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Analysis work by: Marina Artuso Rachid Ayad Sheldon Stone Jianchun Wang

Jianchun Wang CLEO Physicsfest 06/12/00. Study of B D ( * )  -. Analysis work by: Marina Artuso Rachid Ayad Sheldon Stone Jianchun Wang. Introduction. Motivation: To understand hadronic B decays The measured hadronic B decay modes  10 - 12 % D (*) ( n p) - studied with n=1,2,3

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Analysis work by: Marina Artuso Rachid Ayad Sheldon Stone Jianchun Wang

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  1. Jianchun Wang CLEO Physicsfest 06/12/00 Study of BD(*)- Analysis work by: Marina Artuso Rachid Ayad Sheldon Stone Jianchun Wang

  2. Introduction Motivation: • To understand hadronic B decays • The measured hadronic B decay modes  10 - 12 % • D(*)(np)- studied with n=1,2,3 • Average charge multiplicity in hadronic B decays  5.3 Outline: • Summarize and update the results of D*(4p)- , D*- • Reconstruction of B  D- • The - resonance at 1420 MeV (A-) • Spin parity study of A- • Discussions and results Jianchun (JC) Wang

  3. B( BD*(4)- ) B ( B  D*(4)- ) : B  D*+pp+p-p- ( 1.72  0.14  0.24 ) % D*pp+p-p-( 1.80  0.24  0.25 ) % D*+wp- ( 0.29  0.03  0.04 ) % D*wp- ( 0.45  0.10  0.07 ) % D* reconstructed in channels : D*+ Dp+ (D K-p+, K-pp+, K-p+p+p-) D* Dp(D K-p+) Jianchun (JC) Wang

  4. D*+wp- D*wp- Breit-Wigner: Mass = 1432±37  = 376±47MeV Breit-Wigner: Mass = 1367±75  = 439±135MeV The wp- Mass Distribution Possible wp- resonance(A) at 141933, =38244 MeV Jianchun (JC) Wang

  5. D*+(wp)- Angular Distributions • Only D*+(wp)- modes shown, efficiency corrected • Best fitGL/G = 0.630.09(D*+), 0.100.09(w) • Spin 0 c2/ndof = 3.5(cosqD*), 22 (cosqw)  Ruled out Jianchun (JC) Wang

  6. B  Dwp-Reconstruction Fight against high background !!! • D:D K-p+, D+  K-p+p+ • Track: Good track, dE/dX consistency • Photon:Good barrel • °:Mass constraint • :Dalitz selection ( r < 0.7 ) • Event: R2 < 0.3 • B: Beam energy constraint, |cosB| < 0.5 Jianchun (JC) Wang

  7. Dwp- D+wp- 8814 9118 The Dwp-Final State Signal: |DE|<2s (18MeV) Sideband: 3s<|DE|<7s Jianchun (JC) Wang

  8. The w Side bands • The w side bands: 3s < |Mppp-Mw| < 5s • Only Dwp- channel shown Jianchun (JC) Wang

  9. B (B Dwp-) • Efficiency dependence on Mwp and decay angles considered (small) • B (B- Dwp-) = (0.410.070.04)% B (B D+wp-) = (0.280.050.03)% • Systematic errors ( ~ 10%) • 5.4% for p • 2.2% per charged track • 5.5% on background shape • Miscellaneous Jianchun (JC) Wang

  10. The wp- Mass Distribution Breit-Wigner: Mass = 141543 =419110 MeV • Modes Dwp-and D+wp- combined (179 events) • Consistent with D*wp result • Select (1.1-1.7 GeV) for angular study (104 events) Jianchun (JC) Wang

  11. Angular Distributions qA: Angle between win A- frame and A- boost direction qw: Angle between normal of w decay plane to w boost c: Angle between planes of A- decay and w decay B  D A- A- w p- w p p+ p- Jianchun (JC) Wang

  12. Angular Distributions B  D A- A- w p- w pp+ p- spin 0 0 JJ 1 0 1 0 0 0 helicity 0 0 0 0 00 0 0 Jianchun (JC) Wang

  13. Angular dependent efficiency Slightly dependent, correction made Jianchun (JC) Wang

  14. The Angular Distributions For 1+and 2-,the longitudinal ratio a0 (GL/G) is floating Jianchun (JC) Wang

  15. The c2 of Angular Fit Remind: c2 / ndof= 1.040 % Jianchun (JC) Wang

  16. Parameters of A- • Simple Breit-Wigner fit • Systematic error from background shape: 19 MeV for mass, 32 MeV for width • Spin-parity: JP = 1- Jianchun (JC) Wang

  17. Nature of A- • Clegg & Donnachie: (t(4p)n, e+e-p+p-, p+p+p-p-) Two 1- states: (146325, 31162) & (173030, 400100) mixed with non-qq, only lighter one decays to wp • Godfrey & Isgur: First radial excited r at 1450 MeV, G=320 MeV, B (wp)=39% • CLEO t(wp)n: spin-parity 1- established in the same region, mass and width are model dependent • Natural explanation: We observe r(1450) (AKA r) for first time in B decays Jianchun (JC) Wang

  18. B ( BD(*)(4)- ) • r dominates the final state • G(BD) / G(BD) = 1.040.210.06 G(BD) / G(BD) = 1.100.310.06 G(BD) / G(BD) = 1.060.170.04 consistent with Heavy Quark Symmetry prediction ( ratio  1 ) • With B (wp)=39%,G(BD(*)) ~ G(BD(*)) Jianchun (JC) Wang

  19. Factorization GL/G (BD+h) = GL/G (BD+ln)|q2=mh2 • GL/G (BD+ ) measurement: 63 ± 9 % • No GL/G (BD+ln)|q2=mh2measurement • Prediction (ISGW,WSB,HQET): 66.9% - 72.6% G(BD+h) / dG/dq2(BD+ln)|q2=mh2= 6p2c12fh2 |Vud|2 • Measurement: f2 B (wp) = 0.011 ± 0.003 GeV2 • Godfrey & Isgur predict: f = 80MeV, B (wp)=39% • B (wp) = 39% f = 167 ± 23MeV Jianchun (JC) Wang

  20. Summary • We measured B ( BD*(4p)-, D(*)wp- ) • We observed wp-enhancement at 1418±26±19 MeV that is 388±44±32 MeV wide • Spin parity studied JP = 1- is favored • The resonance is most likely r(1450) (r) • Theory predictions compared Jianchun (JC) Wang

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