CDF: Stato dell analisi

Transcription

1 1 CDF: Stato dell analisi SOMMARIO Stato generale dell analisi a CDF Top/EWK physics highlights b/c physics INFN - Riunione della CSN 1 Roma 17 Maggio 2004 Giovanni Punzi SNS/INFN-Pisa

2 2 Data used for spring 2004 CDFII data analysis Data set collected February 02 Sep pb -1 delivered, 400 pb -1 on tape, <240 pb -1 used for analysis Much progress since Sep 03 Reconstruction software improvements The flow of physics results has begun - many recent blessing Italian group is giving key contributions Will cover only highlights with emphasis on Italian work Top quark EWK B physics

3 3 Italian group contributions B/charm physics Topics: B hh (A CP, BR), Λ b pπ, B s D s π & lνd s (for B s mixing), B s φφ, B d φk*, B φk (A CP, BR), D 0 hh (BR, A CP ), D +!!!, pentaquark search Groups involved: Padova, Pisa, Roma, Trieste High pt physics Topics: Z bb, Higgs searches, top physics, hadronic top, top backgrounds, b- tagging, W+jets, forward W s Groups involved: Bologna, Padova (Trento), Pisa, Roma Responsibilities: Conveners of B physics group & special committees (Bs) Members of important review committees Contributions to basic analysis tools Most work in close cooperation amongst Italian groups A lot of work in close cooperation with non-italian group

4 4 Basic tools: tracking Great progress in Si stand-alone Substantial efficiency improvement at large η and low-pt Improved mass resolution L00 now ready for physics: eff. 60% and growing Clear improvement in σ crucial for Bs mixing NEW

5 Basic tools: PID 5 Improved TOF t0 (reduce tails) Improved COT dedx ->separation Silicon dedx starting up π K p K π TOF: >1σ K/! separation up to p=2 GeV de/dx in COT K/! sep. >1.4σ@Pt>2GeV (was 1.2) dedx in Silicon Vertex for low-pt tracks PLAN: combine them all!

6 CDFII Physics Results 6 5 Low-Pt papers produced Charm cross-section, Ds-D+ mass, D0->µµ, Bs->µµ, X(3872) First High-Pt paper submitted 27/4 t-tbar cross section from dileptons 23 paper drafts currently under review 6 Low-Pt 4 EWK 6 Top 5 Exotics 2 QCD A long list of blessed results going through internal review Many more papers will be drafted in upcoming months

7 7 Hi-Pt

8 8 W,Z Summary σ(w,z) From the ratio: Γ W = 2071 ±40 (MeV/c 2 ) CDF II (e)1.1< η <2.8 First-time use of Forward region thanks to SVX+ISL Standalone tracking

9 1st Run II top paper: Top-> dileptons 9 channel ee µµ eµ Expected (scaled to 13 total obsv d) 3.3 ± ± ± 0.8 Observed Flavor distribution consistent with SM expectation σ = (stat) (sys) ± 0.4 (lumi) pb (hep-ex/ )

10 10 Top mass: l + jets Choose events with 4 jets, 1 vertex tag 28 events in 162 pb -1 with estimated bckg of 7.0 ± 0.8 Syst. uncertainty dominated by jet-energy scale. Best determination from DLM: m t = (stat) ± 6.2 (sys) GeV

11 11 All-hadronic top Counting method Kinematic selection + 1b- tag Observe: 326 on 264±17 background σ = 7.8 ± 2.5 (stat) (syst) pb

12 Run II Top Summaries 12 PRL submitted 04/27/04 Top Mass PRD draft in preparation PRD draft in preparation PRD draft in preparation PRD draft in preparation PRL Combination Optimizing the mass scale Will follow cross sections

13 13 Low-Pt

14 Rare decays: B d(s) µ + µ 14 Background Data BR C.L. BR C.L. B s µ + µ ± B d µ+ µ ± Best world result for B s (improves CDF Run I x3) 1 event in the overlap region Blind analysis: cuts were optimized before looking at the signal mass region Slightly better results than Belle and BaBar for Bd

15 Bs SO(10) µ+µ implications for SUSY R. Dermisek et al., hep-ph/ R. Arnowitt et al., PLB 538 (2002) 121, R-parity violating new plot by B.Dutta New limit excludes significant amounts of the previously allowed SUSY models parameters - Expect ~10May with 1fb-1 15

16 B VV Polarization Amplitudes 16 B d J/ψK*, B s J/ψφ ϖ Prerequisite for ΔΓ s Test of factorization hypothesis B s J/ψφ B d J/ψK* A 0 2 = 0.63 ± 0.04 ± 0.03; φ : 3.07 ± 0.40 A 2 = 0.18 ± 0.05 ± 0.05; φ : 0.11 ± 0.23 A 0 2 = 0.59 ± 0.07 ± 0.03 A 2 = 0.23 ± 0.10 ± 0.01 World best results

17 B VV Lifetimes 17 The other ingredient to measure ΔΓ s A lot of work to understand systematic uncertainties to O(1µm) level B s J/ψφ ct distribution τ ± ± τ ± ± τ ± τ τ ± τ τ ± Competitive with PDG

18 18 Charm & more Charm syst CDF is publishing the World s best A(D 0 KK) = 2.0 ± 1.2± 0.6 % BR &ACP measurement in D0 decays A(D 0 ππ ) = 1.0 ± 1.2 ± 0.6 % Now going for BR and ACP of D+->!!! - No experiment ever had >1500 ev BR known at 10% will become 1% Unique possibility to see ACP in Charm ~190 pb-1 55,000 events!

19 Updating B->hh BR& direct ACP 19 Bd ππ = 160 ± 27 Bd Kπ = 542 ± 30 separated by dedx+kinematics Bs KK = 225 ± 29 Bs Kπ = 28 ± 25 ACP(Bd Kπ) = ± 0.07 Substantial yields in 180pb-1 Bd yields = 80fb-1 Babar RAW yields for the moment Update of LP03 result at ICHEP04 Direct Acp(K!) to 7% (Babar 5%@same yield) BR(BsKK) to 15% -> Constraints angle γ

20 B + φk + 20 Pure-penguin, b->sss decay Sensitive to Vts and NP BR & direct-a CP (180pb -1 ) BR A CP

21 First Observation of B s φφ 21 Another B->sss penguin process QCDF expectation somewhat smaller: Good S/B! 5σ significance Blind analysis, optimized according to physics/ With more statistics, can get larger yields by looser cuts FUTURE: Angular analysis (yields a γ measurement)

22 B Flavor Tagging 22 OST (opposite side tagging): B s produced in pairs tag flavor of opposite B JETQ: sign of the weighted average charge of opposite B-Jet SLT: sign of soft lepton from decay of opposite B SST (same side tagging): B 0 (B 0 ) is likely to be accompanied by a π+ (π ) Search for the track with minimum P T REL Kaon taggers (new in CDF): OST (K from b c s transition) SST (K from fragmentation) Evaluation in progress, expectations between 5-10% Learning process in runii no faster than runi... εd 2 [%] CDF-II CDF-I Soft muon 0.7 ± 0.2 Soft electron in progress e+µ 2.1±0.5 Jet charge 0.4 ± 0.02 * 2.2 ± 1.3 Same Side 1.0 ± ± 0.5 Opp. side kaon in progress N/A Same side kaon in progress N/A *simpler algorithm

23 23 Welcome back B d mixing xd Compatible with expectation. Same Side Tagging only

24 24 Hadronic Yields for Bs mixing Currently ~1.5pb of hadronic + ~1pb needing reflection cleanup Need 2pb and εd 2 = 5% for 5σ sensitivity up to 24ps -1 in 3.2 fb -1 - xs is the most complex of all B measurement - Need to combine many ingredients - Ad-hoc coordination (1/2 italian) - Italy is on the front line

25 25 A final note What it is like to produce physics in this environment? More refined and complex analysis than in run I Large base samples, O(10 6 ) events (hadronic triggers) Keep up with software revisions/conference deadlines Large CPU usage, with peaks Large skimmed subsamples on disk Blind analysis - Complex, multidimensional cut optimization Large samples of realistic MC, simulate detector/trigger conditions vs time Precision measurements, lots of work on control samples e.g. dedx (fit 10 3 parameters on 10 6 events) Some analysis had smaller samples - but still need huge calibrations samples -> requirements are not different Many analyses at the same time It was all possible only thanks to italian-specific resources Generic users need weeks to run through data samples It is working, and we would like to keep it that way

26 26 Backup

27 27 Search for Hi-mass dileptons M(Z )>750 GeV (RunI >GeV)

28 28 Pentaquark Searches at CDF pk 0 S (Fit excludes signal region) invariant mass spectrum

29 29 W+jets production

30 30 The B c, rediscovered CDF Run signals abovebackground + (electron) (muon)