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1 Review of Charm Hadronic Decays and Lifetimes Werner Sun, Cornell University (and CLEO-c) 7 th International Conference on Hyperons, Charm, and Beauty Hadrons 2-8 July 2006, Lancaster University, Lancaster, UK D 0, D , D s only Branching fractions Amplitude analyses D s lifetime
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BEACH06, 2-8 July 2006, Lancaster University, Lancaster, EnglandWerner Sun, Cornell University 2 Introduction Topics covered reflect personal bias and new developments in past year or so. Branching fractions for D 0, D , D s decays: Important engineering numbers for B and B s decays. Overall normalization for |V cb |. Amplitude analyses of D 0 and D decays: Probes of strong phases. Probes of D 0 -D 0 mixing (not discussed). Lifetimes Tests of theory. Probes of D 0 -D 0 mixing (not discussed). Topics not covered (sorry!) Charmed baryons Belle’s recent observation of orbitally excited cx (2980) , cx (3077) , and cx (3077) 0 decaying to c K and c K 0 S [hep-ex/0606051]. D sJ (2317) , D sJ (2463) , and D sJ (2632)
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BEACH06, 2-8 July 2006, Lancaster University, Lancaster, EnglandWerner Sun, Cornell University 3 The Experiments B factories: BABAR & Belle E cm ~ 10.6 GeV. Copious charm production in continuum and B decays, many states available. Initial state unknown (no absolute B s). Slow pion from D tags flavor of D 0 daughter. Charm factories: CLEO-c & BES E cm ~ 3.773 GeV and above: DD pair production. Charm cross section higher, but L much lower. Known initial state, low-multiplicity, low background. Fixed target experiments: FOCUS & SELEX Huge charm cross sections, but high backgrounds. Limited 0 and K 0 S reconstruction efficiency. CDF and D0—see P. Karchin’s talk Different sources of uncertainties make for complementary analyses. Many thanks to spokespersons and analysis coordinators.
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BEACH06, 2-8 July 2006, Lancaster University, Lancaster, EnglandWerner Sun, Cornell University 4 Cabibbo-Favored Decays
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BEACH06, 2-8 July 2006, Lancaster University, Lancaster, EnglandWerner Sun, Cornell University 5 D 0 /D + Absolute Branching Fractions MARK III double tag technique using (3770) → DD, 55.8 pb -1 [PRL 95, 121801 (2005)]. Single tag (ST): n i = N DD B i i Double tag (DT) : n ij = N DD B i B j ij Independent of L and cross sections. Scale of statistical error set by sum of DT yields. Combine ST and DT yields in 2 fit for B and N DD. Many D B s measured relative to B (K + ) or B (K + + ). To be updated soon with 281 pb -1. All D 0 DT 2484 ± 51 All D + DT 1650 ± 42 DD Xi DD ji NDDNDD (2.01±0.04±0.02)x10 5 B(K+)B(K+) (3.91±0.08±0.09)% B(K+)B(K+) (14.9±0.3±0.5)% B(K++)B(K++) (8.3±0.2±0.3)% ND+D-ND+D- (1.56±0.04±0.01)x10 5 B(K++)B(K++) (9.5±0.2±0.3)% B(K++0)B(K++0) (6.0±0.2±0.2)% B(KS+)B(KS+) (1.55±0.05±0.06)% B(K0S+0)B(K0S+0) (7.2±0.2±0.4)% B(K0S+-+)B(K0S+-+) (3.2±0.1±0.2)% B(K+K+)B(K+K+) (0.97±0.04±0.04)% (D0D0)(D0D0) (3.60±0.07 +0.07 -0.05 ) nb (D+D-)(D+D-) (2.79±0.07 +0.10 -0.04 ) nb (+-)/ (00) 0.776±0.024 +0.014 -0.008 Overall C.L 25.9%
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BEACH06, 2-8 July 2006, Lancaster University, Lancaster, EnglandWerner Sun, Cornell University 6 Same basic technique as for D 0 /D +. Fall 2005: energy scan of 12 points in E cm ~ 4 GeV region (60 pb -1 ). B s use 76 pb -1, mostly taken at E cm = 4.17 GeV; use D s D s instead of D s D s . Current precision: B = 11%. B < 4% with full CLEO-c dataset. D s → is one component of K K . Previous measurements ignored f 0 (not high enough precision to matter). Now, need Dalitz analysis to disentangle contributions. D s + Absolute Branching Fractions Maximal D s + yield. Peak structure in D s D s Mode B (%) (CLEO-c) B (%) (PDG) K0SK+K0SK+ 1.28 +0.13 -0.12 ±0.071.80±0.55 K+K-+K+K-+ 4.54 +0.44 -0.42 ±0.254.3±1.2 K+K-+0K+K-+0 4.83 +0.49 -0.47 ±0.46--- ++-++- 1.02 +0.11 -0.10 ±0.051.00±0.28 PRELIMINARY All D s + DT 118 ± 12
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BEACH06, 2-8 July 2006, Lancaster University, Lancaster, EnglandWerner Sun, Cornell University 7 Inclusive D → K (*) X Probe relative strength of CF D → K (*) and CS D → K (*). 33 pb -1 near (3770). Tag one side, reconstruct K (*) on other side, subtract M BC sidebands. Mode B (%) (BES) B (%) (PDG) D 0 → K X 8.7 ± 4.0 ± 1.2 D → K X 23.2 ± 4.5 ± 3.0 D 0 → K X 2.8 ± 1.2 ± 0.4 D → K X < 6.6 (90% CL) D 0 → K X 15.3 ± 8.3 ± 1.9 D → K X 5.7 ± 5.2 ± 0.1 D 0 → K X < 3.6 (90% CL) D → K X < 20.3 (90% CL) D0 → K0/K0XD0 → K0/K0X 47.6 ± 4.8 ± 3.042 ± 5 D → K0/K0XD → K0/K0X 62.5 ± 5.6 ± 3.459 ± 7 [PLB 625, 196 (2005)] [PRELIMINARY] D0→D0→ K K signal sideband K 0 S sideband
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BEACH06, 2-8 July 2006, Lancaster University, Lancaster, EnglandWerner Sun, Cornell University 8 Inclusive D (s) → { , ’, }X Inclusive ss rates expected to be higher for D s than D 0 /D . B s help determine B s 0 production rate at (5S). CLEO-c measurements with 281 pb -1 D 0 /D and 71 pb -1 D s . Tag one side, reconstruct , ’, on other side, subtract sidebands. includes feeddown from ’. Saturated by exclusive modes for D s . B (%) ’ (%) (%) D0D0 9.4 ± 0.4 ± 0.6 2.6 ± 0.2 ± 0.2 1.0 ± 0.1 ± 0.1 DD 5.7 ± 0.5 ± 0.5 1.0 ± 0.2 ± 0.1 1.1 ± 0.1 ± 0.2 DsDs 32.0 ± 5.6 ± 4.711.9 ± 3.3 ± 1.215.1 ± 2.1 ±1.5 PRELIMINARY D s → ’X : - ’ mass difference (GeV) signal sideband
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BEACH06, 2-8 July 2006, Lancaster University, Lancaster, EnglandWerner Sun, Cornell University 9 D 0 → Three Kaons + X D 0,D 0 → K 0 S K 0 S K First observation. Two CF modes: D 0 → K 0 K 0 K K 0 K 0 K Distinguished with D tag, both observed. Assuming no contribution from CS mode K 0 K 0 K . B (K 0 S K 0 S K ) = (6.1 ± 1.1 ± 0.7) x 10 -4 No evidence for substructure. D 0 → K 0 S K 0 S K 0 S Only proceeds via W-exchange or final state interactions. B (K 0 S K 0 S K 0 S ) = (10.4 ± 1.6 ± 1.7) x 10 -4 [PDG = (9.2 ± 1.6) x 10 -4 ] No evidence for substructure. [PLB 607, 56 (2005)]
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BEACH06, 2-8 July 2006, Lancaster University, Lancaster, EnglandWerner Sun, Cornell University 10 Cabibbo-Suppressed Decays
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BEACH06, 2-8 July 2006, Lancaster University, Lancaster, EnglandWerner Sun, Cornell University 11 D 0/+ : Pionic Modes Many new B measurements, rich resonant substructure. B (10 -3 ) CLEO-cBABARBESPDG04 1.39 ± 0.04 ± 0.031.31 ± 0.27 ± 0.041.38 ± 0.05 0.79 ± 0.05 ± 0.040.84 ± 0.22 13.2 ± 0.2 ± 0.511 ± 4 < 0.35 (90% CL)--- 7.3 ± 0.1 ± 0.36.4 ± 1.5 ± 0.47.3 ± 0.5 9.9 ± 0.6 ± 0.7--- 4.1 ± 0.5 ± 0.2--- 1.25 ± 0.06 ± 0.081.22 ± 0.10 ± 0.111.33 ± 0.22 3.35 ± 0.10 ± 0.203.9 ± 1.0 ± 0.33.1 ± 0.4 4.8 ± 0.3 ± 0.4--- 11.6 ± 0.4 ± 0.7--- 1.60 ± 0.18 ± 0.171.82 ± 0.25 CLEO-c isospin analysis of : A 2 /A 0 = 0.420 ± 0.014 ± 0.010 cos = 0.062 ± 0.048 ± 0.058 Evidence for final state interactions. [PRL 96, 081802 (2006)] [hep-ex/0605044] [PLB 622, 6 (2005)]
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BEACH06, 2-8 July 2006, Lancaster University, Lancaster, EnglandWerner Sun, Cornell University 12 Substructure in D → n( + ) m( 0 ) Also search for , contributions [PRL 96, 081802 (2006)] Compare M( + - 0 ) in E = E cand E beam signal and sideband regions. D + → + + - 0 Mode B (x10 -3 ) PDG (x10 -3 ) 1.7 ± 0.5 ± 0.2--- 0.62 ± 0.14 ± 0.05--- < 0.35 (90% CL)--- < 0.26 (90% CL)--- < 1.9 (90% CL)--- 3.61 ± 0.25 ± 0.263.0 ± 0.6 < 0.34 (90% CL)---
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BEACH06, 2-8 July 2006, Lancaster University, Lancaster, EnglandWerner Sun, Cornell University 13 D 0/+ : Kaonic Modes No SU(3) triangle for KK: K 0 K 0 vanishes in SU(3) limit—contributions only from SU(3) breaking and final state interactions. B (10 -3 ) FOCUSBESCLEO-cPDG04 KKKK 4.68±0.42±0.183.90±0.12 K0K0K0K0 0.84±0.19±0.110.74±0.14 K K 2.39±0.09±0.093.6±1.5±0.42.49±0.23 K0SK0SK0SK0S 1.2±0.2±0.21.27±0.24 KKKK 6.64±1.11±0.415.7±0.5 KKKK 11.0±1.2±0.79.7±0.4±0.48.9±0.8 [PLB 610, 225 (2005)] [PLB 607, 56 (2005)] [PLB 622, 6 (2005)] [PRL 95, 121801 (2005)]
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BEACH06, 2-8 July 2006, Lancaster University, Lancaster, EnglandWerner Sun, Cornell University 14 Doubly-Cabibbo-Suppressed Decays
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BEACH06, 2-8 July 2006, Lancaster University, Lancaster, EnglandWerner Sun, Cornell University 15 D 0 Decays For D 0, DCS final state is “wrong-sign” relative to CF decay. R D = DCS/CF rate ratio ~ O(tan 4 C ) BUT, possible contribution from mixing x = M/ , y = /2 {x’,y’} are {x,y} rotated by DCS/CF relative strong phase. Phase can be measured via quantum correlations at (3770). For K , CLEO-c finds cos = 1.09 ± 0.66 [Preliminary, hep-ex/0603031] Quoted values of R D assume no mixing or CP violation. R D (10 -3 ) KK K0K0 KK Belle 3.77 ± 0.08 ± 0.052.29 ± 0.15 ± +0.13 -0.09 3.20 ± 0.18 ± +0.18 -0.13 BABAR 2.14 ± 0.08 ± 0.08 FOCUS 4.29 +0.63 -0.61 ± 0.27 CDF 4.05 ± 0.21 ± 0.11 PDG 3.62 ± 0.294.3 +1.1 -1.0 ± 0.74.2 ± 1.3 [PLB 618, 23 (2005)] [hep-ex/0605027] [PRL 96, 151801 (2006)] [PRL 95, 231801 (2005)] [hep-ex/0605046] DCS mostly K CF mostly K
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BEACH06, 2-8 July 2006, Lancaster University, Lancaster, EnglandWerner Sun, Cornell University 16 D + Decays The DCS decay D → K 0 has no CF counterpart. Recently observed by BABAR, confirmed by CLEO-c. Last uncertainty from reference B (D → K ). B (10 -4 ) BABAR [hep-ex/0605044] CLEO-c K0K0 2.46 ± 0.46 ± 0.24 ± 0.162.14 ± 0.34 ± 0.11 ± 0.07 PRELIMINARY
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BEACH06, 2-8 July 2006, Lancaster University, Lancaster, EnglandWerner Sun, Cornell University 17 Amplitude Analyses
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BEACH06, 2-8 July 2006, Lancaster University, Lancaster, EnglandWerner Sun, Cornell University 18 D → Dalitz Analyses Decay amplitudes parametrized as sum of interfering Breit-Wigners. D → 0 (CLEO II.V) [PRD 72, 031102 (2005)] Also used K-matrix parametrization of S-wave—no evidence found. D → (CLEO-c) Results agree with E791 [PRL 86, 770 (2001)] and FOCUS [PLB 585, 200 (2004)] In particular, fit fraction = (41.8 ± 1.4 ± 2.5)% Parametrized by complex pole: A = 1/[ (0.47-0.22i)GeV 2 – m 2 ( )]. PRELIMINARY
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BEACH06, 2-8 July 2006, Lancaster University, Lancaster, EnglandWerner Sun, Cornell University 19 D → KK ( ) Dalitz Analyses D → K K 0 (CLEO III) [hep-ex/0606045, submitted to PRD] K and K strong phase needed to extraction CKM parameter / 3 [Grossman, Ligeti, Soffer, PRD 67, 071301 (2003)]. Measured to be (332 ± 8 ± 11) o → nearly maximal destructive interference. r D = 0.52 ± 0.05 ± 0.04 D → K K (FOCUS) [PLB 610, 225 (2005)] Dominated by AP: K 1 (1270) K (33%), K 1 (1400) K (22%), VV: 0 (29%). In K K spectrum, line shape distorted by f 0 (980).
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BEACH06, 2-8 July 2006, Lancaster University, Lancaster, EnglandWerner Sun, Cornell University 20 D + → K 0 S,L + CF/DCS interference switches sign between K 0 L and K 0 S → B asymmetry. Could be O(10%) [Bigi & Yamamoto, PLB 349 (1995) 363-366]. Depends on relative strong phases between amplitudes. Reconstruct K 0 s + K 0 L inclusively in missing mass recoiling against +. B (D + → K 0 S + ) + B (D + → K 0 L + ) = (3.06 ± 0.06 ± 0.16)% Asymmetry = (K 0 L K 0 S )/(K 0 L + K 0 S ) = 0.01 ± 0.04 ± 0.07 c d w+w+ s d u d D+D+ ++ K0K0 Cabibbo-favored c d s d u d D+D+ ++ K0K0 w+w+ Color-suppressed c d d s u d D+D+ ++ K0K0 w+w+ DCS, color-suppressed D + → K 0 + (3879 ± 71 events) D + → + D + → 0 + (176 ± 13 events) (Missing mass) 2 (GeV 2 ) DATA PRELIMINARY D + → + (487 ± 38 events) S,L tag side signal side inferred from missing mass fully reconstructed
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BEACH06, 2-8 July 2006, Lancaster University, Lancaster, EnglandWerner Sun, Cornell University 21 D s + Lifetime Need lifetimes to convert B s into partial widths. Extract CKM matrix elements. Test isospin invariance. FOCUS dominates D 0, D +, D s lifetimes. [D CP lifetimes also limit mixing.] New FOCUS measurement for D s [PRL 95, 052003 (2005)]. (D s )/ (D ) = 1.239 ± 0.017 Probes weak annihilation contribution. (fs)FOCUSPDG04 (Ds)(Ds) 507.4 ± 5.5 ± 5.1490 ± 9 D s → Ds → KKDs → KK Ds → KKDs → KK
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BEACH06, 2-8 July 2006, Lancaster University, Lancaster, EnglandWerner Sun, Cornell University 22 Summary & Outlook Much recent activity in study of charm hadronic decays. High-precision branching fractions. Complex resonant substructure in multibody decays. Interesting interference effects. Much more to come: B factories and Tevatron are still collecting large incoherent charm datasets. CLEO-c runs through March 2008; will significantly increase coherent charm datasets. BES III to turn on in the next few years; expected to collect 25x CLEO-c sample! Next generation fixed target experiments: LHCb & PANDA. Charm physics will continue to be a rich area of exploration!
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BEACH06, 2-8 July 2006, Lancaster University, Lancaster, EnglandWerner Sun, Cornell University 23 Backup Slides
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BEACH06, 2-8 July 2006, Lancaster University, Lancaster, EnglandWerner Sun, Cornell University 24 Effect of Quantum Correlations |D 1,2 > = p|D 0 > ± q|D 0 > Because of quantum correlation between D 0 and D 0, not all final states allowed. This affects: total rate apparent branching fractions Two entangled causes: Interf. between CF and DCSD. D mixing: single tag rates depend on y = ( 2 - 1 )/2 . Semileptonic decays tag flavor unambiguously (if no mixing) If one D is SL, the other D decays as if isolated/incoherent. Exploit coherence to probe DCSD and mixing—shows up in time- integrated rates. e e * D 0 D 0 C = 1 KK KK KK KK KK KK KK K l CP+ K l CP- K l K l K l CP+CP- CP+ CP- interference forbidden by CP conservation forbidden in absence of mixing maximal constructive interference
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BEACH06, 2-8 July 2006, Lancaster University, Lancaster, EnglandWerner Sun, Cornell University 25 Introduction In the Standard Model, D mixing strongly suppressed (CKM and GIM). Previous searches: Double semileptonic rates give R M. Time-dependent K : x and y rotated by Current analysis: Uses time-independent yields. Sensitive to y at first order. No sensitivity to p/q≠1; neglect CPV in decay. References: Goldhaber, Rosner: PRD 15, 1254 (1977). Xing: PRD 55, 196 (1997). Gronau, Grossman, Rosner: hep-ph/0103110. Atwood, Petrov: PRD 71, 054032 (2005). Asner, Sun: hep-ph/0507238. Definition Current knowledge y ( 2 - 1 )/2 = B (CP+) B (CP-) B f r f z f 0.008 ± 0.005 x (M 2 -M 1 )/ sensitive to NP x’ < 0.018 RMRM (x 2 +y 2 )/2< ~1 x 10 -3 r K DCS-to-CF rel. amplitude 0.061 ± 0.001 K DCS-to-CF relative phase (weak) + ? (strong) z 2cos None w 2sin None
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BEACH06, 2-8 July 2006, Lancaster University, Lancaster, EnglandWerner Sun, Cornell University 26 Single and Double Tag Rates Hadronic rates (flavored and CP eigenstates) depend on mixing/DCSD. Semileptonic modes (r = = 0) resolve mixing and DCSD. Rate enhancement factors, to leading order in x, y and r 2 : With C=+1 D 0 D 0 at higher energy, sensitivity to wx at first order. Not much info if w is small. fl+l+CP+CP- fR M /r 2 f1+r 2 (2-z 2 ) l-l-11 CP+1+rz10 CP-1-rz120 X1+rzy11-y1+y DD Single tag: X i DD Double tag: j i
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BEACH06, 2-8 July 2006, Lancaster University, Lancaster, EnglandWerner Sun, Cornell University 27 Results Fit inputs: 6 ST, 14 hadronic DT, 10 semileptonic DT, efficiencies, crossfeeds, background branching fractions and efficiencies. 2 = 17.0 for 19 d.o.f. (C.L. = 59%). ParameterValuePDG or CLEO-c NDDNDD (1.09 ± 0.04 ± ?)x10 6 (1.01 ± 0.02)x10 6 y-0.057 ± 0.066 ± ? r2r2 -0.028 ± 0.069 ± ? (3.74 ± 0.18)x10 -3 PDG + Belle + FOCUS rz0.130 ± 0.082 ± ? RMRM (1.74 ± 1.47 ± ?)x10 -3 < ~1x10 -3 B (K ) (3.80 ± 0.29 ± ?)%(3.91 ± 0.12)% B(KK)B(KK)(0.357 ± 0.029 ± ?)%(0.389 ± 0.012)% B()B() (0.125 ± 0.011 ± ?)%(0.138 ± 0.005)% B(K0S00)B(K0S00) (0.932 ± 0.087 ± ?)%(0.89 ± 0.41)% B(K0S0)B(K0S0) (1.27 ± 0.09 ± ?)%(1.55 ± 0.12)% B (X e ) (6.21 ± 0.42 ± ?)%(6.87 ± 0.28)% PRELIMINARY Fitted r 2 unphysical. If constrain to WA, cos = 1.09 ± 0.66 ± ?. Limit on C=+1 contamination: Fit each yield to sum of C=-1 & C=+1 contribs. Include CP+/CP+ and CP-/CP- DTs in fit. No significant shifts in fit parameters. C=+1 fraction = 0.06 ± 0.05 ± ?. Some branching fracs competitive with PDG. Uncertainties are statistical only
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