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Risultati recenti di BaBar

a. g. b. Risultati recenti di BaBar. [Una selezione dalle conferenze estive]. CSN1 Napoli 19/09/2005 Giuseppe Finocchiaro Laboratori Nazionali di Frascati. Run5. Run4. Run2. Run3. Run1. The gold rush. (Where `gold’ is no longer J/ y K s )

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Risultati recenti di BaBar

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  1. a g b Risultati recenti di BaBar [Una selezione dalle conferenze estive] CSN1 Napoli 19/09/2005 Giuseppe Finocchiaro Laboratori Nazionali di Frascati

  2. Run5 Run4 Run2 Run3 Run1 The gold rush • (Where `gold’ is no longer J/yKs) • Most analyses in this talk used the Run1-4 dataset (~240fb-1) • KEKB delivered ~470fb-1 so far G. Finocchiaro @ CSN1 Napoli 2005

  3. (The usual) disclaimer • Hard selection required in this talk (75 BABAR abstracts @LP05, 57 @EPS05) • In spite of ‘sub-optimal’ PEP-II performance this year so far, still competitive wrt Belle • “Di necessità virtù”: BABAR‘s analysis power generally (still) compensates for smaller integrated statistics • More physics channels • Better detector (PID, vtx) • More efficient analyses G. Finocchiaro @ CSN1 Napoli 2005

  4. Indice • Angoli (I): g, a • Lati (I): |Vub| da b→uℓn • sin2b: (persistenti) indizi di NP • Lati (II): |Vtd/Vts| da b→d/s g • Ancora nuovi stati: la Y(4260) • Non parlerò di: • (SM:10-40) • B→tn [<2.610-4@90%CL] (SM:8.1±2.510-5) • B→Ksp0g [hep-ex/0507038] (SM:L.H. g sin2b~0.04) • Conclusioni, prospettive G. Finocchiaro @ CSN1 Napoli 2005

  5. b→ucs b→cus UT angles: g • From direct CPV in the decay of charged B’s • Interfering tree amplitudes w/ CP-violating relative weak phase g and CP-conserving relative strong phase d • Interference if D0/D0 decay into identical final state • CP-eigenstate decay: Gronau-London-Wyler (GLW) • Doubly-Cabibbo-suppressed (DCS) decay: Atwood-Dunietz-Soni (ADS) • Dalitz plot analysis of 3-body decay, e.g., : Giri-Grossman-Soffer-Zupan (GGSZ) G. Finocchiaro @ CSN1 Napoli 2005

  6. It all depends on rB… • Sizable interference only if large enough amplitude ratio • Unfortunately, BABAR finds small rB • Error on g vs. rB • rB≈0.12  30o error on gw/ current BABAR data  need to add more channels/data From CKM factors & color suppression G. Finocchiaro @ CSN1 Napoli 2005

  7. Right Sign Wrong Sign ~90 events ~4 events WSB+ WSB- mES (GeV/c²) New GLW and ADS signals in hep-ex/0507002, submitted to PRL hep-ex/0508001 DCS decay CP-eigenstate decay D0→flavour non-CP B+ D0 CP+→K+K-, p+p- B+ B- B- D0 CP-→KSp0, KSw, KSf B+ B+ B- B- NCP+=37.6±7.4 NCP-=14.8±5.9 G. Finocchiaro @ CSN1 Napoli 2005

  8. m2- D0 D0 m2+ +rBei(-g+dB) A(B-)=|A(B→D0K-)|× m2- m2+ GGSZ DP analysis of • The idea in pictures: • CP-conjugate B- and B+ decay amplitudes • g is the same, r(*) and d(*) depend on the mode Assume D decays conserve CP… G. Finocchiaro @ CSN1 Napoli 2005

  9. DP analysis of D0/D0 decays hep-ex/0507101 • Extract D0(bar) decay amplitudes from DP analysis of independent cc sample with flavor-tagged decays from • New K-matrix model: 9 BW resonances + K-matrix formalism for  s-wave • Deals with broad, overlapping, multi-channel scalar resonances 91fb-1 82k D0s G. Finocchiaro @ CSN1 Napoli 2005

  10. 227×106 BB Mode Signal events ~ ~ ~ ~ ~ ~ B-D0K− 282 ± 20 D0K- D*0[D00]K- D*0[D0]K- ~ ~ B-D*0[D00]K− 90 ± 11 ~ ~ B-D*0[D0]K− 44 ± 8 ~ B-D0K*−[K0Sp-] 42 ± 8 ~ B-D0K*−[KSp-] NEW Signals in all modes hep-ex/0504039, accepted by PRL hep-ex/0507101 G. Finocchiaro @ CSN1 Napoli 2005 (mES>5.27 GeV/c²)

  11. ~ ~ ~ D0K- D*0K- D0K*- 2sCL g(deg) 1s CL (stat.+syst. uncertainties) 2 fold (±p) ambiguities for bothganddB rB r*B .rs (<0.75@2s CL) GGSZ DP results: g vs. r(*)B hep-ex/0507101 all D()K() modes combined: g=(67±28stat±13syst±11DP)o G. Finocchiaro @ CSN1 Napoli 2005

  12. BABARonly:: Putting it all together… • … we can measure g!!!! • 3 theoretically clean (= w/o penguins) methods to measure g • did not mention TD D(*)rp… (no new measurement) • Small r()Bvery hard measurement, but no longer “mission impossible” • No single channel dominates • To improve precision, need more data/channels G. Finocchiaro @ CSN1 Napoli 2005

  13. B0B0mixing Tree decay Penguin decay g  b b→uud UT angles from TD asymmetries Preamble: CPV from interference of decay and mixing • Specific example is for , but valid in general • Single CKM phase in decay ↔ Cf=0 (no direct CPV) G. Finocchiaro @ CSN1 Napoli 2005

  14. a=p-(b+g) κpp a and the penguins: more triangles are needed • Difficult to reliably estimate how much penguins contribute • B(B0K+p-) (~ pure penguin) indicates they cannot be neglected • Gronau/London analysis • Assuming isospin symmetry, these triangular relations between the Bhh amplitudes hold: • The B and B triangles do not match, and 2aeff = 2a+κpp • Need to measure 5 BFs, including B(B0p0p0) from tagged samples • still a 8-fold ambiguity • Grossman/Quinn bound:

  15. Measuring a in B→rr decays • Tough analysis [VV state, (p0p+)(p0p-), r’s are wide] • However: (~6 times x B→pp) (isospin triangle collapses to a line) • Small penguin contribution: |a-aeff|<11o@ 68%CL (almost pure CP-even state) 232M BB PRL 95 041805 (2005) G. Finocchiaro @ CSN1 Napoli 2005

  16.  from B→pp/rr/rp decays • All three modes give consistent and complementary measurements of  • constraint rather weak due to large penguin contamination • rryields single most precise constraint • TD analysis of 3 Dalitz plot in rp. Weak constraint at 90% CL, but disfavors rr mirror solution near 170o G. Finocchiaro @ CSN1 Napoli 2005

  17. α VtdVtb* VudVub* γ β VcdVcb* UT sides: |Vub| Tree-level process (charmless semileptonic) • NP free • ‘complementary’ (opposite in the UT) to sin2b BF(b→u l n) measured from inclusive and exclusive s.l. branching fractions • From inclusive (partial) s.l. BFs using O.P.E. • reliable prediction of totalB→Xuℓn decay rate • experiment measures partial BFs (hard cuts against B→Xcℓn) • biggest uncertainty in extrapolation of BF(b→u ln) to full phase space from motion of b quark in B meson • Parameters measured e.g. from E*g in b→sg PRD72 052004 (2005) G. Finocchiaro @ CSN1 Napoli 2005

  18. 89MBB signal region sideband region hep-ex/0506036 submitted to PRL signal 232MBB hep-ex/0507017 Inclusive |Vub| measurements 88MBB • Electron endpoint spectrum • Electron and n momentum • Lepton and hadronic system recoiling against fully-reconstructed B mesons hep-ex/0408075, being submitted to PRD G. Finocchiaro @ CSN1 Napoli 2005

  19. LQCD LCSR |Vub| from exclusive measurements: untagged Bpℓn 83M BB, hep-ex/0507003, subm. to PRD Exclusive s.l. BFs  |Vub| using form factors (FFs) in bins of q2 • several approaches LCSRs, LQCD, quark models … • FF uncertainties affect measurement twice • FF shape  acceptance  try and measure on data • FF normalisation in extraction of |Vub| from pBF (~10-15%) for -0.15<DE<0.25 GeV |Vub|=(3.82±0.14stat±0.22syst±0.11FF– 0.52FFnorm)x10-3 +0.88

  20. Incl. vs. Excl. : which wins? Indirect |Vub| determination Inclusive • Improved expt. error: 4% • Very much improved theory error ( OPE parameters): 6% • Exclusive • Improved expt. error: 4% • Theory error still dominant: ≥15% • Experimental input, i.e., FF shape, will reduce theory error in the future • Measurements now compatible within errors G. Finocchiaro @ CSN1 Napoli 2005

  21. Why this is relevant • constraints from TREE process only • Gauge the UT in any extension of the SM • Firm starting point for NP searches UTfit JHEP 0507:028,2005 G. Finocchiaro @ CSN1 Napoli 2005

  22. J/y BO KS sin2b from charmonium [to find NP, must know OP] • Reference point for NP • C=0 (only 1 phase) • S=-hfsin2b • Precise! • Validation of SM predictions • sin2b[UTFit]=0.793±0.033 (sides) [0.734±0.024 (all)] • In fact, a big success… New Belle meas. (357M BB): sin2b=0.652±0.044 G. Finocchiaro @ CSN1 Napoli 2005

  23. Why b→s penguins are good for NP • Small effects (e.g. from propagators of heavy particles circulating in the loop) more easily detectable since Tree is missing • CKM factors same as J/yKs • If single phase, SMpredicts: Speng=Scharmonium=sin2bCpeng=Ccharmonium=0 • Naïve [HFAG] average of penguin modes 2.7s below charmonium note: BABAR and Belle have ~same precision G. Finocchiaro @ CSN1 Napoli 2005

  24. To find NP, must know OP (II) • In fact, we know that > 1 amplitude/phase is (usually) involved • e.g., b→uus CS tree (g) in channels involving non-strange neutral mesons • Even J/yKs could have penguins • DS=0.000±0.017 [hep-ph/0507290] • Is there a dominant one? Intense theoretical work lately • Dsin2b always >0 (contrary to experiment) • some predictions quite precise • theory parameters constrained to measured BF (will further improve) • Averaging still not meaningful QCD factorization: [Cheng,Chua,Soni, hep-ph/0506268] [Beneke, hep-ph/0505075] Dsin2b G. Finocchiaro @ CSN1 Napoli 2005

  25. hep-ex/0507087 New signals (~230M BB) in [h,K+K-]KL0 hK0and K+K-K0 have largest BF among b→s modes • hKS0has smallest stat. error on sin 2b • hKL0adds 50% more events (1245±67 total) • ShK0=0.36±0.13±0.04, ChK0=-0.16±0.09±0.03 • SK+K-K0L=0.07±0.28±0.12, CK+K-K0L=0.54±0.22±0.09 • Using fCP-even =0.89±0.08±0.06 sin2bK+K-K0=0.41±0.18±0.07±0.11 hep-ex/0507016 G. Finocchiaro @ CSN1 Napoli 2005

  26. 2.7s? This could be one of the greatest discoveries of the century, depending, of course, on how far down it goes… CPV in b→s penguins • Intriguing difference from b→c remains G. Finocchiaro @ CSN1 Napoli 2005

  27. b→dg • Large background • Only accessible through exclusive modes Brg, wg • Simultaneous fit to B+→r+g, B0→r0g, B+→wg assuming Belle claim observation hep-ex/0408034 G. Finocchiaro @ CSN1 Napoli 2005

  28. α VtdVtb* VudVub* γ β VcdVcb* UT sides: |Vtd/Vts| • Constraint used to come entirely from Dmd/Dms • (smaller theoretical uncertainty on ) • Now radiative penguins sufficiently precise to start providing meaningful UT constraints, using: • Low B→r/w gBF favors small |Vtd| FF ratio z2=0.85±0.1 Ali et al., Eur.Phys.J.C23:89-112,2002 difference in dynamics DR 0.10.1 DR=0 in this plot G. Finocchiaro @ CSN1 Napoli 2005

  29. 6.1σ 2.5 σ JPC= 1 : y(2S), y(3770), … New States: X(3872)→J/yp+p- • Discovered by Belle in 2003 in • 3872 is just above open-charm threshold • Confirmed by D0, CDF, BABAR • isovector  charged partner(s) must exist • ruled out @10-4CL by BABAR in B0(+)→X+K-(0) • searched in B0(+)→X0(J/yp+p-)K0(+) decays • Need more data to discriminate among different models • Does not fit in standard charmonium spectroscopy • why does not decay onto DD? • J/yr isospin violating (but is a r?) • [qq][qq] [Maiani et al. PRD71, 014028 (2005)]: R=1, Dm=7±2MeV/c2 • D*0D0 molecule [PRD71, 074005 (2005)]: R<0.1 • Search in ISR events R=BF(B0→XKS)/BF(B±→XK±)=0.5±0.3±0.05 Dm=2.7±1.3±0.2 MeV/c2 G. Finocchiaro @ CSN1 Napoli 2005

  30. y(2S) ...no sign of X(3872) in ISR, but... hep-ex/0506081 • Discover Y(4260)→J/yp+p-!! 232fb-1 Peak cross section ~50pb • Just above DSDS threshold • Could be two states Very robust signal. Among other tests: • Split by run, J/y decay mode • search in J/y sidebands • require gISR (25% of events) • change/reverse selection • feed-down e.g. from undetected p0 • Use y(2S) for optimisation/validation • fit for null signal with • different bkgd shapes • bin sizes • check for reflections

  31. Where else? Y(4260) No trace in R-scan • shad=(14.2±0.6) nb • sY~50pb • accuracy of R~4% • no surprise it‘s not seen in R • But why a dip? • And why does not decay to DD? √s (GeV) • Feeble signal (so far) in • B-→J/yp+p-K- • 3.1s, assuming mISR, wISR • need more data G. Finocchiaro @ CSN1 Napoli 2005

  32. Summary & outlook • CPV in mixing↔decay (and decay) well established • Precision in measurements of CKM parameters steadily improving • The Standard Model resists (surprisingly well…) • New states keep popping up in unexpected places • renewed interest in spectroscopy, new models proposed and being scrutinized • Finding NP is the name of the game now • Deviations from sin2b in b→s penguin getting smaller (~1s for most modes) • In general, processes with clear SM predictions are good candidates • B→tn around the corner? 2008 (?) 2005 G. Finocchiaro @ CSN1 Napoli 2005

  33. g from B→DK sin2b in penguins • from rr The next few years • Statistical uncertainties have scaled so far faster than (adding new channels) • Even for J/yKs systematics not an issue, for several ab-1 yet • Theory often feeded by exptl. measurements • also improves with more data • Expected precision on UT angles vs. time: G. Finocchiaro @ CSN1 Napoli 2005

  34. Our analysis commitments BaBar in Italia Milano: analisi dipendenti dal tempo in decadimenti senza charm e misure di BF (h()K/p, h()KS/L, h()w, h()f, hh, hh,a1p, h()K/Ksg) Torino: decadimenti senza charm a due corpi (pp, Kp, KK), Vub (recoil) Trieste: B→D*D*,Vcb (B→D*ln), BD(*)DsJ ° ° ° ° Genova: charmonio (B cc  adroni, B cc[hCg]K), t  mg Padova: Vcb (B→D*ln), Vub, vita media e mixing del B,t→mg, CPV nel mixing ° o ° Ferrara: Vub, Vcb e charmonio sul rinculo Pisa: sin2b/CP/CPT, vita media del t, t→Kspp0n,DK Dalitz per l'estrazione di g,b→sg inclusivo, B→D*ln, B→D0CPK(p0), B→D*tn ° Perugia: BD*DS*, DSfp, tmg, CPV dal lato di tag, CPV nel mixing ° ° ° ° Roma I: sin(2b+g), BDSp/K, DKS, b→sg sul rinculo, mixing del B, X(3872), Vub, DK Dalitz per l'estrazione di g, decadimenti senza charm e analisi dipendenti dal tempo per l'estrazione di a (pp, Kp, KK), t→mg, sin2b dai pinguini (fKS, fKL, KSKSKS ,K+K-KL,KSp0, K*g), B→fK+ LN Frascati: BD*D*,BD*DS*, DSfp, gISRK*+K-, gISRfh/p0, CPV nel mixing Napoli: Vcb (B→D*ln), B→J/yK/p, B→tn, decadimenti semileptonici Bari: decadimenti a 3 corpi della D, DsJ*(2317)+, DsJ*(2460)+ (analisi di Dalitz) G. Finocchiaro @ CSN1 Napoli 2005

  35. Backup slides G. Finocchiaro @ CSN1 Napoli 2005

  36. L-scaling of channels for angles measurements G. Finocchiaro @ CSN1 Napoli 2005

  37. How NP would be constrained • NP (assuming only in loops) parameterised as From tree measurements G. Finocchiaro @ CSN1 Napoli 2005

  38. N=45±10 N=57±14 hep-ex/0507005, preliminary • sensitive to relative contribution of -, Z-penguin and box diagram • new physics can show up in any of these Event yields in 229M BBbar smallest BF from B’s measured to date! RK = 1.06  0.48  0.05 [SM:~1] RK*= 0.93  0.46  0.12 [SM:~0.75] ACP(K)=-0.08 0.22 0.11 [SM:~0] ACP(K*)=+0.03 0.23 0.12 [SM:~0] soon to come: forward-backward asymmetry G. Finocchiaro @ CSN1 Napoli 2005

  39. K*(890) non-K* hep-ex/0507038, submitted to PRL 232M BB B→Ksp0g • Phase in B→K*0 g between mixed and unmixed decay is 2 • W couples only to left-handed quark: b→sL • interference suppressed in SM: Smix -2ms/mb sin2b -0.04 sin2 • possibly large enhancement from NP • can use Ks0 even if not from resonance (Atwood et al (2004)) Compatible w/ SM Errors still large G. Finocchiaro @ CSN1 Napoli 2005

  40. B→tn • CKM fit predicts • Direct measurement of fB (currently only from LQCD) • B→tn /Dmd constraints |Vub/Vtd| • > 2 n in the event. Analysis: • Use hadronic or semileptonic tag • 1 or 3 prong topology • Can constrain SUSY parameters We’re almost there! G. Finocchiaro @ CSN1 Napoli 2005

  41. (NP in) b→d/s g • FCNC • sensitive to NP @ EW scale • solid SM predictions: • BF(B→Xsg)=(3.6±0.30)10-4 • ACP~0 • Huge backgrounds • cuts on g or Xs spectra ↔ model dependence • Fully inclusive (no requirement on Xs/d) • lepton tag [/1200 on Bkg (/20 on Sig)] • topology cuts, p0h vetoes • Exclusive (semi-inclusive) b→sg • reconstruct Xs→K+np+mp0 (n,m<5) • 38 states,55% of all possible G. Finocchiaro @ CSN1 Napoli 2005

  42. Partial Branching Fractions (PBF) B rest frame (4s) frame b→d/s g spectra, BF, ACP Inclusive Semi-inclusive ACP(b s g+ b d g) = (- 0.010 0.115 0.017 ) hep-ex/0506043 LP Paper-100 hep-ex/0403004 G. Finocchiaro @ CSN1 Napoli 2005

  43. favored suppressed favored suppressed rD=0.060±0.003, from D*+[K± p] p+ rB~0.1÷0.3 0.93±0.04 g from B-[K+p-]K-: ADS method • Equalize the interfering amplitudes (PRL 78, 3257) • Extract g from decay rates measurements G. Finocchiaro @ CSN1 Napoli 2005

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