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Resonances in decay (for 400fb -1 ) BAM February 27th, 2006

Detailed analysis of B+ decay into D0D0K+ interaction, with focus on resonance characteristics and angular distributions. The study confirms presence of DsJ(2700) resonance and explores related parameters.

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Resonances in decay (for 400fb -1 ) BAM February 27th, 2006

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  1. B+ D0D0K+ Resonances in decay (for 400fb-1) BAM February 27th, 2006 J.Brodzicka, H.Palka INP Kraków • Outline : • B+ D0D0K+for 400fb-1 • Dalitz plot and projections • Background-free 2-body mass distributions • Fits to massdistributions, the DsJ(2700) and charmonia parameters • Angular distrbutions • Conclusions

  2. B+ D0D0K+ BF = (1.31 ± 0.13 + 0.17 ) 10-3 BF = (1.25 ± 0.16 + 0.16 ) 10-3 – 0.27 – 0.27 for E<20MeV~3 for Mbc>5.273GeV~3 LR>0.01 Fitting method: 2-dimensional unbinned likelihoodfit on theMbc vs.E plane Signal Bckgd. 400 fb-1:399±40 ~1500 ( 250 fb-1: 234 ± 30 ~ 900 J.Brodzicka, H.Palka INP BAM February 27th, 2006

  3. (3770) (3770) (4160) (4160) DsJ(2700) DsJ(2700) DsJ(2700) (4160) (3770) B+ D0D0K+ Dalitz-plot projections for LR > 0.01 For Mbc > 5.277GeV E<10 MeV( ~1.5Mbc, E signal region ) Background:elliptical strip 6 to 10 in Mbc, E, surrounding the signal region for 400fb-1 for 250fb-1 J.Brodzicka, H.Palka INP BAM February 27th, 2006

  4. DsJ(2700) +(4160) reflection (4160) +DsJ(2700) reflection (3770) fitted B Signal Background-freeinvariant mass distributions 2-dim Mbc-E fits in 2-body inv. mass bins B signal in mass bins Background-free mass spectra are very consistent with the Dalitz-plot projections over the estimated background. J.Brodzicka, H.Palka INP BAM February 27th, 2006

  5. for for M(D0D0)>3.85 GeV (4160) in½helicity distr: 24 ± 11events (~2σ) (to remove (3770)reflection from high M(D0K+) region) (for 2nd half helicity distr: 20% smaller efficiency) Lower curve: MC predicted (4160)reflection + non-resonant component described by 3-body MC Estimation of the resonance contributions DsJ(2700) (3770) (4160) Z(3930) Breit Wigner functions + threshold function DsJ(2700) parameters consistent with previous estimations Non-resonant component yield: 47 ± 32 J.Brodzicka, H.Palka INP BAM February 27th, 2006

  6. B+ (4160)K+ B+ (3770)K+ B+ D0DsJ+(2700) DsJ+(2700), (3770) are not the full story, but the ‘fit’ is acceptable Explanation of2-body mass spectra Contributions from quasi-two-body components: (normalized to measured yields and superimposed by adding histograms) Shapes predicted by MC simulations J.Brodzicka, H.Palka INP BAM February 27th, 2006

  7. B+ (4160)K+ B+ (3770)K+ B+ D0DsJ+(2700) Background-free mass distr. corrected for acceptance (3770) DsJ(2700) Z(3930) • M(D0D0) strongly affected by acceptance losses • influence of these losses on DsJ(2700) regionis minor J.Brodzicka, H.Palka INP BAM February 27th, 2006

  8. fitted B Signal corrected for acceptance (4160) reflection Angular distributions in the helicity frames of DsJ(2700) and (3770) Background-free cos distributions obtained using 2-dim Mbc-E fit in eachcos bin DsJ(2700) region:2.5<M(D0K+)<2.9 GeV DsJ(2700)spin hypotheses: J=1 2/n.d.f = 3.4/4 J=2 2/n.d.f = 16.2/4 J=0 2/n.d.f = 36.5/4 1-favoured (3770) region:M(D0D0)< 3.85 GeV (3770) spin hypothesis: J=12/n.d.f = 3.5/5 J.Brodzicka, H.Palka INP BAM February 27th, 2006

  9. Summary • 400 fb-1 sample has been analysed; all features seen in the 250 fb-1 sample are confirmed • strong DsJ(2700)→D0K+resonance(significance = 6.7σ) M= 2709 ± 10 MeV Γ= 137 ± 27 MeV JP=1- favoured • Ψ(3770) confirmed M= 3777 ± 3 MeV Γ= 27 ± 9 MeV • remaining structures in M(D0D0) could not be resolved, but their influence on the DsJ(2700) parameters is small (included into systematic errors) • We would like to publish DsJ(2700) as it is now, deeper insight into M(D0D0) and M(D0K+) dynamics will be possible after full Dalitz plot analysis (if it is successful) J.Brodzicka, H.Palka INP BAM February 27th, 2006

  10. Backups J.Brodzicka, H.Palka INP BAM February 27th, 2006

  11. DsJ(2700) (3770) (4160) DsJ(2700) (4160) (3770) DsJ(2700) (4160) (4160) (3770) DsJ(2700) (3770) Dalitz plot and projections for B+ D0D0K+ LR > 0.01 For Mbc > 5.277GeV E<10 MeV( 1.5 signal region ) Background:elliptical strip 6 to 10 in Mbc, E, surrounding the signal region J.Brodzicka, H.Palka INP BAM February 27th, 2006

  12. Dalitz plot projections for with smaller 20MeV binning B+ D0D0K+ LR > 0.01 For 1.5E-Mbc signal region Background for 400fb-1  no significant narow states J.Brodzicka, H.Palka INP BAM February 27th, 2006

  13. Efficiency map forB+ D0D0K+ D0 KπD0 Kπ, K3π,Kππ0,Ksππ, KK [10-3] Acceptance losses over the Dalitz plot Acceptance corrections for mass distributions Wacc = Nrec(M)/Ngen(M) J.Brodzicka, H.Palka INP BAM February 27th, 2006

  14. Events from 1.5E-Mbc signal region Background Mass distributions corrected for acceptance J.Brodzicka, H.Palka INP BAM February 27th, 2006

  15. Comparison with the DsJ(2700)spin hypotheses: J=1 2/n.d.f = 3.4/4 J=2 2/n.d.f = 16.2/4 J=0 2/n.d.f = 36.5/4 fitted B Signal corrected for acceptance Angular distribution in the helicity frame of DsJ(2700) J.Brodzicka, H.Palka INP BAM February 27th, 2006

  16. DsJ(2700) Explanation of2-body mass spectra with no ψ(4160) contribution NDsJ = 231 ± 32 MDsJ = 2706 ± 9 MeV ΓDsJ = 136 ± 25 MeV

  17. J.Brodzicka, H.Palka INP BAM February 27th, 2006

  18. J.Brodzicka, H.Palka INP BAM February 27th, 2006

  19. Systematic error contributions to BF (B+ D0D0K+) J.Brodzicka, H.Palka INP BAM February 27th, 2006

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