Yellow book predictions for 2 fb -1: sin 2 b measured to ± 0. 13 ± 0. 076 Assumes e. D 2 = 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 ACPDIR, ACPMix)

Rare decay goals Aims of run 2: – Observe B mm. X – Observe radiative decays • Eg. B K*0 g (SM BR ~10 -7) – Stringent limits on B mm (SM br ~ 10 -10) – Deviations from SM could signal New Physics

Rare decays now Bd/Bs mm 171 pb-1 BR(Bs mm) < 5. 8*10 -7 @90%CL Work ongoing in other modes PRL 93, 032001 2004

Rare decay outlook In 2 fb-1: B mm limit outlook Expected observation of : B K*0 g Yellow book predicts ~60 events (for BR B K*0 mm =1. 5 x 10 -6) B mm. X Yellow book predicts 100300 B+ mm. K, 400 -1100 B 0 mm. K 0

Summary CDF projected results by 2009: B 0 s 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 …

Backup slides

Nucl. Instrum. Meth. A 526: 249, 2004 96 layers, radii 0. 3 -1. 4 m 4 axial superlayers (12 wires) 4 stereo superlayers (± 35 mrad) 200 mm hit resolution Dpt/pt = (0. 7 0. 1 pt)% d. E/dx for e/p/K/p 1. 2 p/K if pt>2 Ge. V COT

Silicon 750 000 channels! Impact parameter resolution 13 + 40/pt mm Layer 00: 2 cm radius, single sided SVX: 2. 5 -10 cm radius, 5 layers, double sided ISL: 20 -30 cm radius, 1 -2 layers, double sided

Trigger system

(thanks to Rolf Oldeman)

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. 645 s=1 H. G. Moser, A. Roussarie, NIM A 384 (1997)

Mixing systematics

Bs yields