Charmonium and Charm Spectroscopy at the e e BFactories

1
Charmonium and Charm Spectroscopy at the
ee- B-Factories

• FPCP 2006, Vancouver
• April 10, 2006
• Helmut Marsiske, SLAC

2
Outline
Note Microsoft convention underline ? over
bar

• Charmonium-candidate States
• X(3872), X(3940), Y(3940)
• Y(4260), Z(3930)
• Charmed-strange Mesons
• DsJ(2317), DsJ(2460)
• Charmed Baryons
• ?c(2940), ?cx(2980), ?cx(3077)

Tetraquarks, DD molecules, ccg hybrids, et
c.
No (charmed) Pentaquarks _at_ B-factories
3
Charm/onium Productionat BABAR, Belle, and CLEO

• Continuum production vs
  10.58 GeV
  
• ee-?cc
  (ISR, double charmonium)
  
• two-photon

• Production in B decay vs
  5.28 GeV
  
• b?c transition
• B?(cc)K()

Very large data samples 450-700M cc events,
380-590M BB events
Detectors with excellent tracking, vertexing,
e.m. calorimetry, and particle ID
4
X(3872)???-J/?
Belle 152M BB PRL 91, 262001 (2003)

• Observed in B-decay

Belle 275M BB hep-ex/0505038
BABAR 232M BB PRD 73, 011101 (2006)
N61.215.3 (6.1 s)
N49.18.4
B only
B and B0
Solid hist. mES sidebands
5
Inclusive Search for B?K X(3872)
BABAR 232M BB PRL 96, 052002 (2006)

• BB sample with one B
  fully reconstructed
  
• Two-body decay of other B
  ?
  monochromatic line in
  the kaon momentum
  spectrum in the B-meson
  
  center-of-mass (CM) frame

No charged X(3872) observed
6
X(3872)??J/? ? C(X)1

BABAR 287M BB Preliminary
N19.45.7 (3.4 s)
Belle 275M BB hep-ex/0505037
Bs in 64MeV bins of M(?J/?)
N13.64.4 (4.0 s)
S1.3
7
??- Invariant Mass Spectrumin X(3872)???-J/?
Belle 275M BB hep-ex/0505038

• C(X)1 ? IG(JPC)??- 1(1--) ? ?0
• Expect ??- invariant
  mass spectrum to
  
  peak near the upper
  kinematic boundary
• ??- - J/? in relative
  S-wave or P-wave
  
• M(??-) centrifugal suppression
• S-wave JPC(X) 0, 1, 2
• P-wave JPC(X) 0-, 1-, 2-
• P(X(3872))1 preferred

Shaded X(3872) sidebands
S-wave
P-wave
?2/d.o.f 43.1/39
?2/d.o.f 71.0/39
8
X(3872) Isospin
BABAR 234M BB PRD 71, 031501 (2005)

• Isospin1 for C1 ??-J/? final state,
  but no charged partners X(3872)
  
• ? Initial state X0(3872) isospin0
  ? X(3872)???-J/? isospin-violating
  decay
  
• Isospin-allowed decay X(3872)???- ?0 J/?
  suppressed by kinematics
  
• C(X)1 ? IG(JPC)??- ?0 0-(1--) ? ?

Belle 275M BB hep-ex/0505037
9
B?K X(3872), X(3872)???-J/? Decay Angular
Distributions
Belle 275M BB hep-ex/0505038

• Exclude JPC 0-, 0
  with ?2/d.o.f 34.2/9,
  31.0/9
  
• Consistent with JPC 1
• Inconclusive for JPC 2

Red X(3872) sidebands
Angles in the X(3872) rest frame
J.L. Rosner, PRD 70, 094023 (2004)
10
X(3872)?D0D0?0 (D0D0)
Preliminary
Belle 270M BB MoriondQCD06

M(D0D0?0) in B signal region
?Eshaded ?E sidebands
M(D0D0p0) M(X)
JPC2 ? D-wave required ? very unlikely so
close to threshold
Decay into 3 pseudoscalars excludes JP0
No DD decay for JP1
Everything consistent with I0, JPC1 for
X(3872)
11
X0(3940)
Belle 375 fb-1 hep-ex/0507019

• Observed in the recoil against J/?
  in cc continuum events together
  with three known C1 cc states
  ?c , ?c0 , ?c (2S)

N26663 (5.0 s)
Possible interpretation X(3940) ?c(3S)
DD threshold
JPC0- for ?c(3S)
Surprisingly large J/?-(cc) cross section for
NRQCD
12
X0(3940)?DD
Belle 375 fb-1 hep-ex/0507019

• Above D()D threshold ? search for DD and DD
  decay constrain recoil against (J/? D)

Shaded D sidebands
DD
No DD decay for JPC0-
D- D P-wave for JPC0-
N24.56.9 (5.0 s)
DD
No large decay into ?J/?
13
Y(3940)??J/? ? C(Y)1
Belle 275M BB PRL 94, 182002 (2005)

• Large threshold enhancement
  observed in B-decay
  
• If interpreted as S-wave resonance
• Unlikely decay mode for cc state
  above
  D()D threshold
  
• Different from X(3940)?

Bs in bins of M(?J/?)
N5811 (8 s)
14
Z(3930)?D0D0, DD-
Belle 395 fb-1 PRL 96, 082003 (2006)

• Observed in two-photon interactions ? C1

N6418 (5.3 s)
Solid line J 2, ?2 ?2/d.o.f 1.9/9
Dashed line no signal
Dashed line J 0 ?2/d.o.f 23.4/9
Solid hists. D sidebands
cos? D angle w.r.t. beam axis in ?? CM
Likely 23P2 cc state ?c2(2P)
15
Y(4260)???-J/?
BABAR 233 fb-1 PRL 95, 142001 (2005)

• Observed in ISR events ? JPC 1--
• Indication in B-decay ? needs confirmation

Assuming single resonance
N12323 (8 s)
BABAR 232 fb-1 PRD 73, 012005 (2006)
Peak cross section s(ee-?Y)(5112) pb
BABAR 232M BB PRD 73, 011101 (2006)
16
Confirmation of Y(4260)
in CLEO-c Scan vs3.77 - 4.26 GeV
CLEO-c 13.2 pb-1 hep-ex/0602034

• Enhanced cross section for
  ee-???J/? _at_ vs4.26 GeV

NB BABAR ??-J/? peak cross section (5112) pb
N37 (11 s)
N8 (5.1 s)
No sign of ?(4040)?(3S) decay to ??-J/?
? Y(4260) ?(4S) assignment less likely
17
More Confirmation of Y(4260)from CLEO-III

CLEO-III 13.3 fb-1 Preliminary

• ISR production of ??-J/? events in
  CLEO-III data near vs10.58 GeV

Note CLEO-III efficiency is 1.7 times BABAR.

Boost? Detector??
N12 (4.9 s)
18
No Indication for Y(4260)
in Other ISR-produced Final States
BABAR 232 fb-1 To.b.subm.to PRD

BABAR 289 fb-1 To.b.subm.to PRL
Preliminary
Preliminary
BABAR 232 fb-1 PRD 73, 012005 (2006)
19
Charmonium-candidate States
Tetraquarks, DD molecules, ccg hybrids, etc.
20
Update on Charmed-strange MesonsDsJ(2317) and
DsJ(2460)
BABAR 232 fb-1 Submitted to PRD

• Comprehensive study of decays to
  Ds plus one or two ?, ?0, or ?s
  
• Decay pattern if JP0 and JP1, respectively

Preliminary
Ds?0 only decay mode observed for DsJ(2317)
NB all Seen modes are also Allowed
21
DsJ(2317)?Ds?0
BABAR 232 fb-1 Submitted to PRD
N318080

• No indication of neutral or doubly-charged
  partner near 2317 MeV ? I0

Preliminary
Ds(2112) signal
Preliminary
Ds(2112) reflection
Dark shade DsJ(2460) reflection
Circles Ds sidebands
22
B?D DsJ(2317), DsJ(2317)?Ds?0
Belle 274M BB BELLE-CONF- 0461 (2004)

• DsJ(2317) decay mode ? natural spin-parity
• DsJ(2317) decay angular distribution ? spin 0

Dotted line J 1 ?2/d.o.f 38/8
Natural spin- parity ? JP 0
Solid line J 0 ?2/d.o.f 3/8
23
DsJ(2460)?Ds ? / Ds(2112)?0
Ds?Ds?
DsJ(2460)?Ds ?

Preliminary
Preliminary
N56040
Open points Ds sidebands
Light shade Ds(2112) reflection
Dark shade DsJ(2317) reflection
N92060
Open points Ds sidebands
BABAR 232 fb-1 Submitted to PRD
Preliminary
24
B?D DsJ (2460)
Belle 274M BB BELLE-CONF-0461 (2004)

(b) DsJ(2460)?Ds ?
(c) DsJ(2460)?Ds (2112) ?0
Ds? Ds ?
No Ds ? decay for J0
Ds?0
Dashed line J 2 ?2/d.o.f 89/8
Solid line J 1 S-wave
Solid line J 1 ?2/d.o.f 4/8
JP 1
cos(?Ds?0)
25
DsJ(2460)?Ds??-
BABAR 232 fb-1 Submitted to PRD
N63
Preliminary

• No indication of DsJ(2317)
• Also observe Ds1(2536)

DsJ(2317)
N19322
N12315
Ds1(2536)
DsJ(2460)
Preliminary
Preliminary
26
DsJ(2460) Absolute Branching Fractions (BFs)
BABAR 230M BB To.b.subm.to PRL

• BB sample with one B fully reconstructed
  ? study decays of other B?D(),0 X
  
• Observe DsJ(2460) signals in the recoil mass, mX
  
  

27
DsJ(2460) Absolute BFs, cont.
BABAR 122M BB PRL 93, 181801 (2004)

• Combine with previously measured,
  exclusive product BFs
  B?D() DsJ (2460),
  DsJ(2460)?Ds? / Ds(2112)?0 to
  obtain absolute BFs
• Sum of known BFs 0.700.15

Preliminary
(Ds? Ds ?)
28
Charmed-strange Mesons
cs P-wave, tetraquarks, etc.
DsJ(2460) absolute branching fractions (BFs)
BABAR 232 fb-1 Preliminary
BABAR 230M BB Preliminary
Belle 274M BB BELLE-CONF-0461 (2004)
29
New Charmed Baryon ?c(2940)
BABAR 287 fb-1 Submitted to PRL

• Observed in cc continuum events
  in the decay mode D0p (D0?K-?, K-???-)
  
• First observation of
  
  ?c(2880)?D0p
  
• No structure in Dp
• No doubly-charged
  partner for either state

Preliminary
N2280310 (7 s)
N3020 220
30
Two New Charmed-Strange Baryons ?cx(2980) and
?cx(3077)
Belle 462 fb-1 MoriondQCD06

• Observed in cc continuum events
  in the decay mode ?cK-? (?c?pK-?)
  

Preliminary
No structure in right- sign ?c sidebands or wro
ng-sign ?cK?-,
?cK-?- modes
No indication of doubly-charmed ?cc(3520) (SEL
EX)
31
Summary Charmed Baryons
Belle 462 fb-1 MoriondQCD06
BABAR 287 fb-1 Preliminary

• Three new states
• New decay mode

32
Summary Charmed-strange Mesons

• Consistent with cs P-wave states
• Masses unexpectedly low

Belle 274M BB BELLE-CONF-0461 (2004)
DsJ(2460) absolute branching fractions (BFs)
BABAR 232 fb-1 Preliminary
BABAR 230M BB Preliminary
33
Summary Charmonium-candidate States
34
Backup slides
35
Charmonium-candidate States
Tetraquarks, DD molecules, ccg hybrids, etc.
36
Searches for X(3872)???-J/?
in other processes

• No ISR production
  ? JPC ?
  1--
  
• No quasi-real two-photon production
  ? JPC ? 0-, 0, 2
  

BABAR 89 fb-1 PRD 71, 052001 (2005)
CLEO 15.1 fb-1 PRL 94, 032004 (2005)
37
??- Invariant Mass Spectrumin X(3872)???-J/? ,
cont.
CDF II 360 pb-1 hep-ex/0512074

• C(X)1 ? IG(JPC)??- 1(1--) ? ?0
• ??- - J/? in relative S-wave or P-wave
• S-wave JPC(X) 0, 1, 2
• P-wave JPC(X) 0-, 1-, 2-, 3-

1260130 X(3872) candidates
Unable to distinguish S-wave (P1) and P-wave (
P-1)
38
X0(3872) in B and B0 Decays
BABAR 232M BB PRD 73, 011101 (2006)

• Charge-specific branching fractions
• Mass difference

N8.34.5 (2.5 s)
B0 only
39
X(3872) in B and B0 Decays

• Charge-specific branching fractions

BABAR 232M BB PRD 73, 011101 (2006)
40
X(3872)?J/???-

• Belle discovery
• Unexpected discovery mode
  for charmonium
  state
  above open-charm threshold
• BABAR search for X(3872)?J/???-
  in Initial
  State Radiation (ISR) Events
  
• ISR ? ee- collisions with a
  continuum of center-of-mass
  
  (CM) energies below the ?(4S)
• Search
  final state

PRL 91, 262001 (2003)
41
No evidence for Y(4260) in R-scan

• Dip in R at
  vs4.26GeV
  
• R3 and
  
  
• s(14.20.6)nb

Y(4260) decay mode ? conventional charmonium i
nterpretation does not fit well
Factors 10 and 20 larger than J/???- partial
width
of ?(2S) and ?(3770), resp.
42
Indication of Y(4260) ?J/???- in B decay

• Search for
• 3.1s significance, assuming mass and width
  from ISR analysis needs
  confirmation

PRD 73, 011101 (2006)
232M BB
43
??- Invariant Mass Spectrum in Y(4260)???-J/?

• C(Y) -1 ? IG(JPC)??- 0(0, 2)

BABAR 233 fb-1 PRL 95, 142001 (2005)
CLEO-c 13.2 pb-1 hep-ex/0602034 Submitted to PR
L
Solid hist ??- phase space for (??-) - J/?
S-wave
Solid hist ??- spectrum like in ?(2S)? ??-J/?
Ys in bins of M(??-)
??- invariant mass spectrum inconclusive
44
Other Y(4260) Decay Modes?
BABAR 232 fb-1 PRD 73, 012005 (2006)
45
Discovery of X(3872)?J/???-

• Belle
• Confirmed by CDF, D0, and BABAR
• X(3872) properties
• Mass at DD threshold
• Narrow width
• JPC1 favored
• m(??-) consistent with ?
• No evidence for charged partner X(3872)

PRL 91, 262001 (2003)
157M BB
46
X(3872)
47
X(3872)

• Some DD molecule predictions

48
Charmed-strange Mesons
BABAR 91 fb-1 PRL 90, 242001 (2003)
CLEO 13.5 fb-1 PRD 68, 032002 (2003)
Belle 124M BB PRL 91, 262002 (2003)

• DsJ(2317) and DsJ(2460) first observed by BABAR
  and CLEO in cc continuum
  events, and by
  Belle in B-decay
• Both masses unexpectedly low below DK and DK
  threshold, respectively
  
• Only isospin-violating or electromagnetic decays
  kinematically allowed ?
  narrow widths
  
• Decay pattern and decay angular distributions
  consistent with interpretation as P-wave cs
  mesons with JP0 and JP1, respectively

49
Charmed-strange Mesons
50
Summary of DsJ(2317) and DsJ(2460) Branching
Ratio Results
BABAR 232 fb-1 Submitted to PRD
51
DsJ(2460) Absolute Branching Fractions (BFs)
BABAR 230M BB To.b.subm.to PRL
52
Charmonium System

• Below DD threshold
• Large
• PDG
• Above DD threshold
• Small
• CLEO
• Surprise
• Mass, width, and decay mode ? conventional
  charmonium interpretation does not fit well

53
(No Transcript)
54
(No Transcript)
55
Charmed Baryons

• All nine JP1/2 ground states (L0, Jqq0,1)
  observed
  
• All but one of six JP3/2 ground states (L0,
  Jqq1) observed
  
• Growing number of excited
  states (L1)
  
• No confirmed doubly- charmed
  baryons yet

56
Summary

• Charmonium-candidate States
• X(3872) I0, JPC1
• X(3940) ?c(3S), JPC0- ?
• Y(3940) I0, C1
• Z(3930) ?c2(2P), JPC2
• Y(4260) I0, JPC1- -
• Charmed-strange Mesons (cs P-wave states)
• DsJ(2317) I0, JP0
• DsJ(2460) JP1
• Charmed Baryons
• ?c(2940)?D0p
• ?cx(2980), ?cx(3077)? ?cK-?

? New Charmed Baryon States
57
CLEO-c scan (Preliminary)
58
Workplace