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D sJ mesons

D sJ mesons. Jolanta Brodzicka (KEK) for Belle QWG5, DESY 17-20 October 2007. Outline. J. Brodzicka for Belle @ QWG5. Introduction to c s multiplets Observation of new D sJ (2700) → D 0 K + in B + → D 0 D 0 K + Observation of D s1 (2536) → D + π - K +

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D sJ mesons

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  1. DsJ mesons Jolanta Brodzicka (KEK) for Belle QWG5, DESY 17-20 October 2007

  2. Outline J. Brodzicka for Belle @ QWG5 • Introduction to cs multiplets • Observation of new DsJ(2700) →D0K+ in B+→D0D0K+ • Observation of Ds1(2536)→D+π-K+ • Partial Wave Analysis of Ds1(2536)→D*+K0s • Summary

  3. cs multiplets J. Brodzicka for Belle @ QWG5 jq = sq + L, J = jq+ sQ L = 2 JP ….. 2+ DsJ(2573) jq = 3/2 BaBar CLEO ‘03 Belle L = 1 D*K 1+ Ds1(2536) mix? D K jq = 1/2 1+ Ds1(2460) 0+ D*s0(2317) spin-orbit tensor s-o spin-spin Ds* 1- jq = 1/2 L = 0 Ds 0- Theory: • HQS based potential model predictions: (Godfrey-Isgur ‘85) two doublets for orbitally excited L=1 cs states: • 0+, 1+ (jq=1/2) and 1+, 2+ (jq=3/2) • M(jq=1/2), M(jq=3/2) > MD+MK • Γ(jq=1/2) >> Γ(jq=3/2) Experiment: • jq=1/2 doublet 0+ : D*s0(2317)→Dsπ0 1+ : Ds1(2460)→D*sπ0 • jq=3/2 doublet 1+: Ds1(2536)→D*K(Argus ‘89) 2+: DsJ(2573)→DK(CLEO ‘94) their properties need to be measured • higher orbital/radial excitations? very narrow, masses below D(*)K →don’t match the model predictions → how to accommodate them within current models?

  4. New DsJ meson in B+→D0D0K+ J. Brodzicka for Belle @ QWG5 hep-ex/0707.3491 (submitted to PRL) ΔE Mbc new DsJ (4160) (3770) • b→ccs tree process; cs→D0K+ and cc→D0D0 states can contribute • B+→D0D0K+ signal identified using: ΔE=EB-Ebeam , Ebeam=√s/2 : cms energy difference Mbc= √E2beam-p2B : beam-constrained mass • S=399±40 for 449M BB used • BF(B+→D0D0K+)=(22.2±2.2+2.6-2.4) x10-4 • Dalitz plot and mass projections different from 3-body Ph. Space points: events from 1.5σ ΔE-Mbc signal box ■:background from sidebands

  5. Decomposition of B+→D0D0K+ Dalitz plot J. Brodzicka for Belle @ QWG5 fitted B signal yield ψ(4160) in ½ helicity distr. ψ(3770) • Non-coherent approach; possible interference effects included in syst. errors • 2D ΔE-Mbc fits in invariant mass bins → B signal extracted • Obtained background-free mass spectra used to estimate the resonance contributions: M(D0K+)for M(D0D0)>3.85 GeV fitted with: Breit-Wigner +ψ(4160) reflection + Ph. Space (shapes from MC) + exponential function (to describe the threshold enhancement (?) ) DsJ(2700)

  6. DsJ(2700) →D0K+ in B+→D0D0K+ J. Brodzicka for Belle @ QWG5 fitted B signal yield • Helicity angle distribution ofDsJ(2700): (background free and efficiency corrected; reflections from threshold and ψ(4160) subtracted) • J=1 preferred; 1→0-0- decayimpliesP=-1 • Contributions to the observed mass spectra • Most observed features well described J=02/ndf=112/5 J=12/ndf= 11/5 J=22/ndf=146/5 ■DsJ(2700)■ψ(3770)■ψ(4160)■3body■threshold component (MC predicted shapes)

  7. DsJ(2700) interpretation J. Brodzicka for Belle @ QWG5 • DsJ(2700)→D0K+ 1- state can be: • radial excitation 23S1 (predicted by potential models at M~2720GeV) • chiral doubler state 1- to 1+ Ds1(2536)(predicted from chiral symmetry considerations at M=2721±10MeV) • BaBaR observed structure at M(DK)~2.69GeV produced in e+e- continuum. Is that due to DsJ(2700)? • DsJ(2860) observed by BaBar not seen in our data. Its production in B decays suppressed by its high spin? BaBar Coll. PRL 97, 222001 (2006) Godfrey, Isgur PRD 32, 189 (1985) Close, Swanson PLB 647, 159 (2007) Nowak, Rho, Zahed Acta Phys. Polon. B 35, 2377 (2004)

  8. Observation of Ds1(2536)→D+π-K+ J. Brodzicka for Belle @ QWG5 hep-ex/0709.4184 (submitted to PRD) angular analysis performed for Ds1(2536)→D*+Ks sample • Known decay modes of Ds1(2536): D*+Ks, D*0K+, Dsπ+π-(evidence) • Study of e+e-→Ds1(2536)X using 462 fb-1, Ds1(2536)→D+π-K+ and Ds1(2536)→D*+Ks (normalization mode) • xP=pDs1/pmax>0.8 in e+e-cms pmax=√E2beam-M2Ds1 • Two-body mass spectra consistent with Phase Space

  9. Mixing of jq=1/2 and jq=3/2 states J. Brodzicka for Belle @ QWG5 θ θ0 • HQET prediction for P-wave cs states: • 1+(jq=3/2)→D*K pureD-wave decay: Ds1(2536)→D*K • 1+(jq=1/2)→D*KpureS-wave decay: but Ds1(2460)→D*K forbidden • If HQET not exact: mixing of S-D waves possible (by LS interaction, common decay channels, …) • Exp. knowledge on the mixing: • from BF’s ratio of Ds1(2460) radiative decays: D*sγ/Dsγ=0.31 ± 0.14 • switch from |jq>to |2S+1LJ >basis (from combined B decays and e+e- study by Belle) • tan2(θ+θ0)=0.8 ± 0.4 where tan2θ0=2 (no-mixing case) • Measurement of mixing angle: test of HQS, way to understand • unusual properties of jq=1/2 cs doublet

  10. Partial Wave Analysis of Ds1(2536)→D*+K0s J. Brodzicka for Belle @ QWG5 hep-ex/0709.4184 (submitted to PRD) • The decay described by α, β, γ angels • Prediction for 1+ state in the helicity formalism: • ρ: helicity density matrix ρ00: longitudinal polarizationρ11=ρ-1-1=(1-ρ00)/2 • z=√RΛ exp(iξ)=A10/A00A10 , A00: ampl. of D*‘s helicity= ±1, 0 • A10=(S+D/√2)/√3 A00=(S-√2D)/√3) D, S: partial-wave ampl. in Ds1 decay D/S= √2(z-1)/(1+2z) =√ΓD/ΓS exp(iη) • If no angle integrated → ξ-dependent term survives

  11. Fit to angular distribution of Ds1(2536)→D*+K0s J. Brodzicka for Belle @ QWG5 • 3D maximum-likelihood fit with PDF: • Background PDF: from M(D*+Ks) sidebands, normalized • fbck: background fraction in M(D*+Ks) signal region: ~9% • ε(α,β,γ)/<ε> → efficiency correction • Fit result projections (bckgd subtracted and efficiency corrected): • From χ2 of the fit: goodness-of-fit probability: 60%

  12. Results of Ds1(2536)→D*+K0sPWA J. Brodzicka for Belle @ QWG5 • Fit results (include systematic errors): ΓS/ΓTOT = 0.72 ± 0.05 (η=43.9 ± 1.7°) • S-wave dominates in Ds1(2536)→D*K, contradicts HQET • Ds1(2460) and Ds1(2536) mix • How to calculate the mixing angle θ? Help from theorists needed to translate measurement to the jq=1/2, 3/2 states Ds1’s helicity=0 preferred Aligned production of jq=3/2 states is predicted by HQET (ρ00~0.497). • First full analysis for P-wave cs mesons CLEO integrated over βin PWA of D1(2420)→D*πPLB 331, 236; PLB 340, 194. D1’-D1 mixing angle measured from B→D*ππDalitz plot analysis by Belle (-0.10±0.03±0.02±0.02 rad) PRD 69, 112002

  13. Summary J. Brodzicka for Belle @ QWG5 • New info to cs multiplets: • new DsJ(2700)→D0K+ meson observed: M=2708±9+11-10MeV Γ=108±26+36-31MeV JP=1- It opens a box of higher radial/orbital excitations of cs states • new decay mode: Ds1(2536)→D+π-K+observed • from PWA of Ds1(2536)→D*+Ks(first full analysis for cs mesons): • S-wave dominates: ΓS/ΓTOT = 0.72 ± 0.05 • Ds1(2460) and Ds1(2536) mix • longitudinal polarization: ρ00 = 0.490±0.013 → Falk-Peskin HQET parameter: w3/2 = 0.266 ± 0.019 • …and to cc • Ψ(3770)[→D0D0] production in B decays confirmed • Ψ(4160)[→D0D0] production in B decays not significant

  14. J. Brodzicka for Belle @ QWG5 Backup

  15. Ds1 recoil mass study J. Brodzicka for Belle @ QWG5 • Ds1(2536) recoil mass: • Mrec spectrum indicates 2-body reactions: e+e-→Ds1(2536)X, where X=Ds ,D*s , higher D**s’s • Mrec resolution: ~70MeV at 2GeV, 1/Mrec dependence • 3D fits to angular distribution in bins of Mrec (RΛ and ξfixed) • Polarization at low Mrec: show structures expected for: e+e-→Ds1(2536)Ds ,Ds1(2536)D*s

  16. HQET Falk-Peskin parameter w3/2 (prob. of light quark’s helicities) • ρ00=2/3(1- w3/2) w3/2 = 0.266 ± 0.019 • (w3/2<0.24 @90%CL from D2*(2460)→Dπ by ARGUS)

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