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New Resonance in D 0 K + Andrzej Bozek for Jolanta Brodzicka & Henryk Palka INP Krakow INP KrakowBAM July 15, 2004 Outline : Physics motivations Physics.

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Presentation on theme: "New Resonance in D 0 K + Andrzej Bozek for Jolanta Brodzicka & Henryk Palka INP Krakow INP KrakowBAM July 15, 2004 Outline : Physics motivations Physics."— Presentation transcript:

1 New Resonance in D 0 K + Andrzej Bozek for Jolanta Brodzicka & Henryk Palka INP Krakow INP KrakowBAM July 15, 2004 Outline : Physics motivations Physics motivations Analysis method Analysis method B + D 0 D 0 K + B 0 D - D 0 K + signals in 200fb -1 B + D 0 D 0 K + B 0 D - D 0 K + signals in 200fb -1 Dalitz plots and projections Dalitz plots and projections Background subtracted M(D 0 K + ) distributions Background subtracted M(D 0 K + ) distributions D sJ (2573) & D sJ (2720) D sJ (2573) & D sJ (2720) Angular distrbutions Angular distrbutions Supporting evidence from continuum Supporting evidence from continuum Conlusions Conlusions

2 Jolanta Brodzicka, Henryk Palka INP Krakow BAM July 15, 2004 Physics motivations Inconsistent with model predictions Do not decay to DK, D*K Is it a good assignement? Chiral doublet for Ds 0 - and Ds* 1 - ? Well known Scarcely known not seen in B decays Chiral partners expected L = 1 Parity+ j q = 3 / 2 J = 2 j q = 3 / 2 J = 2 J = 1 J = 1 j q = ½ J = 1 j q = ½ J = 1 J = 0 J = 0 L = 0 Parity - L = 0 Parity - j q = ½ J = 1 j q = ½ J = 1 J = 0 J = 0 Ds* (2112) Ds (1968) Ds (1968) D SJ (2573) D S1 (2536) D SJ (2457) D SJ (2317) L = 2 …? L = 2 …? n = 2 … n = 1 J : total spin of meson L : orbital momentum of light quark j q : light quark angular mom. cs multiplets : uncomplete/umbiguous ( ? ) cs multiplets : uncomplete/umbiguous ( ? ) assignment assignment recent intriguing discoveries: recent intriguing discoveries: D SJ (2317), D SJ (2457), SELEX state (?) D SJ (2317), D SJ (2457), SELEX state (?)

3 Jolanta Brodzicka, Henryk Palka INP Krakow BAM July 15, 2004 B D ( * ) D ( * ) K : good place to explore spectroscopy: b cW - c c s + dd (uu) D ( * ) K from W vertex B 0 D - D 0 K + Physics motivations (2) Leading quark diagrams: only External diagram only External diagram D 0 K + is the only non-exotic comb., D 0 K + is the only non-exotic comb., D - D 0 have > 2q content D - D 0 have > 2q content B + D 0 D 0 K + External + Internal diagrams External + Internal diagrams Both DK and DD states expected Both DK and DD states expected D 0 K + is exotic D 0 K + is exotic _

4 Jolanta Brodzicka, Henryk Palka INP Krakow BAM July 15, 2004 selection cuts accepted events : R 2 < 0.3 tracks : IP _ dz < 5cm IP _ dr < 0.4cm K ± : P( K/ ) > 0.4 ± : P( /K ) > 0.1 electron veto: el_id < 0.95 K 0 S : M( + - ) - M Ks <15MeV only good K 0 s accepted 0 : E >50 MeV M ( ) - M 0 < 15MeV D reconstruction D 0 K, K3, K 0, K s, KK BF ~ 28% of total D ± K, K s, KK, K s K BF ~ 12% of total M(D)-M(D PDG ) < 20MeV ( D 0 K 0 : -50MeV ) vertex fit (cl > 0.) and mass constraint fit applied p(D) < 2 GeV in (4S) system B DDK reconstruction B vertex fit: with IP and B constraints M bc > 5.2 GeV < E < 0.35 GeV Analysis method

5 Jolanta Brodzicka, Henryk Palka INP Krakow BAM July 15, 2004 Multi-candidates events treatment D probabilities ( LR_D ): LR_D ( M D ) LR_D ( M D )= B(M D ) S(M D ) + S(M D ), B(M D ) parameterization from fits to data ( inclusively reconstructed D 0, D ± in each decay mode separately ) D plots for ~11fb -1 after preselection p(D) < 2GeV in (4S) system B probability ( LR_B ): LR_B = LR_D 1 × LR_D 2 LR_B used also for background discrimination background discrimination equal LR_B case: larger K ± _ID candidate chosen max LR_B best B candidate : with max LR_B MDMDMDMD D 0 K D 0 K MDMDMDMD D 0 K3 D 0 K3 MDMDMDMD D ± K s D ± K s MDMDMDMD D ± K D ± K MDMDMDMD D 0 K 0 LR_D LR_D

6 Jolanta Brodzicka, Henryk Palka INP Krakow BAM July 15, 2004 E N/7.5MeV plot for M bc >5.27 GeV N/2.5MeV M bc plot for E <25MeV Fitting method: 2-dim M bc vs. E unbinned likelihood fit: L_Sig( M bc, E) = S ( G ( M bc ) G ( E) ) + S ( G ( M bc ) G ( E) ) + S ( G ( M bc ) G ( E) ) + S 2 ( G ( M bc ) G ( E) ) 2 + S 2 ( G ( M bc ) G ( E) ) 2 L_Bckg ( M bc, E) = B ARG ( M bc ) POL_2 ( E ) L= L_Sig + L_Bckg L= L_Sig + L_Bckg LR > 0.04 B + D 0 D 0 K + S = ± 14.8 G 0 ( E) = -0.32E-02 ± 0.08E-02 ( E) = 0.52E-02 ± 0.07E-02 ( E) = 0.52E-02 ± 0.07E-02 G 0 (Mbc) = ± (Mbc) = 0.24E-02 ± 0.03E-02 (Mbc) = 0.24E-02 ± 0.03E-02 S, S 2 : regions with missing,2 S, S 2 : regions with missing,2 Fit result:

7 Jolanta Brodzicka, Henryk Palka INP Krakow BAM July 15, 2004 B 0 D - D 0 K + LR > 0.01 S = ± 16.6 G 0 ( E) = -0.19E-02 ± 0.08E-02 ( E) = 0.57E-02 ± 0.06E-02 ( E) = 0.57E-02 ± 0.06E-02 G 0 (Mbc) = ± (Mbc) = 0.26E-02 ± 0.03E-02 (Mbc) = 0.26E-02 ± 0.03E-02 E N/7.5MeV plot for M bc >5.27 GeV N/2.5MeV M bc plot for E <25MeV Fit result ( for fully reconstructed region):

8 Jolanta Brodzicka, Henryk Palka INP Krakow BAM July 15, 2004 ModeSignal for 140fb -1 for 140fb -1 eff [ ] eff [ ] BF [ ] Signal for 200fb -1 for 200fb -1 B + D 0 D 0 K ± ± ± 0.18 ± ± 14.8 B 0 D - D 0 K ± ± ± 0.20 ± ± 16.6 BF calculations based on 140fb -1

9 Jolanta Brodzicka, Henryk Palka INP Krakow BAM July 15, 2004 Dalitz plot and projections for Background: ellipsoidal strip 6 to 10 Background: ellipsoidal strip 6 to 10 in Mbc, E, surrounding the signal region in Mbc, E, surrounding the signal region B + D 0 D 0 K + M 2 ( D 0 K + ) M( D 0 K + ) N / 20MeV M( D 0 D 0 ) M( D 0 K + ) M 2 ( D 0 D 0 ) for signal-box events : for signal-box events : Mbc > GeV E GeV E <16 MeV (~3 ) LR > 0.04 (3770) (3770) (4160) (4160) (4040) (4040) D sJ (2573) D sJ (2720) ? reflection from (3770) (3770) (4160) reflection possible (4160) reflection possible N / 20MeV

10 Jolanta Brodzicka, Henryk Palka INP Krakow BAM July 15, 2004 Dalitz plot and projections B 0 D - D 0 K + M 2 ( D 0 D - ) M 2 ( D 0 K + ) M( D 0 K + )M( D - K + ) M( D - D 0 ) N / 20MeV for signal-box events : for signal-box events : Mbc > GeV E <18 MeV (~3 ) N / 20MeV LR > 0.01 D sJ (2720) ? D sJ (2573) Background

11 Jolanta Brodzicka, Henryk Palka INP Krakow BAM July 15, 2004 M(D 0 K + ) background subtracted distributions 2dim M bc vs. E fits in M( D 0 K + ) bins (to filter out background from Dalitz-plot projection) B signal in M( D 0 K + ) bins fitted Signal with error M( D 0 K + ) Signal / 50MeV B 0 D - D 0 K + B + D 0 D 0 K + (3770) (3770) region removed (M(D 0 D 0 )>3845 (3 ) ) D sJ (2573) no contribution from D sJ (2573) peak at GeV (4160) Is the significant reflection from (4160) ? D sJ (2573) D sJ (2720) D sJ (2573) and D sJ (2720) observed observed M(D 0 D 0 ) (4160) Estimation of (4160) in 2720 region: ) M(DD) for Dalitz plot region with high D 0 K + masses negligible contribution (4160) (4160) Signal / 50MeV

12 Jolanta Brodzicka, Henryk Palka INP Krakow BAM July 15, 2004 resonances described by non-relativistic Breit-Wigners resonances described by non-relativistic Breit-Wigners D sJ (2573) peak narrower than the bin width, D sJ (2573) peak narrower than the bin width, the convolution BW G( =50MeV) is used the convolution BW G( =50MeV) is used Phase Space (nonresonant component) is described by 2 nd order polynomial Phase Space (nonresonant component) is described by 2 nd order polynomial Fits to background subtracted mass spectra Fits to background subtracted D 0 K + mass spectra Signal / 50MeV fitted B Signal M( D 0 K + ) N = 39.5 ± 7.6 M = 2742 ± 6 MeV = 80 ± 27 MeV = 80 ± 27 MeV N = 80.3 ± 14.0 M = 2718 ± 8 MeV = 79 ± 18 MeV = 79 ± 18 MeV N = 13.3 ± 4.2 M = 2569 ± 8 MeV = 15 MeV fixed = 15 MeV fixed D sJ (2720) D sJ (2573) B + D 0 D 0 K + B 0 D - D 0 K +

13 Jolanta Brodzicka, Henryk Palka INP Krakow BAM July 15, 2004 Angular distribution Helicity angle : angle between K + momentum in D 0 K + rest frame and D 0 K + momentum (boost direction) D D0K+D0K+ D0D0 K+K+ B cos distribution obtained using 2-dim M bc vs. E fit in each cos bin (to subtract background) fitted Signal with error corrected for acceptance D SJ (2573) region: B 0 D - D 0 K + signal-box and 2.54 < M(D 0 K + ) < 2.6 GeV ( 30 MeV window ) ( 30 MeV window ) Signal cos cos Compatible with J=2Compatible with J=2

14 Jolanta Brodzicka, Henryk Pałka INP Kraków BAM July 15, 2004 Angular distribution (2) D sJ (2720) region: B DD 0 K + signal-box and 2.64 < M(D 0 K + ) < 2.8 GeV ( 80MeV window ) B 0 D - D 0 K + B + D 0 D 0 K + cos cos fitted Signal with error corrected for acceptance Signal Signal cos cos Very asymmetric

15 Jolanta Brodzicka, Henryk Palka INP Krakow BAM July 15, 2004 D sJ (2573) D sJ (2720) M( D 0 K + ) N/20MeV D 0 K + from continuum D 0 K DK vertex fit with IP constraint (to reduce background) cl>.9 P*(DK) > 3.5 GeV in (4S) system M(D)-M(D PDG ) < 20MeV for 140 fb -1 background parameterization needed to perform M( D 0 K + ) fit needed to perform M( D 0 K + ) fit (candidate: M distribution for wrong flavor D 0 K - combination) smaller D sJ (2720) width can be due to background fluctuations background fluctuations 150 events by counting

16 Jolanta Brodzicka, Henryk Palka INP Krakow BAM July 15, 2004 Conclusions The new structure in D 0 K + is observed in B decays: The new structure in D 0 K + is observed in B decays: B + D 0 D 0 K + ( 5.2 σ ) and B 0 D - D 0 K + ( 5.7 σ) M = 2742 ± 6 MeV = 80 ± 27 MeV = 80 ± 27 MeV M = 2718 ± 8 MeV = 79 ± 18 MeV = 79 ± 18 MeV It is not reflection from some other stuctures in the Dalitz plot It is not reflection from some other stuctures in the Dalitz plot Its helicity distribution is puzzling (rather asymmetric) Its helicity distribution is puzzling (rather asymmetric) Supporting evidence from continuum produced D 0 K + spectrum Supporting evidence from continuum produced D 0 K + spectrum Evidence for D sJ (2573) D 0 K + in B 0 D - D 0 K + ( 3.2 σ ) Evidence for D sJ (2573) D 0 K + in B 0 D - D 0 K + ( 3.2 σ )

17 Jolanta Brodzicka, Henryk Pałka INP Kraków BAM July 15, 2004 Conclusions The structure in D 0 K + is observed in B decays: The structure in D 0 K + is observed in B decays: B + D 0 D 0 K + ( 4 σ ) and B 0 D - D 0 K + ( 7 σ) B + D 0 D 0 K + ( 4 σ ) and B 0 D - D 0 K + ( 7 σ) m=2720±10 MeV, m=2720±10 MeV, m=2720±10 MeV, m=2720±10 MeV, Γ=80±30 Γ=80±30 Γ=80±30 Γ=80±30 =, = =, = It does not seem to be due to reflections from some other stuctures in the It does not seem to be due to reflections from some other stuctures in the Dalitz plot (however quantitative Dalitz plot analysis is not possible yet) Dalitz plot (however quantitative Dalitz plot analysis is not possible yet) Its helicity distribution is puzzling (rather asymmetric) Its helicity distribution is puzzling (rather asymmetric) Continuum produced D 0 K + spectrum is unconclusive ( <3 σ effect) Continuum produced D 0 K + spectrum is unconclusive ( <3 σ effect) Evidence for D sJ (2573) D 0 K + in B 0 D - D 0 K + ( 3 σ) Evidence for D sJ (2573) D 0 K + in B 0 D - D 0 K + ( 3 σ) High mass charmonia are also seen in B + D 0 D 0 K + High mass charmonia are also seen in B + D 0 D 0 K + Ψ(4160) D 0 D 0 is observed ( 4 σ) m =4150±20 MeV, Γ=120±30 Ψ(4160) D 0 D 0 is observed ( 4 σ) m =4150±20 MeV, Γ=120±30 Ψ(4160) D 0 D 0 is confirmed ( ) m =4150±20 MeV, Γ=120±30 Ψ(4160) D 0 D 0 is confirmed ( ) m =4150±20 MeV, Γ=120±30 we have no hint for Ψ(4040) we have no hint for Ψ(4040) Exp.37 data set will be added Exp.37 data set will be added Draft of the conference paper is almost ready, Belle_Note is half-ready Draft of the conference paper is almost ready, Belle_Note is half-ready

18 Jolanta Brodzicka, Henryk Palka INP Krakow BAM July 15, 2004 M bc & E movie from 2dim M bc vs. E fit in M( D 0 K + ) 50MeV bins for B 0 D - D 0 K + from 2dim M bc vs. E fit in M( D 0 K + ) 50MeV bins for B 0 D - D 0 K + E M bc E M( D 0 K + ) bin

19 Jolanta Brodzicka, Henryk Palka INP Krakow BAM July 15, 2004 M bc & E movie ( 2 ) M( D 0 K + ) bin E M bc E – 3.0 B 0 D - D 0 K +

20 Jolanta Brodzicka, Henryk Palka INP Krakow BAM July 15, 2004 Backup slides


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