Sep. 29, 2006 Henry Band - U. of Wisconsin 1 Hadronic Charm Decays From B Factories Henry Band University of Wisconsin 11th International Conference on B Physics at Hadron Machines Oxford, Sept , 2006

Sep. 29, 2006 Henry Band - U. of Wisconsin 2 Talk Outline  Strange charmed mesons D sJ (2860) + D sJ (2700)+ D s2 (2573) + D s1 (2536) + D s1 (2460) + D s0 * (2317) + D s * (2112) +  Abs. Branching Fractions D s + → K + K -  + D s + →  +  Branching Fractions D + →  +  0 D + → K +  0 D 0 →  -  +  0 D 0 → K - K +  0  Charm Baryons   c (2940)   Λ c (2880) +   c *  Ξ c (2980) +  Ξ c (3077) +

Sep. 29, 2006 Henry Band - U. of Wisconsin BaBar and Belle  e + e -   cc continuum  1.3 nb Off and on peak  (4S) 30% more cc than bb  b  c Cabbibo favored Peak luminosity 1.21  cm –2 s –1 Integrated luminosity 390 fb –1 Peak luminosity 1.65  cm –2 s –1 Integrated luminosity 630 fb –1 Sep.   ab-1 integrated flux combined B Factories C

Sep. 29, 2006 Henry Band - U. of Wisconsin 4 D s family mesons  Observation by BaBar, Cleo, and Belle of D sj (2317) and D sj (2460) at lower masses than expected by HQS theories raised questions about cs meson spectroscopy  D s mesons or exotics (4 quarks)?  Gather more info Masses Width Decay modes Branching fractions Other decay modes New states D sJ * (2317) D sJ (2460) DsDs Ds*Ds* D s1 (2536) D s2 (2573) Q q

Sep. 29, 2006 Henry Band - U. of Wisconsin 5 Spin Analysis D sJ * (2317) D sJ (2460) DsDs Ds*Ds* D s1 (2536) D s2 (2573) Q q J = 0:  2 /d.o.f = 3/8 J = 1:  2 /d.o.f = 38/8 J P = 0 + D sJ (2317) → D s π 0 Belle-CONF-0461 (2004) 274M BB J = 1:  2 /d.o.f = 4/8 J = 2:  2 /d.o.f = 89/8 J P = 1 + D sJ (2460) → D s γ B decays

Sep. 29, 2006 Henry Band - U. of Wisconsin 6 Survey of Decays to D s  Final States  Select D s → K + K -  +  Require   K + K - or K*(892 )  K -  + p*> 2.2 GeV  Combine with , K, ,  0  Tighter cuts on p* and kinematics to select intermediate states (D s (*), D sJ (2317))  Subtract D s X bkg using D s mass sidebands  Fit mass spectrum signal  Breit-Wigner  resolution Combinatorial background include pdfs for possible reflections from other  cs states No cut Cuts on intermediate states sidebands signal ~ D s + Hep-ex

Sep. 29, 2006 Henry Band - U. of Wisconsin 7  D s   D s * (2112), D s1 (2460)  D s  - Combine D s with  ‘s > 150 MeV/c  Raise E  > 500 MeV/c  Fit signal peak + sum oBkgd oD s0 * (2317)  D s +     ) oD s1 (2460)  D s * (2112) +     ) 232 fb -1 D s1 (2460) +  D s +  D s sidebands N=920±60 Bkgd. subtracted Hep-ex D s +  invariant mass (GeV/c 2 ) D s * (2112) + N= 75,000

Sep. 29, 2006 Henry Band - U. of Wisconsin 8 D s     D s0 * (2317) D s +  0 invariant mass (GeV/c 2 )  Combine D s with 2  ‘s consistent with    Fit D s +  0 mass spectrum to  D s0 * (2317)  D s +    D s1 (2460)  D s +    D s * (2112)  D s +    Reflections from  D s * (2112)  D s +  (+  )  D s1 (2460)  D s * (2112) +   (-  )  Combinatorial bkgd 232 fb -1 D s0 * (2317) + Hep-ex N= 26,500

Sep. 29, 2006 Henry Band - U. of Wisconsin 9 D s    D s      D s   D s1 (2460)  D s  0   Assume  D s1 (2460)  D s *(2112) +  0  Require 2092< m(D s  MeV/c  Fit signal + reflections  D s  0  0 no signal  D s  no signal 232 fb -1 D s sidebands Light shade: D s * (2112) reflection Dark shade: D sJ * (2317) reflection N=560±40 Preliminary Hep-ex D s  0  D s1 (2460) + D s +  0  invariant mass (GeV/c 2 )

Sep. 29, 2006 Henry Band - U. of Wisconsin 10 D s  ±, D s      D s1 (2460) + D s1 (2536) +  Look for isospin partners D s +  - : no signal D s +  + : no signal  D s  +  - :  no D sJ * (2317)  Strong signals  D s1 (2460) +  D s1 (2536) + D s  +  fb -1 D s1 (2536) + D sJ (2460) + Hep-ex D s +  - D s +  + D s +  +   invariant mass (GeV/c 2 )

Sep. 29, 2006 Henry Band - U. of Wisconsin 11 D 0 K +, D + K 0 s - D s2 (2573) +, D sJ (2860) +, X(2690) +  Look for new states in continuum above DK mass  Cuts on D 0(+) and K s reconstructed masses a) D 0  K -  + (950,000) b) D 0  K -  +  0 (790,000) c) D +  K -  +  + (430,000) Hep-ex D+D+ D0D0 D0D0 232 fb -1

Sep. 29, 2006 Henry Band - U. of Wisconsin 12 New States - D sJ (2860) +, X(2690) + (?)  New resonance at 2.86 GeV/c 2  Broad state at 2.69 GeV/c 2 Hep-ex Combined modes bkgd subtracted D sJ (2860) + D s2 (2573) + invariant mass (GeV/c 2 ) D 0  K -  + D 0  K -  +  0 D +  K -  +  +

Sep. 29, 2006 Henry Band - U. of Wisconsin 13 D sj Production in B decays D sj production in several modes  BELLE has observed D sj production in several modes  B  DD sj (2317) or DD sj (2460) Established spinsEstablished spins  B  K - D sj (2317) or K - D sj (2460)  B + → D 0 D 0 K + S = 399 ± 40 S/B ~ 0.3 Dalitz plot and mass projections - different from 3-body phase space Belle-CONF-0643 (2006) 447M BB __ _ _ _ +

Sep. 29, 2006 Henry Band - U. of Wisconsin 14 B+→D0D0K+B+→D0D0K+B+→D0D0K+B+→D0D0K+ Contributions from several sources Is D sJ (2700) = X(2690) ? Belle-CONF-0643 (2006) 447M BB ■ B + →D 0 D sJ (2700) ■ B + →ψ(3770)K + ■ B + →ψ(4160)K + ■ B + →D 0 D 0 K + NR ■ threshold comp J=0  2 /ndf = 185/5 J=1  2 /ndf = 7/5 J=2  2 /ndf = 250/5 J P = 1 - ■ ψ(4160) reflection Spin Analysis

Sep. 29, 2006 Henry Band - U. of Wisconsin 15 D *+ K 0 s - D s1 (2536) +  D *+  D 0  + D 0  K -  + D 0  K -  -  +  +  Charged tracks = good mass resolution  Low Q – close to threshold Hep-ex First width measurement !

Sep. 29, 2006 Henry Band - U. of Wisconsin 16 D sJ (2700) m= 2715 ± Mev/c 2  = 115 ± MeV /c 2

Sep. 29, 2006 Henry Band - U. of Wisconsin 17 Branching Fraction D s + → K + K -  +  Identify two body D s1 D s *  Reconstruct 1 side (D s1 (2536) or D s *)  Recoil mass is M recoil = √((√s-E (D s1 )) 2 - p 2 (D s1 ))  Measure D s * peak or D s1 → Ds → Ds  → K + K -  + → D* 0 K + → D* + K s 0

Sep. 29, 2006 Henry Band - U. of Wisconsin 18  Need further BKgd suppression so use cascade decays on both sides (not just tag)  Require additional  with D s1 + tag (D s * + → D s +   Or K with D* s tag   recoil (D s1  ) = M recoil (D s1 ) - M recoil (D s1  )  B(D s + → K + K -  + ) = 4.1 ± 0.4 ± 0.4%  PDG ± 0.9% Branching Fraction D s + → K + K -  + D* s tag D s1 tag Belle-CONF-0612 (2006) D s * + → D s +    D s * + → D s +     recoil (D s *K) GeV/c   recoil (D s1  ) GeV/c 

Sep. 29, 2006 Henry Band - U. of Wisconsin 19  BB sample with one B fully reconstructed  Other B  D ( * )+,0 X Observe D s + and D sJ (2460) signals in the recoil mass, m X Abs. BF’s for D s + (   + ) and D sJ (2460) e-e-e-e- D*D*D*D*  e+e+e+e+ B reco B signal D* X Hep-ex Fitting the different modes and combining with previously measured branching ratios PDG 

Sep. 29, 2006 Henry Band - U. of Wisconsin 20 Branching Fractions - D + →  +  0, K +  0  Improved BF measurements benefit D mixing analyses  Measure BF relative to D + → K -  +  +  Reconstruct D + → h +  0 Require D* + → D +  0 p*(D*) > 2.9 GeV/c Use  m sidebands to estimate peaking background  Efficiencies % Sideband region Signal region MC Peaking bkg. from sideband fit MC

Sep. 29, 2006 Henry Band - U. of Wisconsin 21 Fits  Yield from un-binned maximum likelihood fits D + →  +  0  D + →K +  0  D + →K -  +  +   Using BF(D +  K -  +  + ) = (9.4  0.3)x10 -2 from CLEO-C & PDG 124 fb -1 First Observation >6.5  D+→K+0D+→K+0 D+→+0D+→+0 ref: D + →K -  +  + BF(D +  +  0 )/BF(D +  K -  +  + ) = BF(D +  K +  0 )/BF(D +  K -  +  + ) = BF(D +  +  0 )=( 1.25  0.10  0.09  0.04(ref) )  BF(D +  K +  0 )=( 2.52  0.47  0.25  0.08(ref) )  Hep-ex

Sep. 29, 2006 Henry Band - U. of Wisconsin 22  Cabibbo suppressed 2 body decays of D 0 show anomalous suppression of D 0   -  + versus D 0  K - K + (~1/3)  Three body decays are poorly measured  Reconstruct D *+ → D 0  +  m = m(D *+ ) - m(D 0 ) Fit K -  +  0 reflection in the  -  +  0 and K - K +  0 distributions  Recover non-uniform reconstruction efficiency weighting events with: W = 1/efficiency  no assumptions on Dalitz plot structure Branching Fractions - D 0 →  -  +  0, K - K +  0 D 0 → K -  +  0 D0→ -+0D0→ -+0 D 0 → K - K +  0 Belle  ±  ±  Hep-ex Belle-CONF-0608 (2006) 232 fb - 1

Sep. 29, 2006 Henry Band - U. of Wisconsin 23 Charm Baryon States J P =3/2 + (L=0) J P =1/2 + (L=0) Strangeness Charm Isospin  Most C = 1 baryon ground states have been observed (except  *c)  L > 0 states now being seen  C = 2 QQq candidates observed by SELEX  (ccd)+   c + K -  +  (ccu)++   c + K -      cc +  p D + K - C= 1

Sep. 29, 2006 Henry Band - U. of Wisconsin 24  c (2940)   p D 0  Search in continuum cc pD 0 modes (D 0  K -    K -       )  Observe previously reported Λ c (2880) + (was observed in  c     by CLEO ) M = ±0.1±0.5 MeV/c 2 Γ = 5.8±1.5±1.1 MeV  New state Λ c (2940) + M = ±1.3±1.0 MeV/c 2 Γ = 17.5±5.2±5.9 MeV Confirmed by BELLE in Λ c -->  c  First example of a charm baryon decay to a charm meson  No isospin partners seen in D + p so both Λ c not  c Λ c (2880) + Λ c (2940) + Wrong sign D 0 p Hep-ex fb -1

Sep. 29, 2006 Henry Band - U. of Wisconsin 25 First Observation of  c * (css)   c   Reconstruct  c 0 → a)  -  + (  - →  K - ) 156 +/- 15 events b)  -  +  0 (  - →  K - ) 92 +/- 26 c)  -  +  -  + (  - →  K - ) 23 +/- 10 d)  -  -  +  +   - →  K - ) 34 +/- 15  Combine with      MeV)  Plot M(  c   – M  c     + M  c    PDG  Combined yield 105 ± 21 ± 6    M = M(  c   – M  c     = 70.8 ± 1.0 ± 1.1 MeV  Theoretical predictions 50 – 73 MeV Hep-ex fb -1 M(  c   – M  c     + M  c    PDG GeV/c 2

Sep. 29, 2006 Henry Band - U. of Wisconsin 26 Search for Doubly Charmed Baryons  SELEX reported evidence for  cc in  c + K -   + (  + ), D + p K -  Babar has looked for similar decays  cc +(+)   c + K -  + (  + )  c c +(+)   c 0  + (  + )  Belle searched  cc +(+)   c + K -  +  No evidence despite >10 6  c in B factories SELEX(1630  c ) Λ c + K – π + p*> 0 GeV/c Λ c + K – π + p*>2.3 GeV/c Λ c + K – π + π + p*>2.3 GeV/c Λ c + K – π + π + p*> 0 GeV/c Hep-ex fb -1

Sep. 29, 2006 Henry Band - U. of Wisconsin 27 Observation of Ξ c (2980) + and Ξ c (3077) +  Look for decays to Λ c + K - π +  No peaks in the wrong sign distribution  No peaks in the side band  Also seen in the isospin partners Λ c + →pK - π + Mass(Λ c + K - π + ) Λ c + →pK + π - Mass(Λ c + K S π - ) hep-ex/ , Ξ c (2980) and Ξ c (3077)  excited charm strange baryons. Belle Hep-ex

Sep. 29, 2006 Henry Band - U. of Wisconsin 28 Summary  Large B factory charm samples still producing new charm meson and baryon discoveries D sJ (2860) + D sJ (2700)+  Plus refined masses, widths, BFs on previously discovered states  But no double charm  Can expect much more in the coming years   c (2940)   Λ c (2880) +   c *  Ξ c (2980) +  Ξ c (3077) +