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JOLANTA BRODZICKA

Doubly charmed B decays. B  D(*) D(*) K. JOLANTA BRODZICKA. ICPV Meeting December 12, 2002. Institute of Nuclear Physics, Krakow. Plan. b  c c s transition “ wrong-sign” D production physics motivations analysis details

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JOLANTA BRODZICKA

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  1. Doubly charmed B decays B  D(*) D(*) K JOLANTA BRODZICKA ICPV Meeting December 12, 2002 Institute of Nuclear Physics, Krakow

  2. Plan • b  c c stransition “wrong-sign” D production • physics motivations • analysis details • (very) preliminary results ( for ~78 fb-1 ) • future plan JOLANTA BRODZICKA B  D(*) D(*) K December 12, 2002

  3. Mechanisms of BD(*)D(*)K decays phase-space suppressed b  cW - c c s + dd (uu) pair creation ( I ) through external W-emission amplitudes B+ D(*)0 D(*)+ K0 B0 D(*)- D(*)0 K+ ( II ) internal W-emission amplitudes (color-suppressed) B+ D(*)+ D(*)- K+ B0 D(*)0 D(*)0 K0 ( III ) external +internal W-emission amplitudes B+ D(*)0 D(*)0 K+ B0 D(*)- D(*)+ K0 22 decay modes + c.c JOLANTA BRODZICKA B  D(*) D(*) K December 12, 2002

  4. Physics motivations • charm counting puzzle B  D(*) D(*) K : significant (~1/2) contribution to b ccs transitions precise BF’s measurements needed • B0 D(*) D(*) K0Sto probe both sin2 and cos2 small penguin pollution expected • possible resonant contribution cc-bar states ((3770), (4040), …) upper-vertex D(*)K system vector-dominance model 1+ 1- particles easily produced from W-vertex (because of V-A)  quasi-2-body B decays rather than 3-body ( e.g high BF`s for B   D(*), a1 (1260) D(*), Ds*D ) expecteddecays to orbitally-excited Ds mesons followed by Ds** D(*)K p-wave excited (c s) states : according to HQS 2 doublets : jP = 1/2+ JP = (0 + , 1+ ) D*s0D*s1 not seen, wide jP = 3/2+ JP = (1 + , 2+ ) probably Ds1±(2536) DsJ ±(2573) narrow JOLANTA BRODZICKA B  D(*) D(*) K December 12, 2002

  5. Analysis details • at least 5 good tracks : abs(IP_dz)< 5cm abs(IP_dr)< 0.4cm • R2< 0.3 • K± : P(K/) > 0.6± : P(/K) > 0.6 electron veto: el_id < 0.95 • K0Sabs( M(+ -) - MKs ) < 15 MeV only good_Ks • 0 E > 50 MeV abs( M( ) -M0 ) < 15MeV • D±, D0 and D*±, D*0 reconstruction ( N(D)>1 : p(D) < 2 GeV ) • B±, B0 reconstruction : all possible (22 + c.c) physical combinationsD(*)D(*)K B vertex fit: with IP and B lifetime constraints “shape” cuts: abs(cosTHR)<0.8 abs(cosPROD)<0.8 Mbc > 5.2GeV -0.40 < E < 0.35 GeV JOLANTA BRODZICKA B  D(*) D(*) K December 12, 2002

  6. D(*) plots for ~ 11fb-1 (exp17) D0reconstruction for skimmed sample (with DDK candidate ) S=93K S=22K S=101K BF ~ 28% • vertex fit (refit 0 ) • M (DREC) cut: ± 20MeV • (D0 K0 : ± 50MeV) • constraint_mass fit D0 K D0 K3 D0 K0 (doesn`t applied for these plots) S=18K S=10K S=4K D0 KsKK D0 Ks D0 KK JOLANTA BRODZICKA B  D(*) D(*) K December 12, 2002

  7. D(*) plots for ~ 11fb-1 (exp17) D± reconstruction S=59K S=6.5K BF ~ 15% • reconstruction procedure • like in D0 case D±Ks D±K S=1.7K S=4.4K S=10K D±KsK D±KK D±Ks0 D± JOLANTA BRODZICKA B  D(*) D(*) K December 12, 2002

  8. D(*) plots for ~ 11fb-1 (exp17) D*± reconstruction S=6K S=9K S=9.5K D*±  D0± BF ~ 68% (D*±  D± 0hopeless ) • slow_ ID: P(/K) > 0.1 • vertex fit • (constraints :IP, B) • abs(M(D*)-M(D)-mPDG)< 2.5MeV D0 K D0 K3 D0 K0 S=1.5K S=0.8K S=0.25K D0 KsKK D0 KK D0 Ks JOLANTA BRODZICKA B  D(*) D(*) K December 12, 2002

  9. D(*) plots for ~ 11fb-1 (exp17) D*0 reconstruction • vertex fit • (constraints :IP, B) • refit 0 (vtx_constraint) • abs(M(D*)-M(D)-mPDG)< 5MeV D*0  D00 BF ~ 62% S=1.5K S=0.4K S=3.5K D0 Ks D0 K0 D0 K JOLANTA BRODZICKA B  D(*) D(*) K December 12, 2002

  10. Multi-candidates events treatment • more than 1 candidates in the same B sub-mode • multi D(*) candidates per event • D(*)D(*) combinations with different K`s ~3. B cand per event ( all sub-modes ) D, D* probabilities (LR): S(MD) S(MD), B(MD) parameterization from MD fit LR_D (MD) = + S(MD) B(MD) S(MD*) S(MD*), B(MD*) parameterization from MD*fit LR_D*(MD*) = + S(MD*) B(MD*) JOLANTA BRODZICKA B  D(*) D(*) K December 12, 2002

  11. Choice of the best B candidate B probability (LR_B) ( for each B decay sub-mode separately ) LR_B = LR_D(*) × LR_D(*) • best B candidate : with max LR_B • equal LR_B case ( B`s differ only in K ) : • larger K±_ID or better K0S mass candidate chosen S/(S+B) choice method “combines” both criteria: (M-MPDG)/ and S/B ratio JOLANTA BRODZICKA B  D(*) D(*) K December 12, 2002

  12. LR_B cut efficiency LR_B cut: good for background reduction and s /b ratio improvement Background reduction (DATA) all Efficiency reduction (signal MC ) LR_D1 * LR_D2 cut LR_D1 * LR_D2 cut Background: B±  D0 D0B K± sideband Signal MC: B±  D0 D0B K± for all D0D0B combinations JOLANTA BRODZICKA B  D(*) D(*) K December 12, 2002

  13. comb. bckg B±  D0 D0B K± D0, D0  K phase space N/20MeV MASS_D0D0B for signal-box events E Mbc vs. E Mbc Mbc Mbc  lost 2 lost S=16±4 eff~11% S=87±10 S=157±12 JOLANTA BRODZICKA B  D(*) D(*) K December 12, 2002

  14. B±  D0 D0B K±  lost Mbc Mbc Mbc 2 lost E LR_B cut 0.05 S=258±20 S=557±28 S=36±17 0.1 S=16±5 S=152±14 S=273±17 S=9±12 S=86±10 S=161±12 0.2 JOLANTA BRODZICKA B  D(*) D(*) K December 12, 2002

  15. LR_B > 0.02 B±  D+ D- K± S=28±7 Mbc E S=45±11 Mbc  lost JOLANTA BRODZICKA B  D(*) D(*) K December 12, 2002

  16. B0  D0 D- K+ LR_B > 0.02 S=40±8 Mbc E S=161±16 S=144±16 Mbc Mbc 2 lost  lost JOLANTA BRODZICKA B  D(*) D(*) K December 12, 2002

  17. B0  D0 D0B Ks (color suppressed channel ) LR_B > 0.01 E S=3±3 S=62±10 S=104±14 Mbc Mbc Mbc  lost 2 lost JOLANTA BRODZICKA B  D(*) D(*) K December 12, 2002

  18. LR_B > 0.005 B0  D*± D0 K± Mbc vs. E E S=47±7 S=137±12 Mbc Mbc  lost JOLANTA BRODZICKA B  D(*) D(*) K December 12, 2002

  19. B0  D*± D0 Ks LR_B > 0.001 Mbc vs. E E S=12±4 S=37±6 Mbc Mbc  lost JOLANTA BRODZICKA B  D(*) D(*) K December 12, 2002

  20. LR_B > 0.002 B0  D*0 D- K+ Mbc vs. E E Mbc Mbc  lost S=25±6 S=48±10 JOLANTA BRODZICKA B  D(*) D(*) K December 12, 2002

  21. LR_B > 0.01 B±  D*0 D0 K± for signal-box events for lost -pion box events N/40MeV MASS_D*K MASS_D*K D*0K+ D*0K- E right flavor comb. wrong flavor comb. D*0K+ D*0K- S=42±9 S=98±13 Mbc Mbc  lost JOLANTA BRODZICKA B  D(*) D(*) K December 12, 2002

  22. LR_B > 0.0 B0  D*±D*0 K± S=18±5 Mbc E JOLANTA BRODZICKA B  D(*) D(*) K December 12, 2002

  23. Future Plan • more D(*)D(*)K channels will be analyzed • more attention for resonant structure exploration • the stuff for 2-dim likelihood fits • MC studies for background investigation • BF’s determination • incorporate D(*)D(*)K* channels JOLANTA BRODZICKA B  D(*) D(*) K December 12, 2002

  24. LR_D*± vs. M plots LR_D0 vs. D_mass plots D0 K D0 K3 D0 K0 D0 Ks D0 KK D0 KsKK JOLANTA BRODZICKA B  D(*) D(*) K December 12, 2002

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