B physics: new states, rare decays and branching ratios in CDF

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1 B physics: new states, rare decays and branching ratios in CDF Vyacheslav Krutelyov Texas A&M University For CDF Collaboration July 1, 2004 BEACH04 Chicago, IL

2 Outlines CDF Run2 Detector Triggers Searches B s(d) µ + µ D 0 µ + µ Measurements (successful searches) X(3872) B + J/ψ π + B s φφ and pentaquarks See talks by S.D Auria and D.Litvintsev BEACH04 2

3 Tevatron performance As you know the Tevatron is working very well this year Record initial luminosity = cm -2 s -1 ( cm -2 s -1 to CDF) Detector efficiency ~85-90% ~450pb -1 on tape pb -1 used for analysis so far BEACH04 3

4 η =1 η =0.6 2 ft steel 2 ft steel CDF Run2. CMP muon det (drift cham + scint) p T >2.5GeV η <0.6 CMU muon det (drift cham) p T >1.5GeV η <0.6 SVX II (5layer) silicon strip det σ svx+ip ~40µm η =1 η =0.6 COT tracker drift chamber δp T /p T2 ~0.1% δp T /p T 2 ~1.5%(L1/XFT) CMX muon det (drift cham + scint) p T >2GeV 0.6< η <1 s=1.96tev σ(inelastic)~60mb. L ~ cm -2 s -1 (~400pb -1 good recorded) Plan: ~ cm -2 s -1 (Run2a); ~ cm -2 s -1 (4-8/fb Run 2) 1.7MHz collision 20kHz L1 trigger 350Hz L2 60Hz L3/logging rate. ~80% L1 (~1/3 at L3) of the trigger (bandwidth) are B physics Run2 vs Run1 Better silicon coverage ( 2), muon detection, improved tracking. Better triggers: lower track p T, higher efficiency. BEACH04 4

5 Triggers used All are input to the various Level-3 triggers That use the offline quality information Dimuon trigger p T >1.5GeV, η <0.6 p T >2GeV, 0.6< η <1 p T, φ, muon ID used to cut on tracks Used for ψ,υ,β µµ(+x) Two Track Trigger p T >2GeV, η <1 p T, φ, d 0 info used to cut on 2 tracks Used for: B,D hadrons ; D µµ Semileptonic trigger p T, φ, d 0, muon ID used to cut on tracks Used for ψ,d,β µ(+x) no results presented in this talk primary vertex ~ 1 mm b, c decays secondary vertex impact parameter BEACH04 5

6 Triggers used Dimuon trigger p T >1.5GeV, η <0.6 p T >2GeV, 0.6< η <1 p T, φ, muon ID used to cut on tracks Used for ψ,υ,β µµ(+x) BEACH04 6

7 Entries χ / ndf / 28 amplitude ± center ± σ ± intercept (lin. bg) ± amplitude (exp. bg) 1.118e+15 ± 3.447e+15 decay const. (exp. bg) ± Triggers used Two Track Trigger p T >2GeV, η <1 p T, φ, d 0 info used to cut on 2 Used for: B,D hadrons ; D µµ primary vertex ~ 1 mm secondary vertex impact parameter b, c decays 2 Events / GeV/c CDF Run II Preliminary, 66±4 pb ± B φ K 13.4 ± 5.7 Events ± Data Fit φ Sideband 0 BEACH04 ± 2 B Candidate Mass [GeV/c ]

8 B(D) µµ: Theoretical motivations. Current limits. Flavor Changing Neutral Current. Loop contribution only in SM. Br SM (B s µ + µ - )=(3.4±0.5) 10-9 Br SM (B d µ + µ - )=(1.00±0.14) (hep-ph/ ) Br SM (D 0 µ + µ - )~3*10-13 (GIM suppressed) Only upper experimental limit exists: Br exp (B s µ + µ - )< % C.L. CDF Br exp (B d µ + µ - )< % C.L. Belle Br exp (D 0 µ + µ - )<4.1(4.2)* % C.L. BEATRICE(E771) Limits are far away from the SM value: can test for a possible new physics. MSSM: Br(B µ + µ - ) enhanced by tanβ>10 terms ~tan 6 β. Up to 100 over the SM prediction. R-parity violating models give tree level contributions. Not heavily constrained by other observables. Can be seen in Run2 (esp. B s µµ) Other models enhance less. E.g., universal extra dimensions. Up to +70% for B s µ + µ - b µ ν λ i23 λ i22 BEACH04 8 s msugra,so(10) RPV µ

9 D 0 µµ search Use D *± D 0 π ± tagged events Use D 0 π + π as a normalization mode. Blind from µid in 1.840<m µµ <1.882 GeV Cuts: d 0 (μ,π) >120μm, d xy (D 0 ) <150μm Δφ(μμ)>0.085 Background: combinatorial (from right sideband) expect 1.5±0.7 misidentification (punch-through/decay) expect N(D 0 π + π ) P(misID) 2 0.3±0.1 Br( D NCL( D µµ ) ε( D ππ) 0 µµ ) Br( D ππ) 0 0 N( D ππ) ε( D µµ ) BEACH04 9

10 D 0 µµ search 69pb -1 B(D 0 µµ)<2.4 90% C.L. B(D 0 µµ)<3.1 95% C.L. This result improves on the previous limits by ~ 2 ( from BEATRICE, and from E771 at 90% C.L.) BEACH04 10

11 Br(B s(d) μ+μ-) measurement. BR(B s µµ) 3% (CMU&CMP Run1) 2 α ε ( n σ, n Expect to detect at most few events that might only look like B s(d) μ+μ N total obs SM predicts 0 events really a search Don t look at the data signal region (blind search) Signal inside 5.169<M µµ <5.469 GeV/c 2 (±3σ window) demonstrate understanding of background events accurately estimate α (acceptance) and ε (efficiency) intelligently optimize cuts CL 25% Run1 Bs bg ) Ldt CL=90% upper limit on <n sig > for n obs and n bg 171pb-1 or 10 trillion collisions only Run1 σ Bs =0.9µbfor p T Βs >6 GeV/c, y <1 (use this as a baseline selection) Dimuon trigger and p T >6GeV baseline sample: 2940 events BEACH04 11

12 Signal & Background Need to select discriminating variables that leave most of the signal and remove most of the background. R < 1 (φ < 57 o ) P T µµ B s s µµ P T µ Φ y P µ T P vtx T x Most Promising Discriminating Variables Invariant mass M cτ : L xy Pt (B) 2D lifetime c Φ : φ(p TB ) φ(vtx) Isolation: P (B) P t (B) t + R <1 P t (trk) Largest expected background: gluon splitting g bb µµ BEACH04 12

13 Optimization Results Optimize on (M µµ, cτ, Φ, Iso) to get the best expected limit BR(B s µµ) (cτ, Φ,Iso) = (>200 mm, <0.10 rad, >0.65) and mass window ± 80 MeV around world avg Bs(d): GeV (5.279 GeV) = Bs(d): α ε total = (2.0 ± 0.2)% (α 6.6%, ε total 30%) Accepted bgd σ = (6 ± 2) fb Expected bacground <Bgd> in 171pb -1 = 1.1 ± 0.3 events n N( n n ) P( n n ) Poisson prob 2 α ε total bg σ Bs bg Ldt BEACH04 13

14 Observed limits BR(B s µ + µ ) < 5.8x10 7 (7.5x % C.L.) 90% C.L. 3 times better than Run I (previous world best) BR(B d µ + µ ) < 1.5x10 7 (1.9x % C.L.) 90% C.L. slightly better than (1.6x % C.L., just published) B-factory/Belle result BEACH04 14

15 for SUperSYmmetry C.L.) SO(10) R. Dermisek et al., hep-ph/ R-parity violating R. Arnowitt et al., PLB 538 (2002) 121, new plot by B.Dutta new CL Dark matter allowed region New limit excludes significant amounts of the previously allowed SUSY models parameters (more to go) BEACH04 15

16 Spectroscopy Exotic States X(3872) New narrow state observed first by Belle in decay modes J/ψπ + π Charmonium state not expected near mass peak. D* Dbar deuteron-like molecule? CDF confirms X in 220pb -1 Preference for M(ππ) > 500MeV 670±90 candidates, sign.~ 12σ Mass scale using ψ(2s) peak BEACH04 16

17 X(3872): Long-lived fraction CDF II CDF II II Long-lived fraction: F X(3872) =16.1 ± 4.9 ± 2.0 % cf F ψ(2s) = 28.3 ± 1.0 ± 0.7 % BEACH04 17

18 B J/ψ π + Cabibbo-suppressed decay B + J/ψπ + Br Expected to be 5% relative to Br(B + J/ψK + ) Br(B + J/ψπ + )/Br(B + J/ψK + )=4.2 ± 0.7% PDG02 Signal selection p T (B + )>6.5GeV, p T (K + )>2GeV, L xy >200µm BEACH04 18

19 Summary Great physics results are coming in from CDF Br(B s µµ)<5.8x10-7 at 90% C.L. Br(B d µµ)<1.5x10-7 at 90% C.L. Br(D µµ)<2.4x10-6 at 90% C.L. X(3872) confirmation accepted/published by PRL Long-lived fraction F X(3872) =16.1 ± 4.9 ± 2.0 %. BEACH04 19

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