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New Resonances a t Belle Jolanta Brodzicka INP Kraków For the Belle Collaboration

New Resonances a t Belle Jolanta Brodzicka INP Kraków For the Belle Collaboration XL IV Cracow School of Theoretical Physic s , Zakopane May 28 - June 6 , 2004. Topics : heavy-light mesons cs : D SJ in e + e -  cc continuum and B exclusive decays

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New Resonances a t Belle Jolanta Brodzicka INP Kraków For the Belle Collaboration

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  1. New Resonances at Belle Jolanta Brodzicka INP Kraków For the Belle Collaboration XLIV Cracow School of Theoretical Physics,Zakopane May 28 - June 6, 2004 • Topics : • heavy-light mesons • cs : DSJ in e+ e- cc continuum and B exclusive decays • cu : D** in B  D(*) + - decays • charmonium-like state X(3872)

  2. The Belle Collaboration A World-Wide Activity: ~300 People from ~50 Institiutions Jolanta Brodzicka, INP Kraków , Belle Coll.

  3. KEK-B Factory • KEKB : Asymmetric e+e- collider • Two separate rings • e+ (LER) : 3.5 GeV • e- (HER) : 8.0 GeV • CM energy : 10.580 GeV at (4S) • e+e-  (4S)  BB • Parameters • 3016 m circumference • ±11 mrad crossing angle • History: Physics run since June 1999 • Luminosity peak:1.3x1034 cm-2s-1 • (achieved: 20May2004) • Integrated Luminosity: 250 fb-1 • ~ 260 x 10 6 BB • ~ 300 x 10 6 cc continuum events Jolanta Brodzicka, INP Kraków , Belle Coll.

  4. Belle Detector Aerogel Cherenkov Counter • Event reconstruction •  Charged track  Central Drift Chamber (CDC)  Silicon Vertex Detector (SVD) •  Electron and photon  Electromagnetic Calorimeter (ECL) Time of Flight Counter Central Drift Chamber Particle identification  K/ separation  CDC : dE/dx  Aerogel Cherenkov Counter (ACC)  Time of Flight Counter (TOF)  electron identification  ECL  KL and  identification  KL and muon detector (KLM) Vertexing  SVD SC Solenoid 1.5T Silicon Vertex Detector KL /Detector Electromagnetic Calorimeter Jolanta Brodzicka, INP Kraków , Belle Coll.

  5. Inconsistent with model predictions. Expected: broad states with masses: 2.48 2.53 GeV (above D(*)K threshold) New observations at B-Factories • BaBarwith 91 fb-1on/off (4S)discovered resonance • DSJ(2317)  DS±0 • isospin violating decay , narrow state (  < 10MeV ) • BaBaralso sawpeak in DS 0 mass distribution@ ~2460 MeV • Interpreted as cross-feed from 2317(DS from 2317 + random  ) • CLEO (13.5 fb-1)confirmed DSJ(2317) establishedDSJ(2463) DS *±0 • Belle(87 fb-1)saw both : DSJ(2317) DSJ(2457) statesin cc continuum • & in B decays Topic of this talk • Interpretations: • DSJ(2317) DSJ(2457)identified with :0+ , 1+ orbitally excited P-wave cs states • more exotic assignments :DK molecule, multiquark state, mixing P-wave cs states with 4-quark csqq states ( masses shifted below D(*)K) Jolanta Brodzicka, INP Kraków , Belle Coll.

  6. Q q Angular momentum of thelight quark Total spin of a meson Potential Model for Q q Godfrey-Isgur(1985) • Basic hypotheses of constituent quark model : • mesons : valence-quark configuration • dynamics described by a Hamiltonian: • relativized • confinement with running s • one gluon exchange dominates at short distance VQq Hconf + Hspin-spin(color-hyperfine) + Hspin-orbit(1-gluon-exch) + Hspin-orbit(Thomas precession) Inter-quark potential : Heavy Quark Symmetry:mQ   Q at rest (no chromomagnetic field, static source of chromoelectric field) , Q decouples from q (~hydrogen atom) dynamics of the q  meson properties separately conserved Jolanta Brodzicka, INP Kraków , Belle Coll.

  7. spin-orbit spin-spin relativistic correction to HQ S : an expansion in powers of 1/mQ hyperfine splitting Predictions for cu and cs mesons based on Heavy Quark Symmetry • L = 1 Parity+ • jq= ³/2J =2 • J = 1 • jq= ½J = 1 • J = 0 • L = 0Parity - • jq = ½ J= 1 • J= 0 DSJ(2573) DS1(2536) D’S1 2.53GeV DS 02.48GeV D*2(2462) D1 (2421) D’1 2.44GeV D*0 2.40GeV Missing doublets till last summer D* (2007) D (1865) Ds* (2112) Ds (1968) • P-wave states withjq= ½ : expected to be broad (S-wave decays) •  difficult to identify experimentally(jq= ³/2states: narrow) • Also some predictions that: m(jq= ½ ) > m(jq= ³/2 ) Jolanta Brodzicka, INP Kraków , Belle Coll.

  8. DSJ(2317) @ Belle • data sample: 87 fb-1 • e+e-  cc  Ds± 0 X (inclusively-produced) • Ds±  (K- K+)±p* (Ds ±0 ) > 3.5 GeV (p in CMS)(to reduce combinatorial background) DK threshold Fitted signal: 761  44 (stat)30 (syst) Events/5MeV 0/DS± sidebands M( DS 0) - M( DS ) GeV/c 2 M( DS 0 ) - M( DS ) GeV/c 2 Small peak : feed-down from DSJ(2457) M(DSJ(2317)) = 2317.2 ± 0.5(stat) ± 0.9(syst) MeV/c 2  < 4.6 MeV/c 2 (90% C.L.) Jolanta Brodzicka, INP Kraków , Belle Coll.

  9. DSJ(2457) @ Belle • e+e-  cc  Ds*± 0 X ( Ds*± 0inclusively produced ) • Ds*±  Ds± Ds±  (K- K+)+ p* (Ds*±0 ) > 3.5 GeV Fitted signal: 12625(stat)12 (syst) Events/5MeV DS*± sideband M( D*S 0 ) - M( D*S ) GeV/c 2 M( D*S 0) - M( D*S ) GeV/c 2 M(DSJ(2457)) = 2456.5 ± 1.3(stat) ± 1.3(syst) MeV/c 2 Sideband-subtracted distribution  < 5.5 MeV/c 2 (90% C.L.) • „Peaking” background sources: • Signal feeddown from DSJ(2317)+random soft  • „Broken”DSJ(2457) signal : Ds* with „bad”  Test of nature ofDSJ : search for other decay modes Jolanta Brodzicka, INP Kraków , Belle Coll.

  10. BR( DSJ(2457) DS± ) BR( DSJ(2457) DS± + - ) BR( DSJ(2457)  Ds*± 0 ) BR( DSJ(2457)  Ds*± 0 ) = 0.14 ± 0.04(stat) ± 0.02(syst) = 0.55 ± 0.13(stat) ± 0.08(syst) Decay modes ofDSJ DSJ(2457) DS± DSJ(2457) DS± + - DSJ(2317) region 59  11 152  18 DS1 (2536) Events/5MeV Events/3MeV M( DS ) - M( DS ) GeV/c 2 M( DS +-) - M( DS ) GeV/c 2 Dipion mode 1sttime observed (D’S1assumption: 0.62 ) (D’S1assumption: 0.16 ) Godfrey,Phys.Lett.B 568, 254 (2003) DSJ(2457) :JP 0+ ,0- favours JP= 1+ DSJ(2317) :favours JP= 0+ • No signal observed in: • DSJ(2457) Ds*± , Ds± 0 • DSJ(2317) Ds± , Ds*± , DS± + - From conservation of angular mom. and parity Jolanta Brodzicka, INP Kraków , Belle Coll.

  11. - DSJ in cc continuum - summary • Belle observed DSJ(2317) DS±0 • and DSJ(2457)DS *±0 • inclusively produced in e+e- cc continuum • radiative and dipion decay modes of DSJ(2457)observed • the spin-parities 0+(DSJ(2317)) and 1+(DSJ(2457)) are favoured Jolanta Brodzicka, INP Kraków , Belle Coll.

  12. DSJin B exclusive decays Motivations: • Assignments ofDSJ(2317)andDSJ(2457)being • orbitally excited cs mesons need confirmation • IfDSJ(2317)andDSJ(2457)arecs states : • can be observed inB  DDsJdecays • expected BF ~ 10-2 10-3 , quite large • States cs with j q= ½ “easier” produced in B decays than those with j q= ³/2 (HQET) • States produced in B decay can be polarized: from angular distributions  J P • In B decays : background reduction Tree type diagram processes Jolanta Brodzicka, INP Kraków , Belle Coll.

  13. Method of full B reconstruction • Experimental conditions: e+e-  (4S)  BB m  (mB+mB) • For B decay to specific final state: B  f1 f2 …fn In(4S) frame Energy-Momentum conservation: Kinematical constraints are used • Kinematical Variables: • Energy difference • Beam-constrained • mass resolution improvement, background separation Jolanta Brodzicka, INP Kraków , Belle Coll.

  14. J=2 hypothesis J=1 hypothesis B  DDsJdecays data sample: 115 fb-1 Signal extracted in E, Mbc and M(DSJ) Plot one of them with cuts on the others Reconstructed modes: B+  D0 DsJ+ B0  D- DsJ+ Both isospin related modes Events/10MeV E GeV M( DSJ ) GeV/c 2 DS±decay angle of in DSJ (2457) DS± (B  D DSJ ) Jolanta Brodzicka, INP Kraków , Belle Coll.

  15. BR(DDSJ)xBR( DSJ(2457) DS± ) BR(DDSJ)xBR( DSJ(2457)  Ds*± 0 ) DSJin exclusive B decays – summary BR(BDDSJ)  BR(DSJ) comparison: 0.4 • first observation of DSJ states in B decayin Belle • no new DSJ decay modes in comparison to inclusive production • masses and widths consistent • DSJ (2457) angular analysis consistent with J=1 • measured BR’s do not exclude cs states assignments Jolanta Brodzicka, INP Kraków , Belle Coll.

  16. New D**0 states expected decay modes: D- + , D*- + • data sample : 60 fb-1 • Dalitz analysis for : • B+ D- + + (~1100 signal events) andB+ D*- + + (~600 events) both with good S/B • unbinned likelihood fit performedwith signal density function: • S (M 12, M22 ) =Ai exp(ii ) BWi (M1 2, M2 2 ) + Aexp(i) 2  R(M2) • coherent sum of the amplitudes of D** states which can contribute and phase space term • convolution with experimental resolution Jolanta Brodzicka, INP Kraków , Belle Coll.

  17. D**0mesons Dalitz plot projections with fit results Background M ( D min) GeV/c 2 M ( D min) GeV/c 2 Background M ( D* min) GeV/c 2 M ( D* min) GeV/c 2 First observation of D*0 and D1’0 , Belle Coll. Jolanta Brodzicka, INP Kraków

  18. D**0- summary • Belle observed for the first timebroadD*0and D1’0states in B decays • (observed also by FOCUS, poor agreement in measured masses) • Identified as 0+and 1+orbitally excited cu doublet (withj q= ½) • Narrow 1+ , 2+ states: D10and D2* 0 also seen • (already observed by CLEO) • Masses and widths of four D** states were measured Jolanta Brodzicka, INP Kraków , Belle Coll.

  19. Measured masses versus model predictions • In cu spectrum: masses of D, D*,D** consistent with model expectations • In cs case: masses of newDSJ (2317) andDSJ (2457) inconsistent Model expectation: M(cs ) – M(cu)  100 MeV Chiral symmetry broken chiral partners split off (states with opposite parity) DSJ (2317) andDSJ (2457) interpreted aschiral partners of DS andD*S ?  Nowak’s talk Jolanta Brodzicka, INP Kraków , Belle Coll.

  20. Discovery of X(3872) • Belle data sample: 140 fb-1 • in B decay B ± K± + - J/J/  l+ l- For B signal extracted in E, Mbc M( + - l+ l- ) - M(l+ l- ) GeV M( + - l+ l - ) - M(l+ l - ) New state is not reflection from any known state new narrow charmonium-like state : X(3872)  J/ + - Jolanta Brodzicka, INP Kraków , Belle Coll.

  21. X(3872) • Signal B ±  X(3872)K± extracted in E, Mbc and M( J/ + -) • Plot one of them with cut on the others • Simultaneous fit in 3 variables S = 35.7 6.8 (10 ) Events/5MeV Events/5MeV Events/15MeV Mbc GeV E GeV M ( J/ + - ) GeV MX = 3872.0 ± 0.6(stat) ± 0.5(syst) MeV X < 2.3 MeV(90% C.L.) • MX > M(D + D)open-charm decay possible, why so narrow ? • X produced in B decays: J cannot be high • Is it charmonium state? • One of the unobserved higher charmonium states 13DJ11D2 23P1 21P1? • (predicted masses @ X mass region) • MX  M(D0 + D*0) loosely boundedmolecular or hybrid state? Jolanta Brodzicka, INP Kraków , Belle Coll.

  22.  (3Dc 2 c1)  2.  (3Dc 2  J/ + - )  (X(3872)   c1)  (X(3872)  J/ + - )  0.89 (90% C.L.)  (X(3872)   c2)  (X(3872)  J/ + - )  1.1(90% C.L.) Properties of X(3872) • Checking hypothesis that X(3872) is charmonium state •  radiative X decays should be observed (Eichten,Lane,Quigg) 3Dc 2 3Dc 3?X(3872)  c1,  c2 Theory: • B ± K±  c1c1(1P)  J/ Events/4MeV Events/8MeV M ( c1) GeV No signal in X(3872) region Mbc GeV • B ± K±  c2 c2(1P)  J/ Events/10MeV Events/5MeV M ( c2) GeV Mbc GeV 3Dc 2 &3Dc 3 ruled out Jolanta Brodzicka, INP Kraków , Belle Coll.

  23.  ( 23P1  J/ )  ( 23P1  J/ + - ) Properties of X(3872) 23P1?X(3872)  J/ B ± K±  J/ Theory:  11keV / 0.3keV  30 Absence of X(3872) ’c1 (23P1 )ruled out M ( J/) - M (J/) GeV h’c (21P1 ) ? Prediction for 1+ :  1- cos2 (J/) J/ decay angle in X(3872) J/ + -(B  K X(3872) ) cos (J/) h’c1 (21P1 )ruled out Jolanta Brodzicka, INP Kraków , Belle Coll.

  24. X(3872) – summary • New unexpected state X(3872) observed by Belle • (also seen at Fermilab in pp collisions and BaBar ) • Still no obvious charmonium assignment • Is it D0 D*0 molecule? MX = 3872.0 ± 0.6(stat) ± 0.5(syst) MeV X < 2.3 MeV(90% C.L.) Jolanta Brodzicka, INP Kraków , Belle Coll.

  25. Summary • Many charm results from Belle. • Some of them • unexpected or/and inconsistentwith theoretical expectations. • B-Factory is a Charm Factory, too. • In aditionB decays are good and clear ground • to study charm spectroscopy. Jolanta Brodzicka, INP Kraków , Belle Coll.

  26. Jolanta Brodzicka, INP Kraków , Belle Coll.

  27. Dsmesons Dmesons L=1 L=1 Jolanta Brodzicka, INP Kraków , Belle Coll.

  28. Jolanta Brodzicka, INP Kraków , Belle Coll.

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