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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 for 190fb -1 B + D 0 D 0 K + B 0 D - D 0 K + signals for 190fb -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 for 190fb -1 (exp7-35)

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 190fb -1 for 190fb -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 M 2 ( D 0 K + ) D sJ (2720) (4160) (4160) (3770) (3770) D sJ (2573) 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( 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) ? (3770) reflection (3770) reflection (4160) reflection possible (4160) reflection possible N / 20MeV ?

10 D sJ (2720) D sJ (2573) 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 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 + D sJ (2573) peak at GeV seen, no D sJ (2573) D sJ (2573) D sJ (2720) and D sJ (2720) observed observed M(D 0 D 0 ) (4160) (4160) Signal / 50MeV M(D 0 D 0 )>3845 (4160) (4160) contribution tiny (if any) (3770) (3770) region removed (4160) contributing to 2720 peak is the (4160) contributing to 2720 peak? M(D 0 D 0 ) for high D 0 K + masses (4160) ( ½ of the (4160) helicity distr.)

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, (-> fit unreasonable numerically, see previous attempts) the convolution BW G( =50MeV) is used D sJ (2573) peak narrower than the bin width, (-> fit unreasonable numerically, see previous attempts) the convolution BW G( =50MeV) is used Phase Space (nonresonant component) is described by linear function Phase Space (nonresonant component) is described by linear function 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 B 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 cos cos Acceptance for signal MC D - D 0 K+ : D - D 0 K+ (K )(K ) :

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 B Signal with error corrected for acceptance Signal Signal cos cos Acceptance for signal MC D - D 0 K+ : D - D 0 K+ (K )(K ) : Acceptance for signal MC D 0 D 0 K+ : D 0 D 0 K+ (K )(K ) : Very asymmetric -interference effect ? -interference with what? (no significant structures (no significant structures are seen in other Dalitz are seen in other Dalitz plot projections ) plot projections )

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 do meaningfull fit M( D 0 K + ) needed to do meaningfull fit M( D 0 K + ) (e.g. wrong flavor D 0 K - combination) analysis for continuum MC will analysis for continuum MC will be done be done > 150 events (by counting)

16 Jolanta Brodzicka, Henryk Palka INP Krakow BAM July 15, 2004 Conclusions The new resonant structure in D 0 K + is observed in B decays: The new resonant 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 any other stuctures in the Dalitz plot It is not reflection from any other stuctures in the Dalitz plot Its helicity distribution is puzzling in (rather asymmetric) Its helicity distribution is puzzling in (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 ) B 0 D - D 0 K + B 0 D - D 0 K + (rather surprising) Draft of the conf. paper and the B_Note are on the way Draft of the conf. paper and the B_Note are on the way Exp. 37 data set will be added Exp. 37 data set will be added D 0 K + from other doubly charmed B decays are studied: D 0 K + from other doubly charmed B decays are studied: B 0 D *- D 0 K + B 0 D *- D 0 K + B + D *0 D 0 K + B + D *0 D 0 K + but inconclusive at 140fb-1 D*K from spectrum is also studied in doubly charmed B decays D*K from spectrum is also studied in doubly charmed B decays and produced from continuum and produced from continuum

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

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 D*K from continuum M(D * K ) N/20MeV D 0 K D*K vertex fit with IP constraint (to reduce background) cl>.1 P*(DK) > 3.5 GeV in (4S) system for 140 fb -1 D* + K 0 s, D* 0 K + M(D)-M(D PDG ) < 20MeV D s1 (2536) It seems to be quite rich

21 Jolanta Brodzicka, Henryk Palka INP Krakow BAM July 15, 2004 Fit variants Signal / 50MeV M( D 0 K + ) Signal / 50MeV Nonresonant componentNonresonant component is described by 3-body MC distribution distribution Mass fixed to 2720MeV Mass fixed to 2720MeV 2 similar 2 similar

22 Jolanta Brodzicka, Henryk Palka INP Krakow BAM July 15, 2004 Background subtracted mass distributions Background subtracted mass distributions B + D 0 D 0 K + M( D 0 D 0 ) M( D 0 K + ) wrong flavour comb. Signal / 50MeV Signal / 25MeV

23 J OLANTA B RODZICKA BGM Nov 21, 2003 B D (*) D (*) K Supporting evidence in D*K Supporting evidence in D*K ? B + D 0 D* 0 K + B 0 D* - D* 0 K + B D (*) D* 0 K + S / 50MeV M( D* 0 K + ) Partially reconstructed: B D 0 D* 0 K + + lost S / 25MeV N = 50.7 ± 15.3 M = ± GeV = ± GeV M( D* 0 K + ) Fitted:G+BW+BW+&PS N = 3.8 ± 1.6 M = GeV fixed = GeV fixed (exp.resol) D S1 (2536) ? N = 27.7 ± 8.0 M = ± GeV = ± GeV B + D 0 D* + K 0 s Partially reconstructed: B + D 0 D* + K 0 s + lost B D (*) D* + K 0 s M(D* + K 0 s ) S / 50MeV SIGNAL with subtracted bckg PS for 3body MC

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


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