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A.Drutskoy, University of Cincinnati

Properties of the D sJ states. A.Drutskoy, University of Cincinnati. First Meeting of the APS Topical Group on Hadronic Physics. October 24-26, 2004, Fermilab, Batavia.

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A.Drutskoy, University of Cincinnati

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  1. Properties of the DsJ states A.Drutskoy, University of Cincinnati First Meeting of the APS Topical Group on Hadronic Physics October 24-26, 2004, Fermilab, Batavia A. Drutskoy APS Topical Group Meeting on Hadronic Physics October 24-26, 2004, Fermilab

  2. Outlook 1. Production of DsJ mesons in continuum _ 2. Improved measurement of B -> DsJ D(*) decays _ _ - + 0 + 3. First study of B -> DsJ K and DsJp decays 4. Conclusions Last two measurements areBelle preliminary. A. Drutskoy APS Topical Group Meeting on Hadronic Physics October 24-26, 2004, Fermilab

  3. Full statistics at U(4S) ~253 fb-1 275 x106 BB pairs Partial statistics includes ~140 fb-1 or 152 x106 BB pairs A. Drutskoy APS Topical Group Meeting on Hadronic Physics October 24-26, 2004, Fermilab

  4. DsJ meson production in continuum + + BaBar first observed DsJ(2317) -> Dspo decay mode in e+e- continuum. No evidence for DsJ(2317) -> Dsg, Ds g and Dsgg was found. CLEO confirmed observed DsJ(2317) signal and established DsJ(2460) signal. Signal widths were consistent with detector resolution. * + + Belle confirmed BaBar and CLEO results. Decay modes observed are DsJ(2317) -> Dsp0, DsJ(2460) -> Ds * p0 and DsJ(2460) -> Dsg. + + + + + + Belle Belle Belle A. Drutskoy APS Topical Group Meeting on Hadronic Physics October 24-26, 2004, Fermilab

  5. DsJ meson spectroscopy In the heavy quark limit, the total angular momentum of the light quark Jq is a good quantum number. This leads to spectroscopy with separated Ds meson spin-doublets: (0-, 1-), (0+,1+), (1+,2+). * Ds DsJ(2460) Ds DsJ(2317) Measured massesof DsJ(2317) and DsJ(2460) are significantly lower than predictions from potential models. Widths are consistent with zero in contrast to expectations. + + Large theoretical efforts to explain narrowDsJ(2317)andDsJ(2460)resonances:DK threshold effect, chiral partners, four-quark states? A. Drutskoy APS Topical Group Meeting on Hadronic Physics October 24-26, 2004, Fermilab

  6. _ Improved measurement of BD DsJ decays _ B -> D DsJ processes are described by conventional tree diagram. D- and D0 decay modes are combined in figures. 275x106 BB pairs. Masses: 2320.0±1.1±2.0and2459.5±0.9±2.0MeV; Width consistent with resolution DsJ(2317)Ds0 DsJ(2460) Ds*0 DsJ(2460) Ds A. Drutskoy APS Topical Group Meeting on Hadronic Physics October 24-26, 2004, Fermilab

  7. _ Observation of BD* DsJ decays _ Belle also measured B -> D* DsJ decays (BaBar recently reported these Bf). - D* and D*0 decay modes are combined in figures. 274x106 BB pairs. DsJ(2317)Ds0 DsJ(2460) Ds*0 DsJ(2460) Ds A. Drutskoy APS Topical Group Meeting on Hadronic Physics October 24-26, 2004, Fermilab

  8. _ _ Combined (D0 and D-) results for B -> DsJ D decays Decay channel Bf, 10- 4 Significance _ B  D DsJ(2317) [Dsp0] 10.1  1.5  3.0 9.5s B  D DsJ(2317) [Ds*g] 4.0-1.4+1.5 (<8.4) 3.5s B  D DsJ(2460) [Ds*p0] 14.8-2.5+2.8  4.4 8.6s B  D DsJ(2460) [Dsg] 6.4  0.8  1.9 11s B  D DsJ(2460) [Ds*g] 2.6-1.0+1.1 (<5.7) 3.0s B  D DsJ(2460) [Dsp+p-] 1.0-0.4+0.5 (<2.3) 2.6s B  D DsJ(2460) [Dsp0] 0.2-0.5+0.7 (<1.7) -- B  D* DsJ(2317) [Dsp0] 3.1-1.7+2.1 (<8.5) 2.0s B  D* DsJ(2460) [Ds*p0] 28.7-6.4+7.4  8.6 6.9s B  D* DsJ(2460) [Dsg] 12.7-2.0+2.2  3.8 10s _ _ _ _ _ _ _ _ _ Belle branching fractions with D* meson are about two times smaller than those obtained by BaBar. _ Measured BF an order of magnitude smaller than in B-> DsD decays with pseudoscalar Ds. Theory : similar rates for Ds, Ds*, DsJ(2317),DsJ(2460)? A. Drutskoy APS Topical Group Meeting on Hadronic Physics October 24-26, 2004, Fermilab

  9. _ Combined (D0 and D-) results for B -> DsJ D decays Bf(DsJ(2460)Ds) / Bf(DsJ(2460)  Ds* 0) = 0.43  0.08  0.04 Bf(DsJ(2460)  Ds0) / Bf(DsJ(2460)  Ds* 0) < 0.10 @90%CL Bf(DsJ(2460)  Ds+-) / Bf(DsJ(2460)  Ds* 0) < 0.13 @90%CL Bf(DsJ(2460)  Ds* ) / Bf(DsJ(2460)  Ds) < 0.76 @90%CL Bf(DsJ(2317)  Ds* ) / Bf(DsJ(2317)  Ds0) < 0.70 @90%CL J=1 J=1 J=0 J=2 DsJ(2460)  Ds* g DsJ(2317)  Dsp0 J=0 c2/ndf=3/8 ; J=1 c2/ndf=38/8 J=1 c2/ndf=4/8 ; J=2 c2/ndf=89/8 Data agree with Jp=0+ for DsJ(2317) and Jp=1+ for DsJ(2460) A. Drutskoy APS Topical Group Meeting on Hadronic Physics October 24-26, 2004, Fermilab

  10. _ _ + - B0-> DsJ K- and B0-> DsJp+ decays DsJ(2317) and DsJ(2460) mesons are selected to search for B->DsJ K and B>DsJp decays. W exchange diagram Final state interactions Tree, 4-quark DsJ content + The DsJ K– final state has a completely different quark content than original B meson. Within factorization approach, Cabbibo-Kobayashi-Maskawa matrix element Vub can be obtained from ratio: Bf(B-> Dsp+) / Bf(B-> Ds D+) = (0.424+0.041) x |Vub/Vcb|2 Measured branching fractions (Belle): Bf(B0-> Ds K-)= (2.93+0.55+0.79)x10-5 Bf(B0-> Dsp+)=(1.94+0.47+0.52)x10-5 _ + _ - Studies of B->DsJD, B->DsJK and B-> DsJp decays are important to understand the nature of DsJ mesons (2- quark or 4- quark DsJ content ?). A. Drutskoy APS Topical Group Meeting on Hadronic Physics October 24-26, 2004, Fermilab

  11. _ _ + - First study of B0->DsJ K- and B0-> DsJp+ decays + + DsJ(2317)+ -> Ds p0 , DsJ(2460)+ -> Dsg 152 x106 BB pairs, L= 140fb-1 + Ds-> fp+, K*0K+, KSK+ 6.8 s DsJ(2317) K- DsJ(2317) K- DsJ(2317) p+ DsJ(2317) p+ DsJ(2460) K- DsJ(2460) K- DsJ(2460) p+ DsJ(2460) p+ A. Drutskoy APS Topical Group Meeting on Hadronic Physics October 24-26, 2004, Fermilab

  12. _ - + Study of B0->DsJ K- and DsJp+ decays Fit to mass difference DM = M(DsJ)-M(Ds) (mass and width are allowed to float): Data: DM(DsJ(2317))=(351.2 ± 1.6) MeV/c2 MC: DM(DsJ(2317))=(348.5 ± 0.3) MeV/c2 (2317.5) Resolution s: Data: s=(6.0 ± 1.2)MeV/c2MC: s=(6.1 ± 0.2)MeV/c2 Flat -> Jp=0+ Obtained branching fraction and upper limits: _ Bf(B0->DsJ(2317)+ K-) x Bf(DsJ(2317)+->Ds+p0) = (5.3+1.5 ±0.7 ±1.4)x10-5 -1.3 _ Measured B0-> DsJ(2317)+ K- branching fraction is of the same order as B0->D+s K- branching fraction and at least 2 times larger than that for B0->DsJ(2460)+K- decay (Bf(DsJ(2460)->Dsg)~30%) -> unexpected !!! _ _ A. Drutskoy APS Topical Group Meeting on Hadronic Physics October 24-26, 2004, Fermilab

  13. Why is that? Bf(B0->DsJ(2317)+ D-) x Bf(DsJ(2317)+->Ds+p0) = (10.3+2.3 ± 3.1)x10-4 -2.0 Bf(B0->Ds+ D-) = (8.0± 3.0)x10-3 _ Bf(B0->DsJ(2317)+ K-) x Bf(DsJ(2317)+->Ds+p0) = (5.3+1.5 ± 0.7 ± 1.4)x10-5 -1.3 _ Bf(B0->Ds+ K-) = (2.93± 0.55 ± 0.79)x10-5 Theoretical expectations (naïve): Bf(B0->Ds+ M) ~ 1, if DsJ is two-quark state. for M = D, K, p = Bf(B0->DsJ(2317)+ M) ~ 10, if DsJ is four-quark state. Four-quark tree diagram (for DsJ+ K- decay) can change this ratio. Probably too naïve… Ask theorists to explain this. A. Drutskoy APS Topical Group Meeting on Hadronic Physics October 24-26, 2004, Fermilab

  14. Conclusions _ n Decays B -> DsJ D(*)were measured with improved accuracy. Obtained branching fractions are of order of magnitude smaller than those with a pseudoscalar Ds . Angular distributions indicate that the DsJ(2317)is0+ and the DsJ(2460) is 1+. _ _ + n B0 -> DsJ K- and DsJp+ were studied for the first time. The branching fraction for B0-> DsJ(2317)+ K- is of the same order asB0->Ds K-branching fraction and more than two times larger than that forB0->DsJ(2460)+K- decay(assuming Bf(DsJ(2460)->Dsg)~30%). _ _ + _ More experimental measurements are required to understand the nature of DsJ mesons. n A. Drutskoy APS Topical Group Meeting on Hadronic Physics October 24-26, 2004, Fermilab

  15. Background slides

  16. Procedures to extract B signal yield Two almost independent variables MB and DE can be used to select B meson signal: * MB = (Ebeam)2 – (S Pi)2 DE = SEi - Ebeam * Methods to extract B signal yield: 1) Cut on MB and fit to DE 2) Cut on DE and fit to MB 3) Double dimensional fit to MB and DE distribution 4) If B->P1P2P3: cut DEand MB box and look at resonant structures in M(P1P2) mass distribution. A. Drutskoy APS Topical Group Meeting on Hadronic Physics October 24-26, 2004, Fermilab

  17. Continuum Suppression • To separate spherical BB events from jet-like continuum events, topological variables are used: • Second Fox-Wolfram moment • Super Fox-Wolfram • (six modified Fox-Wolfram moments, Fisher discriminant) • 3) Angle between B meson and • beam axis direction • 4) Angle between thrusts of • selected B meson particles and all other particles in event • Likelihood ratio includes all info. A. Drutskoy APS Topical Group Meeting on Hadronic Physics October 24-26, 2004, Fermilab

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