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New Resonances at Belle Jolanta Brodzicka INP Kraków For the Belle Collaboration XLIV Cracow School of Theoretical Physics, Zakopane May 28 - June 6, 2004.

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Presentation on theme: "New Resonances at Belle Jolanta Brodzicka INP Kraków For the Belle Collaboration XLIV Cracow School of Theoretical Physics, Zakopane May 28 - June 6, 2004."— Presentation transcript:

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 heavy-light mesons cs : D SJ in e + e - cc continuum and B exclusive decays cs : D SJ in e + e - cc continuum and B exclusive decays cu : D** in B D ( * ) + - decays cu : D** in B D ( * ) + - decays charmonium-like state X(3872) charmonium-like state X(3872)

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

3 KEK-B Factory Jolanta Brodzicka, INP Kraków KEKB : Asymmetric e + e - collider Two separate ringsTwo separate rings e + (LER) : 3.5 GeV e - (HER) : 8.0 GeV CM energy : GeV at (4S) CM energy : GeV at (4S) e+e- BB e+e- (4S) BB Parameters Parameters 3016 m circumference3016 m circumference ±11 mrad crossing angle±11 mrad crossing angle History: Physics run since June 1999 History: Physics run since June 1999 Luminosity peak: 1.3x10 34 cm -2 s -1 Luminosity peak: 1.3x10 34 cm -2 s -1 (achieved: 20May2004 ) (achieved: 20May2004 ) Integrated Luminosity : 250 fb -1 Integrated Luminosity : 250 fb -1 ~ 260 x 10 6 BB ~ 260 x 10 6 BB ~ 300 x 10 6 cc continuum events ~ 300 x 10 6 cc continuum events, Belle Coll.

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

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

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

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

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

9 Jolanta Brodzicka, INP Kraków D SJ ( 2457 Belle M( D * S 0 ) - M( D * S ) GeV/c 2 M( D * S 0 ) - M( D * S ) GeV/c 2 M( D * S 0 ) - M( D * S ) GeV/c 2 Events/5MeV e+e- cc D s * 0 X ( D s * 0 inclusively produced ) e+e- cc D s * ± 0 X ( D s * ± 0 inclusively produced ) D s * D s ± D s ± ( K - K + ) + p* ( D s * ± 0 ) > 3.5 GeV D s * ± D s ± D s ± ( K - K + ) + p* ( D s * ± 0 ) > 3.5 GeV Peaking background sources: Signal feeddown from D SJ (2317)+ random soft Broken D SJ (2457) signal : D s * with bad Fitted signal: (stat) 12 (syst) M( D SJ (2457) ) = ± 1.3(stat) ± 1.3(syst) MeV/c 2 < 5.5 MeV /c 2 (90% C.L.) < 5.5 MeV /c 2 (90% C.L.) D S * ± sideband Sideband-subtracted distribution Test of nature of D SJ : search for other decay modes, Belle Coll.

10 59 11 Jolanta Brodzicka, INP Kraków Decay modes of D SJ M( D S + - ) - M( D S ) GeV/c 2 M( D S + - ) - M( D S ) GeV/c 2 M( D S ) - M( D S ) GeV/c 2 Events/3MeVEvents/5MeV D SJ (2457) D S + - D SJ (2457) D S ± D SJ (2457) D S D SJ (2457) D S ± BR( D SJ (2457) D S ) BR( D SJ (2457) D S ± ) BR( D SJ (2457) D s * 0 ) BR( D SJ (2457) D s * ± 0 ) = 0.55 ± 0.13(stat) ± 0.08(syst) No signal observed in: No signal observed in: D SJ (2457) D s *, D s 0 D SJ (2457) D s * ±, D s ± 0 D SJ (2317) D s, D s *, D S + - D SJ (2317) D s ±, D s * ±, D S ± + - D SJ (2457) : J P 0 +, 0 - favours J P = 1 + D SJ (2317) : favours J P = 0 + From conservation of angular mom. and parity D S1 (2536) D SJ (2317) region Dipionmode 1 st time observed ( D S1 assumption: 0.62 ) ( D S1 assumption: 0.16 ) Godfrey,Phys.Lett.B 568, 254 (2003), Belle Coll. BR( D SJ (2457) D S + - ) BR( D SJ (2457) D S ± + - ) BR( D SJ (2457) D s * 0 ) BR( D SJ (2457) D s * ± 0 ) = 0.14 ± 0.04(stat) ± 0.02(syst)

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

12 Assignments of D SJ (2317) and D SJ (2457) being Assignments of D SJ (2317) and D SJ (2457) being orbitally excited cs mesons need confirmation orbitally excited cs mesons need confirmation If D SJ (2317) and D SJ (2457) are cs states : If D SJ (2317) and D SJ (2457) are cs states : can be observed in B D D sJ decays can be observed in B D D sJ decays expected BF ~ , quite large expected BF ~ , quite large States cs with j q = ½easier produced in B decays than those with j q = ³/ 2 (HQET) 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 States produced in B decay can be polarized: from angular distributions J P In B decays : background reduction In B decays : background reduction D SJ in B exclusive decays Jolanta Brodzicka, INP Kraków Motivations:, Belle Coll. Tree type diagram processes

13 Kinematical Variables: Energy differenceEnergy difference Beam-constrainedBeam-constrained mass mass Jolanta Brodzicka, INP Kraków K inematical constraints are used For B decay to specific final state: B f 1 f 2 … f n For B decay to specific final state: B f 1 f 2 … f n Experimental conditions: Method of full B reconstruction e+e- BB m e+e- (4S) BB m (m B +m B ) In (4S) frame Energy-Momentum conservation :, Belle Coll. resolution improvement, background separation

14 Jolanta Brodzicka, INP Kraków B D D sJ decays B D D sJ decays Reconstructed modes: B 0 D - D sJ + B 0 D - D sJ + B+ D 0 D sJ + M( D SJ ) GeV/c 2 E GeV E GeV Events/10MeV Both isospin related modes data sample: 115 fb -1, Belle Coll. Signal extracted in E, M bc and M(D SJ ) Plot one of them with cuts on the others D S decay angle of D S ± decay angle of in D SJ (2457) D S (B D D SJ ) in D SJ (2457) D S ± (B D D SJ ) J=1hypothesisJ=2hypothesis

15 D SJ in exclusive B decays – summary Jolanta Brodzicka, INP Kraków first observation of D SJ states in B decay in Belle first observation of D SJ states in B decay in Belle no new D SJ decay modes in comparison to inclusive production no new D SJ decay modes in comparison to inclusive production masses and widths consistent masses and widths consistent D SJ (2457) angular analysis consistent with J=1 D SJ (2457) angular analysis consistent with J=1 measured BRs do not exclude cs states assignments measured BRs do not exclude cs states assignments, Belle Coll. BR(B DD SJ ) BR(D SJ ) comparison: BR(DD SJ )xBR( D SJ (2457) D S ) BR(DD SJ )xBR( D SJ (2457) D S ± ) BR(DD SJ )xBR( D SJ (2457) D s * 0 ) BR(DD SJ )xBR( D SJ (2457) D s * ± 0 )

16 Jolanta Brodzicka, INP Kraków New D ** 0 states data sample : 60 fb -1 data sample : 60 fb -1 Dalitz analysis for : Dalitz analysis for : B D + + (~1100 signal events) and B D* + + (~600 events) B + D (~1100 signal events) and B + D* (~600 events) unbinned likelihood fit performed with signal density function: unbinned likelihood fit performed with signal density function: S (M 1 2, M 2 2 ) = M 1 2, M 2 2 ) + 2 R(M 2 ) S (M 1 2, M 2 2 ) = A i exp(i i ) BW i ( M 1 2, M 2 2 ) + Aexp(i ) 2 R(M 2 ) both with good S/B expected decay modes: D +, D* + expected decay modes: D - +, D* - +, Belle Coll. coherent sum of the amplitudes of D** states which can contribute and phase space term coherent sum of the amplitudes of D** states which can contribute and phase space term convolution with experimental resolution convolution with experimental resolution

17 Jolanta Brodzicka, INP Kraków D ** 0 mesons Dalitz plot projectionswith fit results First observation of D* 0 and D 1 0 Background M ( D min ) GeV/c 2 M ( D* min ) GeV/c 2 M ( D* min ) GeV/c 2 M ( D* min ) GeV/c 2, Belle Coll.

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

19 Measured masses versus model predictions Jolanta Brodzicka, INP Kraków, Belle Coll. In cu spectrum: masses of D, D*,D** consistent with model expectations In cu spectrum: masses of D, D*,D** consistent with model expectations In cs case: masses of new D SJ (2317) and D SJ (2457) inconsistent In cs case: masses of new D SJ (2317) and D SJ (2457) inconsistent Nowaks talk Nowaks talk Chiral symmetry broken chiral partners split off ( states with opposite parity ) D SJ (2317) and D SJ (2457) interpreted as chiral partners of D S and D* S ? Model expectation: M(cs ) – M(cu) 100 MeV

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

21 X(3872) Jolanta Brodzicka, INP Kraków Events/5MeV Events/15MeV E GeV E GeV Mbc GeV M ( J/ + - ) GeV Signal B ± X(3872)K ± extracted in E, M bc and M( J/ + - ) Signal B ± X(3872)K ± extracted in E, M bc and M( J/ + - ) Plot one of them with cut on the others Plot one of them with cut on the others Simultaneous fit in 3 variables Simultaneous fit in 3 variables M X = ± 0.6(stat) ± 0.5(syst) MeV X < 2.3 MeV ( 90% C.L. ) X < 2.3 MeV ( 90% C.L. ) S = (10 ) M X > M(D + D ) open-charm decay possible, why so narrow ? M X > M(D + D ) open-charm decay possible, why so narrow ? X produced in B decays: J cannot be high X produced in B decays: J cannot be high Is it charmonium state? Is it charmonium state? One of the unobserved higher charmonium states 1 3 D J 1 1 D P P 1 ? One of the unobserved higher charmonium states 1 3 D J 1 1 D P P 1 ? (predicted X mass region) (predicted X mass region) M X M(D 0 + D* 0 ) loosely bounded molecular or hybrid state? M X M(D 0 + D* 0 ) loosely bounded molecular or hybrid state?, Belle Coll.

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

23 Properties of X(3872) Jolanta Brodzicka, INP Kraków 2 3 P 1 ? X( 3872 ) J/ 2 3 P 1 ? X( 3872 ) J/ ( 2 3 P 1 J/ ) ( 2 3 P 1 J/ ) ( 2 3 P 1 J/ + - ) ( 2 3 P 1 J/ + - ) 11keV / 0.3keV 30 11keV / 0.3keV 30 Theory: c1 ( 2 3 P 1 ) ruled out c1 ( 2 3 P 1 ) ruled out M ( J/ ) - M ( J/ ) GeV B ± K ± J/ B ± K ± J/ Absence of X(3872) h c ( 2 1 P 1 ) ? cos (J/ ) X(3872) J/ + - (B K X(3872) ) J/ decay angle in Prediction for 1 + : 1- cos 2 (J/ ) 1- cos 2 (J/ ) h c1 ( 2 1 P 1 ) ruled out, Belle Coll.

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

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

26 Jolanta Brodzicka, INP Kraków, Belle Coll.

27 D mesons D s mesons L=1 L=1 Jolanta Brodzicka, INP Kraków, Belle Coll.

28 Jolanta Brodzicka, INP Kraków, Belle Coll.


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