DsJ mesons

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DsJ mesons

• Jolanta Brodzicka (KEK) for Belle
• QWG5, DESY
• 17-20 October 2007

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Outline
J. Brodzicka for Belle _at_ QWG5

• Introduction to cs multiplets
• Observation of new DsJ(2700) ?D0K in B?D0D0K
• Observation of Ds1(2536)?Dp-K
• Partial Wave Analysis of Ds1(2536)?DK0s
• Summary

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cs multiplets
J. Brodzicka for Belle _at_ QWG5

• Theory
• HQS based potential model predictions
  (Godfrey-Isgur 85)
• two doublets for orbitally excited L1 cs
  states
• 0, 1 (jq1/2) and 1, 2 (jq3/2)
• M(jq1/2), M(jq3/2) gt MDMK
• G(jq1/2) gtgt G(jq3/2)
  

• Experiment
• jq1/2 doublet
• 0 Ds0(2317)?Dsp0
• 1 Ds1(2460)?Dsp0
• jq3/2 doublet
• 1 Ds1(2536)?DK (Argus 89)
• 2 DsJ(2573)?DK (CLEO 94)
• their properties need to be measured
• higher orbital/radial excitations?

very narrow, masses below D()K ? dont match
the model predictions ? how to accommodate them
within current models?
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New DsJ meson in B?D0D0K
J. Brodzicka for Belle _at_ QWG5 hep-ex/0707.3491
(submitted to PRL)

• b?ccs tree process cs?D0K and cc?D0D0 states
  can contribute
• B?D0D0K signal identified using
• ?EEB-Ebeam , Ebeamvs/2 cms energy
  difference
• Mbc vE2beam-p2B beam-constrained mass
• S39940 for 449M BB used
• BF(B?D0D0K)(22.22.22.6-2.4) x10-4
• Dalitz plot and mass projections
• different from 3-body Ph. Space

points events from 1.5s ?E-Mbc signal box
background from sidebands
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Decomposition of B?D0D0K Dalitz plot
J. Brodzicka for Belle _at_ QWG5

• 2D ?E-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)gt3.85 GeV fitted with
Breit-Wigner ?(4160) reflection Ph. Space
(shapes from MC) exponential function (to
describe the threshold enhancement (?) )
DsJ(2700)
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DsJ(2700) ?D0K in B?D0D0K
J. Brodzicka for Belle _at_ QWG5

• Helicity angle distribution of DsJ(2700)
• (background free and efficiency corrected
• reflections from threshold and ?(4160)
  subtracted)
• J1 preferred 1?0-0- decay implies P-1
• Contributions to the observed mass spectra
• Most observed features well described

J0 ?2/ndf112/5 J1 ?2/ndf 11/5 J2
?2/ndf146/5
DsJ(2700) ?(3770) ?(4160) 3body
threshold component

(MC predicted shapes)
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DsJ(2700) interpretation
J. Brodzicka for Belle _at_ QWG5

• DsJ(2700)?D0K 1- state can be
• radial excitation 23S1
• (predicted by potential models at M2720GeV)
• chiral doubler state 1- to 1 Ds1(2536)
  (predicted from chiral symmetry
  considerations
• at M272110 MeV)
• BaBaR observed structure at M(DK)2.69GeV
  produced
• in ee- 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)
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Observation of Ds1(2536)?Dp-K
J. Brodzicka for Belle _at_ QWG5 hep-ex/0709.4184
(submitted to PRD)

• Known decay modes of Ds1(2536) DKs, D0K,
  Dspp-(evidence)
• Study of ee-?Ds1(2536)X using 462 fb-1,
• Ds1(2536)?Dp-K and Ds1(2536)?DKs
  (normalization mode)
• xPpDs1/pmaxgt0.8 in ee-cms pmaxvE2beam-M2Ds1
• Two-body mass spectra consistent with Phase Space

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Mixing of jq1/2 and jq3/2 states
J. Brodzicka for Belle _at_ QWG5

• HQET prediction for P-wave cs states
• 1(jq3/2)?DK pure D-wave decay Ds1(2536)?DK
• 1(jq1/2)?DK pure S-wave decay but
  Ds1(2460)?DK forbidden
• If HQET not exact mixing of S-D waves possible
• (by LS interaction, common decay channels,
  )
• Exp. knowledge on the mixing
• from BFs ratio of Ds1(2460) radiative decays
  Ds?/Ds?0.31 0.14
• switch from jqgt to 2S1LJ gt basis
  (from combined B decays
• 
  and
  ee- study by Belle)
• tan2(??0)0.8 0.4 where tan2?02 (no-mixing
  case)

• Measurement of mixing angle test of HQS, way
  to understand
• unusual properties of jq1/2 cs doublet

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Partial Wave Analysis of Ds1(2536)?DK0s
J. Brodzicka for Belle _at_ QWG5 hep-ex/0709.4184
(submitted to PRD)

• The decay described by a, ß, ? angels
• Prediction for 1 state
• in the helicity formalism
• ? helicity density matrix ?00 longitudinal
  polarization ?11 ?-1-1(1-?00)/2
• zvR? exp(i?)A10/A00 A10 , A00 ampl. of
  Ds helicity 1, 0
• A10(SD/v2)/v3 A00(S-v2D)/v3)
• 
  D, S partial-wave ampl. in Ds1 decay
  
• D/S v2(z-1)/(12z) vGD/GS exp(i?)

• If no angle integrated ? ?-dependent term
  survives

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Fit to angular distribution of
Ds1(2536)?DK0s
J. Brodzicka for Belle _at_ QWG5

• 3D maximum-likelihood fit with PDF
• Background PDF from M(DKs) sidebands,
  normalized
• fbck background fraction in M(DKs) signal
  region 9
• e(a,ß,?)/ltegt ? efficiency correction
• Fit result projections (bckgd subtracted and
  efficiency corrected)
• From ?2 of the fit goodness-of-fit probability
  60

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Results of Ds1(2536)?DK0s PWA
J. Brodzicka for Belle _at_ QWG5

• Fit results (include systematic errors)
• GS/GTOT 0.72 0.05 (?43.9 1.7)
• S-wave dominates in Ds1(2536)?DK, contradicts
  HQET
• Ds1(2460) and Ds1(2536) mix
• How to calculate the mixing angle ?? Help from
  theorists
• needed to translate measurement to the
  jq1/2, 3/2 states
• Ds1s helicity0 preferred
• Aligned production of jq3/2 states is
  predicted by HQET (?000.497).
• First full analysis for P-wave cs mesons
• CLEO integrated over ß in PWA of
  D1(2420)?Dp PLB 331, 236 PLB 340, 194.
• D1-D1 mixing angle measured from B?Dpp
  Dalitz plot analysis by Belle
• 
  (-0.100.030.020.02 rad) PRD
  69, 112002

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Summary
J. Brodzicka for Belle _at_ QWG5

• New info to cs multiplets
• new DsJ(2700)?D0K meson observed
• M2708911-10MeV G1082636-31MeV JP1-
• It opens a box of higher radial/orbital
  excitations of cs states
• new decay mode Ds1(2536)?Dp-K observed
• from PWA of Ds1(2536)?DKs (first full analysis
  for cs mesons)
• S-wave dominates GS/GTOT 0.72 0.05
• Ds1(2460) and Ds1(2536) mix
• longitudinal polarization ?00 0.4900.013
• ? Falk-Peskin HQET parameter w3/2 0.266
  0.019
• and to cc
• ?(3770)?D0D0 production in B decays confirmed
• ?(4160)?D0D0 production in B decays not
  significant

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Backup
J. Brodzicka for Belle _at_ QWG5

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Ds1 recoil mass study
J. Brodzicka for Belle _at_ QWG5

• Ds1(2536) recoil mass
• Mrec spectrum indicates 2-body reactions
• ee-?Ds1(2536)X, where XDs , Ds , higher
  Dss
• Mrec resolution 70MeV at 2GeV, 1/Mrec
  dependence
• 3D fits to angular distribution
• in bins of Mrec (R? and ? fixed)
• Polarization at low Mrec
• show structures expected for
• ee-?Ds1(2536)Ds , Ds1(2536)Ds

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• HQET Falk-Peskin parameter w3/2 (prob. of light
  quarks helicities)
• ?002/3(1- w3/2) w3/2 0.266 0.019
• (w3/2 lt0.24 _at_90CL from D2(2460)?Dp by
  ARGUS)

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