Meson Spectroscopy at B factories 8 GeV e GeV e + BaBar Belle

Talk Outline X(3872) Y(4260) X(3940) Y(3940) Y(4325) D sJ (2317) D sJ (2460) Stephen Olsen U. of Hawai’I & 高能所 北京 PPP7 NTU, Taipei June 7-11,2007

B-factories are Charm & Charmonium factories c & cc meson production mechanisms B meson decays e + e - annihilation  collisions e + e - radiative return (isr)

D & D s production in B decays More than 1 charmed particle/B meson u q d D,D*,.. ,.. s c q D,D*, D s,D s *,..

cc production in B decays j=½ J = 0 or 1 Spectator model says J cc = 0 or 1 should dominate exclusive B  K(cc) decays.

Allowed decays all have Bf~10 -3 from PDG2004  c K 0.9 x10 -3 J  K 1.0 x10 -3 J/  K* 1.4 x10 -3  ’ K 0.7 x10 -3  ’ K* 0.9 x10 -3  c0 K 0.6 x10 -3  c1 K 0.7 x10 -3 J/  K x10 -3 B  K cc(J=2) still not seen

  DD J PC = 0 ++, 2 ++ e + e -  cc (continuum) c c  (e + e -  cc)>  (  (4S))

Radiative return J PC = 1 -- c e + e -   DD e + e -   (cc) D,D*,..

e + e -  J/  + (cc) J/  X X (almost) always contains (cc) C(X) = +1 consistent with bkg c c  c0 c’c’ M(X)

All of these processes have produced discoveries/surprises B decays:  c ’, X(3872), Y(3940) e + e -  cc continuum: D**’s,D sJ (2317),…   DD: Z(3940) Radiative return: Y(4260), Y(4320) e + e -  J/  cc: X(3940)

These results have received considerable interest

SPIRES: find cn BaBar and topcite=250+ 1) Observation of a narrow meson decaying to D+(s) pi0 at a mass of 2.32-GeV/c**2. By BABAR Collaboration (B. Aubert et al.).. Published in Phys.Rev.Lett.90:242001,2003. B. Aubert et al. Cited 393 times393 times 2) Observation of CP violation in the B0 meson system. By BABAR Collaboration (B. Aubert et al.). SLAC-PUB-8904, BABAR-PUB-01-18, Jul Published in Phys.Rev.Lett.87:091801,2001. B. Aubert et al. Cited 385 times385 times 3) Measurement of the CP violating asymmetry amplitude sin 2beta. By BABAR Collaboration (B. Aubert et al.).. Published in Phys.Rev.Lett.89:201802,2002. B. Aubert et al. Cited 364 times364 times D sJ =most cited BaBar result

SPIRES: find cn Belle and topcite=250+ 1) Observation of large CP violation in the neutral B meson system. By Belle Collaboration (K. Abe et al.). Published in Phys.Rev.Lett.87:091802,2001. Cited 398 timesK. Abe et al.398 times 2) Observation of a narrow charmonium - like state in exclusive B+- ---> K+- pi+ pi- J / psi decays. By Belle Collaboration (S.K. Choi et al.). Sep pp. Published in Phys.Rev.Lett.91:262001,2003S.K. Choi et al. Cited 279 times279 times 3) A Measurement of the branching fraction for the inclusive B ---> X(s) gamma decays with BELLE. By Belle Collaboration (K. Abe et al.). Published in Phys.Lett.B511: ,2001K. Abe et al. Cited 278 times278 times 4) An Improved measurement of mixing induced CP violation in the neutral B meson system. By Belle Collaboration (K. Abe et al.). Published in Phys.Rev.D66:071102,2002.K. Abe et al. Cited 252 times times X(3872) J = 2 nd most cited Belle paper

The D** mesons B + →D* - π + π + B + →D - π + π + Belle: 65 M BB PRD 69, (2004) Spectroscopy and allowed transitions of D mesons

The D sJ mesons D sJ (2317) → D s π 0 D sJ (2460) → D s *π 0 BABAR: 91 fb-1 PRL 90, (2003 CLEO: 13.5 fb-1 PRD 68, (2003 BaBar: 240 fb-1 PRL 97, (2006) Belle: 449 M BB hep-ex/ D sJ (2860) → DK

The D**/D sJ meson puzzle (two slides only) ~145 MeV ~0 MeV BaBar CLEO Belle

Replace a u/d quark with an s quark u c s c + ~145 MeV ≈(m s -m u ) S-Wave P-Wave u c s c No penalty

Charmonium is of particular interest because it is a good system to use to search for non-qq mesons

a cc meson has to fit into these slots:

“XYZ” particles X(3872) –     J/  in B  K     J/  Z(3930) –DD in   DD Y(3940) –  J/  in B  K  J/  X(3940) – e + e -  J/  X & e + e -  J/  DD* Y(4260) –     J/  in e + e -      J/  Y(4320) –  +  -  ’ in e + e -   +  -  ’ Are these charmonium states?

  Z(3931)  DD at Belle 41  11 evts (5.5  ) M=3931  4  2 MeV  20  8  3 MeV sin 4  (J=2) Matches well to  c2 ’ expectations M(DD) GeV Uehara (Belle) PRL 96, (2006)

Z(3930): candidate for the  c2 ’ 3931 M= 3931 MeV is ~45 MeV low  =20MeV too narrow? Masses from Barnes, Godfrey & Swanson PRD 72, (2005)

e + e -  J/  X(3940) e + e -  J/  + X Pakhlov (Belle) PRL 98, (2007)

X(3940)  D*D is strong (  DD &   J/  not seen) D B(D*D)>45% consistent with  100% B(DD)<41% From X(3940) → D * D: M = (3943 ± 6 ± 6) MeV  = (15.4  10.1) MeV  < 52 MeV at 90%CL Pakhlov (Belle) PRL 98, (2007) Higher statistics Belle results this Summer

Is the X(3940) the  c ”? 3940 M= 3943 MeV is ~150 MeV low  <52MeV too narrow?

X(3872) in B  K     J/  M(  J  )  ’      J/  X(3872)      J/  PRL 91,   2.9 MeV

Also seen in pp X(3872) CDF hep-ex/  Production properties similar to those of the  ’ X(3872) D0 PRL 93, (2004) PRL 93, (2004)

C=+1 is pretty well established X(3872)   J/  seen in: & PRL M(  looks like a  X(3872)  ”  ”J/  seen CDF Belle hep-ex/ Belle Swanson PL B588, 189(2004)

ll |cos  l  |  2 /dof = 34/9  |cos  | |cos  |  2 /dof=34/ rule out 0 ++ & 0 -+     J  k    x  J   Ruled out by Belle

Angular analysis from CDF CDF PRL (2007) 1 ++ or 2 -+

X(3872) has no satisfactory cc assignment 3872  r  J/  too small &  r (  J/  ) too big  c1 ’  c    J/  ispin forbidden D 0 D 0  thresh. suppressed B  Kcc(J=2) suppressed  c2

Mass is near the D 0 D* 0 threshold PDG06: m D0 + m D*0 = ± 0.8 MeV PDG M X3872 : ± 0.5 MeV D* 0 D 0 ”binding energy” = 0.4 ± 0.6 MeV CLEO hep-ex/ ± 0.4 MeV My average: ± 0.4 MeV

hh bound states (hadronium) ?? pn DD* deuteron: loosely bound 3-q color singlets with M d = m p +m n -  Hadronium (dueson) : loosely bound q-q color singlets with M = m D + m D* -  attractive nuclear force attractive force??   N.. A. Tornqvist, Phys Lett. B 590, 209(2004) F. Close, P.R. Page, Phys. Lett. B 578, 119 (2003) E.S. Swanson, Phys. Lett, B (2004) E. Braaten, M. Kusunoki, S. Nussinov, Phy. Rev. Lett. 93, (2004) M. Voloshin & L. Okun, JETP Lett. 23, 333 (1976) A. DeRujula H.Georgi & S.Glashow, PRL 38, 317 (1977)

Belle: Threshold peak in B  KD 0 D 0  0 M=  0.7  0.8 MeV Br(X  D 0 D 0  0 ) Br(X      J/  ) ~ M(DD  ) EE Gokhroo (Belle) PRL (2006) ~2  higher than in the  J/ y mode

BaBar confirms the B  (D 0 D *0 ) K threshold enhancement BaBar, Moriond 2007 The is also 2.5σ high

Molecular models have trouble with a large DD  decay rate

X(3872) = D 0 D* 0 bound state? J PC = 1 ++ is favored M ≈ m D0 + m D0* Large isospin violation is natural ( & was predicted) :  |D 0 D* 0 > = 1/  2 (|10> - |00>)  (X   J/  ) <  (X   J/  ) was predicted  (X  D 0 D 0  0 ) too large? X  DD  peak mass > m D0 + m D0* Equal mixture of I=1 & I =0 Swanson PLB 598, 197 (2004) Tornqvist PLB 590, 209 (2004) Swanson PLB 588, 189 (2004)

Real or virtual DD* state? hep-ph/  J/  DDDD DDDD

diquark-antidiquark? uc u c dc d c Xu=Xu= Xd=Xd= B+K+XuB+K+Xu B0K0XdB0K0Xd BaBar Maiani et al predict:  M = M(X u ) – M(X d ) = 8  3 MeV BaBar PRD R (2006):  M = 2.7  1.3  0.2 MeV L. Maiani, F. Piccinini, A. D. Polosa, V. Riquer PRD71: (2005) Predict a doublet of states:

Y(3940) in B  K  J/  M≈3940 ± 11 MeV  ≈ 92 ± 24 MeV Belle PRL94, (2005) M(  J/  ) MeV  (Y 3940   J/  > 7 MeV (an SU F (3) violating decay) ~ this is 10 3 x  (  ’   J/  (another SU F (3) violating decay) if the Z(3930) is the  c2 ’ the Y(3940) mass is too high for it to be the  c1 ’

Is there a cc slot for Y(3940) ? Can M(  c1 ’)>M(  c2 ’)?  c1 ’ Mass is low c”c” “ “  c0 ’

e + e -   isr Y(4260) at BaBar 233 fb -1  e  e    +   J/    pb  (Y4260      J/  ) > 90% CL Y(4260) X.H. Mo et al, PL B640, 182 (2006) 4260 BaBar PRL95, (2005) Not seen in e + e -  hadrons BES data ~3nb ~50pb

Y(4260) at Belle M=4295  MeV  = 133  MeV For  ’      J/  in the same data: M(  ’) =  0.1 MeV (PDG: M(  ’)=  0.04) Belle hep-ex/

Y(4260) at CLEO-III Consistent results 13.3 fb -1 ISR  (1S)-  (4S) 13.3 fb -1 CLEO PRD (2006) M =  4 MeV  =  5 MeV

No 1 -- cc slot for the Y(4260) X.H. Mo et al, hep-ex/

Is the Y(4260) a cc-gluon hybrid? cc qq-gluon excitations predicted in lowest 1 -- cc-gluon mass expected at ~4.3 GeV relevant open charm threshold is D**D (~4.28 GeV)  (  J/  ) larger than that for normal charmonium  (e + e - ) smaller than that for ordinary charmonium Horn & Mandula PRD 17, 898 (1977) Banner et al, PRD 56, 7039 (1997); Mei & Luo, IJMPA 18, (2003) Isgur, Koloski & Paton PRL 54, 869 (1985) McNeile, Michael & Pennanen PRD 65, (2002) Close & Page NP B443, 233 (1995) Y(4260)seems to fit all of the above!!!

DD** threshold in relation to the “Y(4260)” 4.28-m D D** spectrum M(     J/  ) GeV No obvious distortions D1DD1D D2DD2D

A      ’ enhancement at 4325MeV Incompatible with  (4415), nor well described by Y(4260) A single resonance can describe the structure (<5.7 GeV/c 2 ) well  mass=(4324  24) MeV/c 2,  =(172  33) MeV ( statistical errors only ) Nbkg = 3.1  1.0 Nevt = 68 (<5.7 GeV/c 2 )  2 -prob < 5.7 GeV/c 2 Y(4260) 6.5   (4415)1.2  Y(4320)29% e + e -   ISR      ’ M=4324  24 MeV  = 172  33 MeV above all D**D thresholds S.W.Ye QWG-2006 June 2006 Not Compatible with the Y(4260) D1DD1D D2DD2D 298 fb -1 (BaBar) hep-ex/

BaBar hep-ex/  (e + e -  DD) Y(4325)

 (e + e -  D*D ( * )  s  4 GeV Belle: ISR + Partial Reconstruction Pakhlova (Belle) PRL 98, (2007)  (e + e -  D* + D* - )  (e + e -  D + D* - )  (4040)  (4160)  (4415) Y (4260) Y (4325)

D*D* DD* DD  tot The parameters of the above-threshold 1 – charmonium states determined from fits to  tot with incoherent BW’s are probably not very reliable

summary (XYZ) Z(3931) (   DD) –Probably the  c2 ’ X(3940) (e + e -  J/  X) –C=+1 –Could be the  c ” (albeit with some stretching) X(3872): –J PC = 1 ++ –Br(X      J/  ) large –Br(X  D 0 D 0  0 ) seen; ~ 9xBr(X      J/y) D*D

Summary (XYZ) cont’d Y(3940)   J/  –  ( Y 3940   J/  ) >7 MeV (huge!) “Y(4260)”   +  - J/  –  (y 4260      J/  )>1.6 MeV – J PC =1 --, not seen in e + e -  hadrons -no obvious D**D threshold distortions “Y(4325)”   +  -  ’ – above all  D**D thresholds 233 fb -1

conclusions There seems to be a new hadron spectroscopy in the 3.5~4.5 GeV mass region –Maybe more than one –Bodes well for BESIII, Super B factories & PANDA The new states are characterized by large partial widths (Bfs) to hadrons+J/   – Br(X(3872)   J/  ) > 4.3% (Isospin=1) –  (Y(3940)   J/  ) > 7 MeV (SU(3) octet) –  (Y(4260)      J/  ) > 1.6 MeV There is no apparent transition at the D**D mass threshold The above-threshold 1 -- charmonium state parameters listed in the PDG are probably not reliable (mine)

Expect lots of results from Belle this summer

謝謝

Look at e + e -  J/  D(D ( * ) ) Reconstruct a J/  & a D use D 0  K -  + & D +  K -  +  + Determine recoil mass

Inclusive B  Kx from BaBar ? Fully reconstructed B - tags

Braaten et al: X  D D *0 mass spectrum Theoretical prediction for a loosely bound D D * state.

BaBar looked for a charged partner of the X(3872) and excluded isospin 1: BF(B 0  X - K + ) BF(X  J/ψ  -  0 ) < 5.4 x BF(B -  X - K 0 ) BF(X  J/ψ  -  0 ) < 2.2 x c.f BF(B 0  X 0 K+ ) BF(X 0  J/ψ  --  + ) =(1.28  0.41 ) x 10 -5

Comments on the D 0 D 0  0 mass peak Fitted M:  0.7  0.8 MeV M–(m D0 + m D*0 ) =  0.7 MeV xPDG06 error on m D0 (could be  2.0 MeV) PDG M X3872 :  0.5 MeV Here error on m D0 drops out Nominally ~2.3   above D 0 D* 0 threshold (but errors are non-Gaussian)  ~2  discrepancy DD* “Binding Energy?”:

Y(4260) at Belle MXMX Select e+e-      ℓ + ℓ - +X; N chg =4 M ℓ + ℓ - =M J/   30MeV; p J/y >2 GeV; M  >0.4GeV | data  4.2<M  J/  <4.4 MC M=4295  MeV  = 133  MeV For  ’      J/  in the same data: M(  ’) =  0.1 MeV (PDG: M(  ’)=  0.04)

M 

Another one from BaBar?  (4352)       ’ (produced via radiative return)