The New Narrow D s States A minireview

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1 The New Narrow D s States A minireview Frank Porter Caltech (From the BaBar Collaboration) Results from: BaBar (abstract 395, PRL 9 (23) 2421, A. Palano PIC) Belle (abstract 57, R. Chistov & K. Trabelsi FPCP 23) CLEO (abstract 813, hep-ex/351, submitted to PRD, J. Urheim CIPANP) CDF (M. Shapiro FPCP 23) Two new narrow states (names from presumed quantum numbers, q q model): D sj (2317)± D sj (246) ± 1 Frank Porter, 17 July 23, International Europhysics Conference on High Energy Physics

2 The D s Level Scheme Light quark angular momentum (j), combined with heavy quark spin. l = 2... l = states l =... P -wave multiplet j = 3/2 2 4 states mixing j = 1/2 2 2 Spin-Orbit Tensor Force P J = 2 5 states P J = 1 3 P J = 1 3 P J = 1 ) 2 Mass (GeV/c Godfrey/Isgur (1985) Di Pierro/Eichten (21) Observed Newly Discovered * D K DK P J = Figures: Courtesy of David Williams Conventional wisdom: P -wave j =1/2 states heavy enough for isospinallowed strong decays to produce large widths. E.g., Ds ± D K ±. 2 Frank Porter, 17 July 23, International Europhysics Conference on High Energy Physics

3 The New Narrow State at 2317 MeV in M(D s π ) Mass peak consistent with experimental resolution. Hence Γ < several MeV. BaBar D s φπ D s K Kπ E vents/5mev Belle preliminary π sideband Ds sideband D s KKππ M(Ds π ) - M(Ds) G ev/c 2 8 Events/5MeV/c 2 4 CLEO Data qq Monte Carlo (a) M(D s π ) (GeV/c 2 ) 3 Frank Porter, 17 July 23, International Europhysics Conference on High Energy Physics

4 Isospin of State at M = 2317 MeV Narrow decay width suggests isospin violating decay, I 1. Not seen in D ± s π, D ± s π ±, hence I =. CDF preliminary 2 Number of Candidates/ 2 MeV/c CDF Run II Preliminary Signal Window: 246 D 2 RMS: 7.6 MeV/c s s -1 ~8 pb Number of Entries / 1 MeV CDF Run II Preliminary p t (π) > 35 MeV/c -1 ~8 pb Dsπ - Ds π Mass of φπ Candidates [GeV/c ] M(D s π ) candidate (GeV) Sensitivity estimated with D 2 Dπ modes, relative D s:d rates. WorkingtofurtherquantifyusingD sj (2573) DK for normalization. 4 Frank Porter, 17 July 23, International Europhysics Conference on High Energy Physics

5 D sj (2317)± Spin-Parity D sj (2317) D sπ. If parity conserved, then natural J P (hence ). BaBar DsJ (2317) D sπ helicity angle distribution consistent with uniform; consistent with,orwith isotropic polarization. Events/2MeV/c Not seen in D s π π or D s π π, which are forbidden for : 2317 CLEO M(D π π - s )-M(Ds ) (GeV) BaBar M(D π π ) (GeV) s Number of E ntries / 1 MeV CDF preliminary C DF R un II P reliminary 16 Minimum P ion p t > 35 MeV/c 2317 Dsπ π - Ds π- π - -1 ~8 pb Dsπ π M(D s ππ) (GeV) 5 Frank Porter, 17 July 23, International Europhysics Conference on High Energy Physics

6 D sj (2317)± Spin-Parity (continued) Belle preliminary B DD s γ If DsJ (2317) is spin zero, then decay to D s γ is forbidden. Not seen (c) M(D s γ ) (GeV) CLEO 1 3 Events/5MeV/c (a) BaBar M(D s γ)-m(d s ) (GeV/c 2 ) Look forward to angular analysis in B DDsJ (2317) decays. 6 Frank Porter, 17 July 23, International Europhysics Conference on High Energy Physics

7 Observation of D sj (2317) in Exclusive B DD sπ Decays Events/1 MeV 1 (Belle preliminary, B B, D s φπ, K K,K S K ) 2 (a) E (GeV) Events/1 MeV 2 (a) M(D π ) (GeV) s B Decay channel Yield ( E) B(1 4 ) D DsJ (2317), D sj (2317) D sπ D DsJ (2317), D sj (2317) D sπ D DsJ (2317), D sj (2317) D sγ (< 5.7) D D sj (2317), D sj (2317) D sγ (< 7.1) cf (RPP 22): B D D s =(1.3 ±.4)%, B D D s =(.8 ±.3)%; B D D s =(.9 ±.4)%, B D D s =(1. ±.5)%. 7 Frank Porter, 17 July 23, International Europhysics Conference on High Energy Physics

8 D sj (2317)± Summary Quantity BaBar Belle CLEO Dataset (fb 1 ) D s Modes φπ, K K φπ φπ Mass (MeV) ±.4 ± ±.5 ± ± 1.2 ± 1.1 M(2317) M(D s ) (MeV) ±.4 ± ±.5 ± ± 1.2 ± 1. Width (MeV, 9% C.L.) < 1 < 7 B(D s π π )/B(D s π ) (9% C.L.) <.19 B(D s γ)/b(d s π ) (9% C.L.) <.5 <.52 B(D s π )/B(D s π ) (9% C.L.) <.11 B(D sγ)/b(d s π ) (9% C.L.) <.59 σ B(D sj D sπ ) σ(d s ) (p >3.5 GeV) (7.9 ± 1.2 ±.4) 1 2 σ =7.6 ±.5 MeV consistent with resolution. I = favored (Narrow width to D s π, CDF search in D s π ± ) J P natural, consistent with 8 Frank Porter, 17 July 23, International Europhysics Conference on High Energy Physics

9 The New Narrow State at 246 MeV in D s π γ Mass peak consistent with experimental resolution. Hence Γ < several MeV. Events / 5 MeV/c CLEO D* s region D s * sideband region (a) (b) E vents/5mev Belle preliminary π sideband Ds * region M(D s γπ ) - M(D s γ) (GeV/c 2 ) D* s region M(Ds* π ) - M(Ds*) G ev/c 2 BaBar preliminary Ds * sideband 9 Frank Porter, 17 July 23, International Europhysics Conference on High Energy Physics

10 Reflection (Cross-feed) Ambiguity M(D sj (246) D s(2112)) M(D sj (2317) D s) 35 MeV Feed-up of D sj (2317) to D sj(246) peak possible by adding a random photon consistent with D s(2112) D s γ. Feed-down of D sj (246) to DsJ (2317) peak possible by neglecting the photon in the D s(2112) D s γ transition. Ambiguity in D sj (246) decays: Is it D sj (246) D s(2112)π or D sj (246) D sj (2317)γ? BaBar/Belle/CLEO all correct for cross-feeds under the D sj (246) D s (2112)π hypothesis. 1 Frank Porter, 17 July 23, International Europhysics Conference on High Energy Physics

11 Study of Cross-feed Ambiguity (BaBar preliminary) 246 boundary D s π γ:them(d s γ)vsm(d s π ) scatter plot. Data Monte Carlo Projections with linear background subtraction: Is it D sj (246) Ds(2112)π? Is it D sj (246) DsJ (2317)γ? Conclusion: Much better fit to D sj (246) D s (2112)π 11 Frank Porter, 17 July 23, International Europhysics Conference on High Energy Physics

12 D sj (246) Spin-Parity Observed in D sj (246) D s γ, hence J. Events/5MeV M(Ds γ) - M(Ds) GeV/c 2 Belle preliminary; Continuum No D sj (2317) seen (forbidden for spin ) N(D sj (246) D s γ) = 152 ± 18 ± 11 Rules out J = Helicity angle in D sj (246) D s(2112)π, D s(2112)π D s γ (BaBar preliminary) Inconsistent with J P =. [nb: no prediction for 1, 2.] θ γ D s * D s (2112). D (246) sj π 12 Frank Porter, 17 July 23, International Europhysics Conference on High Energy Physics

13 Angular analysis in B DD sj (246) DD s γ (Belle preliminary) (c) 2 B DD s γ M(D s γ ) (GeV) B(B DD sj (246) DD s γ) = ( ± 2.) 1 4 B(D sj (246) D s γ) B(D sj (246) D sπ ) =.38 ±.11 ±.4 Events B DD sj (246) DD s γ Data = points with errors Spin 1 = histogram; Spin 2 = dashed line. Consistent with sin 2 θ, as expected for cos(θ Dsγ ) 13 Frank Porter, 17 July 23, International Europhysics Conference on High Energy Physics

14 Observation in Exclusive B Decays (Belle preliminary) B B B DD ( ) sj, D Kπ, Kππ, Kπππ, D s φπ, K K,K S K 2 (a) 1 2 (a) M(D 1 s π ) Events/(.1 GeV) 1 2 (b) (c) Events/(.1 GeV) 2 (b) M(D* π 1 2 s M(D ) γ s ) (c) E (GeV) M(D sj ) (GeV/c 2 ) 14 Frank Porter, 17 July 23, International Europhysics Conference on High Energy Physics

15 Exclusive B Decays (Belle preliminary) B Decay channel Yield ( E) B(1 4 ) D D sj (246), D sj (246) D sπ ± 3.6 D D sj (246), D sj (246) Ds π ± 6.8 D D sj (246), D sj (246) D s γ ± 1.7 D D sj (246), D sj (246) D s γ D D sj (246), D sj (246) Dsγ (< 7.5) D D sj (246), D sj (246) D s γ D D sj (246), D sj (246) D s π < 2.4 < 2.2 D D sj (246), D sj (246) D s π < 2.4 < 2.8 D D sj (246), D sj (246) D s π π < 4. < 2.4 D D sj (246), D sj (246) D s π π < 2.5 < 2. (< 4.6) 15 Frank Porter, 17 July 23, International Europhysics Conference on High Energy Physics

16 D sj (246) Summary Quantity BaBar Belle CLEO Dataset (fb 1 ) N(D s π,d s D sγ) 127 ± ± 25 ± ± 12 Mass (MeV) ± 1.4 ± ± 1.3 ± ± 1.7 ± 1.2 M(246) M(Ds )(MeV) ± 1.2 ± ± 1.3 ± ± 1.7 ± 1. Width (MeV, 9% C.L.) < 7 B(D s π π ) B(Dsπ ) (9% C.L.) <.8 B(D s γ) B(Dsπ ) (9% C.L.).63 ±.15 ±.15 <.49 B(Ds γ) B(Dsπ ) (9% C.L.) <.16 B(D sj (2317) γ) B(Dsπ ) (9% C.L.) <.58 Width of mass peak is consistent with resolution. J P ±, consistent with 1. Not seen in D s π ±, D s π π modes in CDF. Not seen in D s π π in B decays in Belle. 16 Frank Porter, 17 July 23, International Europhysics Conference on High Energy Physics

17 Production Rates (p CM > 3.5 GeV) CLEO σ B(D sj D s γ) σ(d s ) =.59 ±.3 ±.1 σ B(D sj (2317) D s π ) σ(d s ) =(7.9 ± 1.2 ±.4) 1 2 σ B(D sj (246) D s π ) σ(d s ) =(3.5 ±.9 ±.2) 1 2 Belle Preliminary σ B(D sj (246) D s π ) σ B(D sj (2317) D s π ) =.26 ±.5 ±.6 σ B(D sj (246) D s π ) σ B(D sj (2317) D s π ) <.6 (9% C.L.) 17 Frank Porter, 17 July 23, International Europhysics Conference on High Energy Physics

18 Summary Two new narrow states have been observed with c s content: DsJ (2317) and D sj(246). They are consistent with being and 1 states, respectively. Their masses are lower than consensus expectation in c s spectroscopy. Mass of D sj (246) on margin of inconsistency among experiments: BaBar ± 1.4 ± 3 Belle ± 1.3 ± 1.1 CLEO ± 1.7 ± 1.2 Weighted Average ± 1.2 Adding systematic and statistical uncertainties in quadrature; neglecting possible correlations (eg, from Ds mass uncertainty of.7 MeV). χ 2 probability for consistency is 3%. For mass difference, weighted average is ± 1.2, with 2% consistency. (Removes correlated D s mass uncertainty). More results expected soon! 18 Frank Porter, 17 July 23, International Europhysics Conference on High Energy Physics