B Physics at CDFResults and Prospects

Iván Vila Instituto de Física de Cantabria, Spain

Lake Louise Winter InstituteLake Louise, Canada - 15th -22nd February 2003

Feb 18th 2004 I. Vila Lake Louise Winter Institute 2004 2

In this talk Introduction Cross-section Masses Lifetimes Spectroscopy Rare Decays CP Violation Bs Mixing

DISCLAIMER: 1001 B and Charm physics analysis at CDF

Here not at all exhaustive summary

Feb 18th 2004 I. Vila Lake Louise Winter Institute 2004 3

B physics at Tevatron Large b production cross-section

(bb) ~ 50b (5kHz @ E32) (bX, |y(b)|≤1) ~ 30b (3000Hz @ E32) compare: (bb) ~ 1nb at (4S) ( 10Hz @ E34)

Many B hadrons states produced: B0, B+, Bs, b, Bc, b

But… HUGE inelastic cross section ~ 100mb A dedicated selective trigger needed vs.

B factories inclusive trigger.

Feb 18th 2004 I. Vila Lake Louise Winter Institute 2004 4

B Triggers Di-lepton - dilepton sample

pT(/e)>1.5/4.0 GeV/c J/ modes, masses, lifetime, x-section Yield 2x Run I (low Pt threshold, increased acceptance)

lepton + displaced track - semileptonic sample pT(e/)>4 GeV/c 120 m<d0(Trk)<1mm, pT(Trk)>2 GeV/c Semileptonic decays, Lifetimes, flavor tagging. B Yields 3x Run I

Two displaced vertex tracks - hadronic sample pT(Trk)>2 GeV/c, 120 m<d0(Trk)<1mm, S pT>5.5 GeV/c Branching ratios, Bs mixing, …

primary vertexsecondary vertex

impact parameter

~ 1 mmb, c decays

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Feb 18th 2004 I. Vila Lake Louise Winter Institute 2004 5

B production – Cross Section

RunI b cross-section ~ 3x NLO QCD theoretical approaches: new

physics, Next-to-Leading-log resummations, non perturbative fragmentation function from LEP, new factorization schemes…

Only top 10% in Pt of the total x-section measured

New measurements to lower pT(B) : Inclusive J/Psi cross section up to

PT(J/Psi)=0 (first time hadron collider)

Bottom Quark Production cross-section

Feb 18th 2004 I. Vila Lake Louise Winter Institute 2004 6

B Lifetimes and Masses Test of HQET predictions

Inclusive measurements (J/ X dimuon sample) Still statistical limited ~ 138 pb-1

First measurement of b using a exclusive reconstruc.

Lifetime measurements using the inclusive semileptonic sample are still under progress (expect results soon)

Mass fit using fully reconstructed B J/ X decays

B0, B+ competitive with PDG, and Bs and b the World’s best measurement

Feb 18th 2004 I. Vila Lake Louise Winter Institute 2004 7

Spectroscopy – Exotic States X(3872) New narrow state observed first by Belle in decay modes

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

/J

Feb 18th 2004 I. Vila Lake Louise Winter Institute 2004 8

Rare decays - Bs,Bd BR(Bs ) ~ 10-9 in SM (SUSY physics two orders of

magnitude enhancement) Blind analysis optimized for 300-400 pb-1 (~ 1 0.3

expected bkg)

Limits at 90% C.L.BR(Bs->MuMu) < 5.8 E-7BR(Bd->MuMu) < 1.5 E-7

Bs factor 3 better than best published limit (Run I) Bd slightly better than Belle’s at LP03: 1.6 E-7@90%CL Still room for improvement: Acceptance & bkgs

Feb 18th 2004 I. Vila Lake Louise Winter Institute 2004 9

CPV - Two body charmless decays B h+h-

1. extracting the signal

Time dependent asymmetry Bd ( angle) and Bs KK ( angle) Direct CP asymmetry of the self tagging modes Bd K and Bs K

Online hadronic selection + B pointing prim. vertex, displaced & isolated

2. Separation of the components dE/dx ~ 1.3 for K/ separation Statistical separation is still possible Unbinned log-likelihood fit defined including

Kinematical variables M() and =(1-p1/p2)q1 dE/dx

Mode Yield (65 pb-1)

B0 K 14817(stat.) 17(syst)

B0 3914(stat.) 17(syst)

Bs KK 9017(stat.) 17(syst)

Bs K 311(stat.) 17(syst)

Feb 18th 2004 I. Vila Lake Louise Winter Institute 2004 10

CPV - Direct ACP Selftagging Modes - Projections First observation Bs

KK Direct ACP violation ~ 0

Feb 18th 2004 I. Vila Lake Louise Winter Institute 2004 11

Bs mixing – Signal Reconstruction Bs mixing unique to CDF requires

Event yield Clean signals (S/B) Vertexing resolution Tagging effectiveness: D2

)(09.0)(03.0)(05.035.0)(

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Fully reconstructed decays boost resolution

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CDF Golden Channel Bs Ds fst 67

Feb 18th 2004 I. Vila Lake Louise Winter Institute 2004 12

Bs Mixing - Flavor tagging Flavor taggers optimized on

high statistics semileptonic sample

Unbiased performance in high purity inclusive sample

CDF Results:Same-side (B+) D2(2.10.7)%Muon tagging D2 (0.70.1)%JQT, SET almost thereOSKT NEW! RunII on progress

Feb 18th 2004 I. Vila Lake Louise Winter Institute 2004 13

Bs Mixing – Improvements Idealistic “Yellow Book” projections

Detector acceptance and trigger efficiency very improved 2x Bs selection

Under current conditions (BsDs ) S = 1600 events/fb-1 S/B = 2/1 D2 = 4 % (SLT+SST+JQT) t=67 fs

Modest improvements Adding Ds K*K,KsK y Bs Ds3

S = 1600 events/fb-1 2000 events/fb-1

L00 innermost silicon layer, event by event beam-line reconstruction

D2 = 5 %

t=67 fs t=50 fs

Feb 18th 2004 I. Vila Lake Louise Winter Institute 2004 14

Bs Mixing – Projections Short term 500 pb-1 (no improvement up to 2005)

2(for ms = 15 ps-1) Reach the current indirect limit. Cover the Standard Model favored range

Beyond the SM favored range (conservative improvements up to 2008): 5 if ms = 18 ps-1 with 1.8 fb-1 5 if m = 24 ps-1 with 3.2 fb-1

Feb 18th 2004 I. Vila Lake Louise Winter Institute 2004 15

Summary and Conclusions After 2003 fall shutdown the Tevatron is performing very well. CDF Run II accumulated over 290pb-1 of data (~ 2.5 larger than

Run I). The new displaced track trigger has been a great success CDF is back in the game of producing world class results.

(Unique Bs,b physics, competitive Bd, Bu physics in same cases) Benchmark lifetime and mass analysis probe excellent detector

performance World best limits Bs and Bd First observation of Bs KK modes CPV in B hh, CDF major player in this arena. Bs mixing:

Reach current indirect limit with 500pb-1 (end 2004) 5sensitivity over SM preferred range (up to 24 ps-1) in 3fb-1(end

2008)