Heavy Quarkonia cc, bb

1
Heavy Quarkoniacc, bb

• Tomasz Skwarnicki
• Syracuse University

2
Long and Short-lived Quarkonia
Laboratory of strong interactions
Factory of weakly decaying heavy flavors
Strong int. physics
G(3S) 24 keV
G(4S) 24 000 keV
W
g
p
p
e
e
Strong interactions impact many
measurements Need to understand
them. New physics can be strongly coupled.
B
b
b
Soft g
g
g
Other states
(1S,2S,3S)
(4S)
B
b
Hard g
b
e-
e-
Short distance interactions
Long distance interactions
Old Physics but still not completely understood
Strong interactions
Weak interactions
New Physics ?
3
Onia
Toponium is not a lab for QCD

• Consequences of large mQ
• velocities of constituents are small
  v
  
• strong coupling constant in annihilation and
  production is small as
• This opens avenues for effective theories of
  strong interactions
• purely phenomenological potential models
• more recently NRQCD and much improved QCD on
  Lattice

Expansion parameters
4
Predicted States
S 0 1 0 1 0 1
L 0 1 2

5
Hadro-production

• Annihilation of n3S1-- (y,) to mm- (ee-) makes
  it possible for experimentalists to fish heavy
  quarkonia states out. This is how they were
  (co)discovered!
• Access to 13P2,1 (c) by adding a photon
• So far not a player in spectroscopy (except for
  the discovery) or decay studies
• Physics in production mechanism
• Used also as a probe for a structure of the
  target (e.g. gluon content)

1.8 TeV p p
200 GeV d Au
J/y(1S)
800 GeV p Cu(fixed)
(1S)
J/y(1S)
CDF
y(2S)
(1S)
(2,3S)
Phenix
(2S)
(3S)
E866
M(mm-) GeV
6
Hadro-production

• NRQCD (leading order)

Cross-section
Beneke,Kramer PRD 55, 5269 (1997), CDF data
Old news color-octet contributions are
important potential problem with
polarization data
NRQCD
Polarization
Braaten, Kniehl, Lee PRD 62, 094005 (2000)
new
CDF Run-II data http//www-cdf.fnal.gov/physics
/new/bottom/030327.blessed-jpsixsec/xsec_html/
7
Photo- and Electro-production

• Large range of kinematical regimes and
  differential cross sections to inspect at HERA

Large number of contributed papers by H1 and ZEUS!
H1
J/y(1S)
ZEUS
y(2S)

• Difficult to reconcile all data with consistent
  theoretical approach (charm not heavy enough ?)

For a more complete review see e.g. Arnd Meyer at
QWG Workshop CERN Nov.02 http//alephwww.physik.u
ni-siegen.de/quarkonium/WS-nov02/WStalks/meyer.pd
f
8
Clean production environments

• Most of what we know about quarkonia states
  and their decays comes from experiments at clean
  production environments, which are reversals of
  simple decay modes

e
e

• Large production rates
• Can study even small BR
• Small backgrounds - inclusive and exclusive decay
  modes
• Works only for vector states.
• Dedicated runs needed (one state at a time).
• Get them for free at ee- machines
• Production rates are small
• Backgrounds - exclusive decay modes with large BR
  only
• So far only charmonium states
• All states can be formed
• Rates can be high
• Large backgrounds can be defeated by constrained
  kinematics -exclusive decays only.
• Works for charmonium states only
• Dedicated runs needed (one state at a time)

Q
Q
g
g
n3S1 ,(n3D1)
JPC 1- -
e-
e-
e
e
g
Q
g
Q
JPC 0- 0 2
n1S0 ,n3P0,2
g
g
e-
e-
p
p
Q
g
Q
g
any JPC
( )
( )
n1P1
g
g
9
pp Annihilation Results

• E835 experiment at FNAL (1996-97, 2000)
• non-magnetic detector (g and e detector)
• Extremely precise determinations of cc(13P2,1,0)
  masses and widths

Example
PL B533, 237 (2002)
Submitted to PRL
They are also analyzing 1M y(2S) decays
10
Singlet States at pp Annihilation
E835

• Recent measurement of hc(11S0) mass by E835 PL
  B566, 45 (2003)
• Non-observation of hc(21S0) by E760 and E835
  PRD62, 052002 (2000)
• Saga of hc(11P1)
• Inconclusive evidence from R704 at ISR (1984)
• Better evidence claimed by E760 (1989-91) in pp?
  hc ?p0J/y, J/y ?ee-.
  Mass close to the center-of-gravity of the
  triplet P-states (as expected if there are no
  long range spin-spin interactions)
• More statistics taken by E835 (also a better
  detector)
• Rumors of disappearance recently in print
  CERN Cour.43N317-18,2003 and other
  preprints (non-E835 authors)
• Official statement from the collaboration
• Looking at all available channels
• Not ready to report any results yet

hc
Ecm (MeV)
E760
hc?
11
Mass of hc(1S)

• Five new measurements

BES-II 58M J/y Phys.Lett. B555, 174 (2003)
2979.91.0 MeV
weight
hc
CL0.5 scale factor1.5 Consistency problem
12
Width of hc(1S)

• Four new measurements

25.03.3 MeV
BaBar 88 fb-1 Preliminary
PDG 16.13.1 MeV
e e ? e e hc
e e ? J/y g
CL0.05 scale factor1.8 Serious consistency
problem!
Gtot(hc) (33.3 2.5 0.8) MeV
29.12.5 MeV CL15 Excluding R704 and C.BALL
13
Rediscovery of hc(21S0)

• B-meson gateway to charmonium states

• All states can be formed
• Backgrounds can be suppressed by B meson mass
  constraint. Additional constraint at ee-
  EBEbeam.
• Get them for free when doing B physics
• Rates can be very low
• Exclusive final states

c
c
b
s
B
K()
W
B? K(KsKp-)
3654 6 8 MeV
14
Double charm production at Belle
2002 results
10 times larger than expected
Belle 102 fb-1 Updated this year
3630 8 MeV 1.9s different
1 pb
0.06 pb
0.06 pb
Preliminary

• Much debated theoretical puzzle!

15
Confirmation of hc(21S0) in gg-collisions
3637.74.4 MeV
hc(2S)
gg? KsKp-
gg? KsKp-
ee-? J/y X
B? K(KsKp-)
hc(2S)
y(2S) ?gX
hc(1S)
hc(2S)
CL14 scale factor1.3 New measurements of mass
are consistent
Gtot(hc(2S)) (1910) MeV
16
Predictions for hyperfine splitting ratio

• For 20 years theorists were exposed to the
  experimental value of DM2SM(y(2S))-M(hc(2S))
  which was wrong by a factor of 2
• Predictions for DM2S/DM1S

Old exp. value
New exp. value
Number of potential models/0.05
Lattice QCD M.Okamoto et al (CP-PACS) PRD65,
094508(2002)
pNRQCD S.Recksiegel,Y.Sumino hep-ph/0305178
Modern potential model TA Lahde, NP,A714,183(2003)

S. N. Jena PL B123, 445 (1983).
H. Ito, Prog. of Theor. Phys. 84, 94 (1990)
DM2S/DM1S
17
First CLEO-c Results
Preliminary
Number of resonance decays (106)
cc(1P1)
cc(1P2)
(1S)
cc(1P0)
2.7 pb-1 1.5M y(2S)
CLEO-c 2003 90 CL U.L. limit on BR(y(2S)
?ghc(2S))
hc(2S)?
(2S)
(3S)
C.Ball 82
y(2S)

• C.Ball82 signal directly ruled out

CLEO-c is the first experiment since the Crystal
Ball which is able to look at inclusive photons
from y(2S)
18
E1 and M1 transitions from y(2S)
BR(y(2S) ?g cc(1PJ)) in
Preliminary
BR(y(2S) ?g hc(1S)) in
Eg in MeV

• Good agreement on branching ratios
• Hindered M1 transition confirmed!
• E1 photons will fix absolute energy scale for
  cb(1PJ,2PJ) mass measurements

y(2S) ?g hc(1S) 8.2s significant
Bkg. subtracted
hc(1S)
19
Photon Spectroscopy in CLEO
E1
M1
7
8
y(2S)
?(3S)
9
J2 1 0
16,17 18
C
8
10
7
9
1
11
2
12 11,10
g g
3
12
16,17 18
13,14,15
6
C
1
2
6 5,4
5,4
A
3
g g g
J2 1 0
B
15 14,13
B
4
ee- mm-
5
g g
6

• M1 no hindered transitions detected in ? decays
  ( no observations of hb(1S,2S) )
• E1
• rare ?(33S1) ? g cb(13PJ) transitions observed
  with good statistics
• Suppressed cb(2,13P0) ? g ? (23S1, 13S1) also
  observed
• precision measurements in progress

?(2S)
2
1
3
A
g g g
6 5,4
g g
A
ee- mm-
Eg ? M(n3PJ) BRg Gtot ? GE1
20
E1,M1 rates vs predictions
M1 matrix elements
E1 matrix elements (GeV-1)
13S1 ? 11S0
McClary 83
Grotch 84
23S1 ? 13PJ
23S1 ? 11S0
23S1 ? 11S0
bb
bb
23S1 ? 13PJ
33S1 ? 23PJ
33S1 ? 21S0
33S1 ? 11S0
33S1 ? 13PJ
allowed range
time
Ebert 03
Lahde 03
S.Godfrey

• Only recent calculations of M1 rates consistent
  with all the data
• Relativistic corrections needed (triangles) to
  describe E1 rates in charmonium. Corrections
  small in bottomonium.
• Small matrix element 33S1 ? 13PJ difficult to
  predict (cancellations)

33S1 ? 13PJ
33S1 ? 23PJ
21
cb(1P) ? w(1S) observed by CLEO
g
w
w
M(pp-p0) GeV
ee-,mm-
Eg MeV
BR(cb(1P2) ? w(1S)) (1.10.30.1)
BR(cb(1P1) ? w(1S)) (1.60.30.2)

• First observed hadronic transistion in heavy
  quarkonia, which is not between triplet-S states.
  First new transition in about 20 years.
• E1E1E1 type. No spin dependence (Voloshin)
  consistent with the data
• No theoretical predictions for the rate of this
  transition

cb(23P0)
22
New state observed by Belle
hadronic event R2 lt 0.4 cosqB lt 0.8

• B ? K(J/y pp-)

? ee- or mm-
14444244443 Mb.c.
Preliminary
M(ll-) - MJ/y lt20 MeV
DM
23
Signal is clearly from B decays

• Fit beam-constrained mass (Mb.c.) in bins of the
  mass of the produced system (MJ/y DM)

B
B
Belle B ? K(J/y pp-)
24
Properties of the state
New State
y(2S)
Control sample for mass scale and resolution
Number of B ? K(J/y pp-) events / 5 MeV

• 34.46.5 events, statistical significance 8.6s
• Mass 3871.80.70.4 MeV
• Observed width consistent with the detector
  resolution.
• Natural width lt 3.5 MeV at 90 C.L.

Belle B ? K(J/y pp-)
Preliminary
25
Possible interpretations

• The mass of the state is right at the D0D0
  threshold!
• This suggests a loosely bound D0D0 molecule,
  right below the dissociation energy
• Molecular Charmonium discussed in literature
  since 1975
• Triggered by complicated structure of s(ee-
  ?hadrons) observed at SPEAR
• M. Bander, G.L. Shaw, P. Thomas, PRL 36, 695
  (1976)
• M.B. Voloshin, L.B. Okun JETP Lett. 23, (1976),
  Pisma Zh.Eksp.Teor.Fiz.23, 369 (1976)
• A.De Rujula, H.Georgi, S.L.Glashow, PRL 38 (1977)
• Interactions described by pion-exchange give
  attractive force for DD, BB
• N.A. Tornqvist, PRL 67, 556 (1991), Z.Phys. C61,
  525(1994)
• A.V. Manohar, M.B. Wise,Nucl.Phys. B339, 17(1993)
  

Diquark Model (Qq) are colored
D0D0 molecule
q
A different idea from that time
Q
Q
Stronger binding
Loose binding
e.g. C.Rosenzweig PRL 36,697 (76)
Decays to (QQ)(light mesons) via
quark rearrangement which suppresses the width.
26
Possible interpretations

• A y(13D2) state
• Because D-states have negative parity, spin-2
  states cannot decay to DD
• They are narrow as long as below the DD
  threshold
• h2(11D2) preferentially decays to hc(11P1).
  Decays to pp- J/y would be of magnetic type and
  are suppressed.
• Some models predict large widths for y(13D2) ?
  pp- J/y
• All models predict even larger widths for y(13D2)
  ? g cc (13P2,1) Should easily see
  y(13D2) ? gg J/y.
• Discovery of the signal is very recent. Belle is
  working on this channel but is not ready to
  present any results.

y(13D3)
y(13D2)
h2(11D2)
y(13D1)
14
g
g
65
g
g
g
7
32
pp-
g
20
Based on E.J.Eichten, K.Lane C.Quigg PRL
89,162002(2002)
J/y
27
CLEO has observed (13D2)
Recoil mass

• Preliminary results presented at ICHEP02
• Update more data and better background
  suppression

g
g
g
g
M((13D2)) 10161.10.61.6 MeV
Scaling to cc using M(2S)-M(1S) M(y(13D2))3831
MeV Scaling to cc using M(1P)-M(1S) M(y(13D2))37
80 MeV vs MX 3872 MeV
GodfreyRosner PRD64,097501(2001)
3.8 10-5
B((3S) ?gg(1D) ? gggg (1S) ? ggggll-) .
(2.60.50.5) 10-5
BR((3S) ? gg(1DJ)) x BR((1DJ) ? h(1S)) lt 2.3
10-4
28
(3S) ? gg pp- (1S), (1S) ? ll-
Search for (13D2) ? pp-(1S)
BR((3S) ? gg(2S)) x BR((2S) ? pp-(1S))
(0.95 0.05)10-2 (statistical error only)
CLEO data
Control signal
Ratio to PDG based value 1.200.18
No signal is observed. At 90 C.L.
gg(1D2)pp-
gg(2S)pp-
BR((3S) ? gg(1D2)) x BR((1D2) ? pp-(1S)) lt
1.1 10-4
?
BR((3S) ? gg(1DJ)) x BR((1DJ) ? pp-(1S)) lt
2.7 10-4 for M(1DJ) in 10140-10180
Voloshin et al approach 6447448
The (1D2) results confirm that photon
transitions are the dominant decays of
D-state heavy quarkonia below the open flavor
threshold
144424443
With Rosners production rates
29
Potential Models Mass Predictions

• What do potential models say about mass of
  y(13D2), (13D2) ?
• Plot predictions for 13D2 states, and for the
  observed states above flavor threshold, y(3770),
  (4S) ,vs. quality of a model (RMS of DM
  Mtheory-Mdata for states below the flavor
  threshold)

X(3872)
measured mass
30 MeV correction needed to the (4S) mass
My(1D1) or My(1D2) MeV
DM(1D2) or DM(4S1) MeV
y(3770)
bb
cc
6 cog masses in the test
3 cog masses in the test
s(DMbb) MeV
s(DMcc) MeV

• All models expect for Fulcher, PRD44,2079(91),
  predict y(13D2) mass to be 70 MeV lower than the
  measured X(3872) mass. At the same time good
  quality models reproduce (13D2) mass very well.
• Coupled channel effects would push the Fulchers
  predictions down gt30 MeV.
• None of the models can accommodate y(3770) and
  X(3872) in the same 13DJ triplet! Can coupled
  channel effects and y(13D1)-y(23S1) mixing change
  this?

30
Relation of y(13D2) ? pp- J/y to y(3770) ? pp-
J/y
These are E1E1 transitions. No spin dependence.
Width for y(13D2) ? pp- J/y should differ from
y(13D2) ? pp- J/y mostly by the phase space
factor.
Observed states.
y(3770)
Mixing q -120 (?)
y(2S)
pp ?
pp
Mixing induced y(3770) ? pp- J/y(1S) is
predicted to be small BR0.04
Kuang,Yan
Yan, Kuang et al predict BR 0.1-0.5 In
Voloshin et al approach the rate would be at
least a factor of 10 smaller
J/y
31
y(3770) ? pp- J/y at BES II

• Data sample 8.00.5 pb-1 (20 scan),
  (5.71.3)104 y(3770) decays
• Efficiency 17.1
• Claim 9 events including 2.20.4 background
  events

ee- ? g y(2S), y(2S) ? pp- J/y
y(3770) ? pp- J/y
BR(y(3770)?pp-J/y(1S)) (0.590.260.16)
LARGE!
pp-ll- events
E(pp-) GeV
4C fit (EEcm,P0)
data
ee- ? g y(2S), y(2S) ? pp- J/y MC
y(3770) ? pp- J/y
E(pp-) GeV
M(ll-) GeV
32
y(3770) ? pp- J/y at CLEO-c
calibration modes
9.1M (2S)
e 26

• Data sample 5.20.2 pb-1, (4.50.4)104 y(3770)
  decays
• Efficiency 37.1
• lt 4.75 events at 90 C.L.

1300.0 pb-1
B1.5T
21,300 events
(2S) ? pp- (1S)
BR(y(3770)?pp-J/y(1S)) lt0.26 at 90
C.L.
1.5M y(2S)
e 37
1.0T
2.7 pb-1
21,000 events
More data coming BES-II is analyzing
additional 12 pb-1 CLEO-c is scheduled to take
50 pb-1 this fall eventually 2
fb-1 (to study D-decays)
y(2S) ? pp- J/y
45k y(3770)
e 37
5.2 pb-1
1.0T
y(3770) ? pp- J/y
232 events
ee- ? g y(2S) y(2S) ? pp- J/y
?
pp-ll- events After cuts on M(ll-) to make
it near M(J/y) or M((2S))
Ecm -Mass recoiling pp-
33
Dipion mass distribution in Belles data
y(2S)
Belle B ? K(J/y pp-)
X(3872)
Scaled sidebands

• Peaking at high values of M(pp-) for y(2S) ?
  J/y(2S) pp- can be explained in the multipole
  expansion model
• For y(1D) ? J/y(2S)pp- the mutipole model
  predicts less pronounced peaking.

T.M.Yan PRD22,1652(1980)
34
Dipion mass distribution

• Data for the new X(3872) state is very strongly
  peaked at high M(pp-) values. Even stronger
  peaking than for 2S ? 1S pp- transitions.
• Fit of the shape predicted for y(1D) ?
  J/y(2S)pp- by Yan gives low confidence level
  0.5
• Either multipole expansion model fails here or
  X(3872) is not a y(13D2) state

X(3872)
Scaled sidebands
X(3872)
Belle data. Rebinned and sideband subtracted by
TS. (not corrected for efficiency)
35
J/y and y(2S) decays at BES
J/y?gpp

• Gateway to light hadron spectroscopy
• rp puzzle
• BES-II has the largest samples (58M J/y , 14M
  y(2S))
• Recent results
• Confirm resonant structure at the pp
  threshold
• Observe cc(1PJ) ?LL. Branching ratios larger than
  expected.
• Improved measurements of J/y and y(2S) ? KS0KL0
  rates

3 5 -10 -25
M1859 MeV G lt 30 MeV/c2 (90 CL)
acceptance
phase space
0
0.2
0.3
0.1
M(pp)-2mp (GeV)
cc(1PJ) ?LL
gt 12
36
(1S), (2S), and (3S), decays at CLEO
(4S) scaled
MC
data

• Can Upsilon decays shed some light at the rp
  puzzle in charmonium?
• CLEO-III has the largest samples (21M (1S), 9M
  (2S), 5M (3S))
• Preliminary results on two-body decays
• Observe signals for (1S) ? ff2(1525) and
  K1(1400)K, BR 10-5
• Set limits for the others
• Tightest limit BR((1S) ? rp)lt 4 10-6 .More than
  (MJ/y /M(1S) )6 suppression relative to the
  charmonium.

Etot/ECM
37
Other BaBar results

• Also
• B ? Khc? K pp pp-
• Mass, width and Gee of (4S)

Comparable rates
38
Summary and Outlook

• Heavy quarkonium physics has been experimentally
  revitalized
• Large data samples collected for quarkonia in
  ee- annihilation by BES-II (cc) and CLEO-III
  (bb). Also E835 pp (cc). Still being analyzed.
• CLEO-c program has started (first y and y
  results from 1 wiggler runs)
• B-gateway to charmonium now wide open with 300M
  B decays at Belle and BaBar
• Similar progress in theory (NRQCD, Lattice QCD)
• Longer range outlook
• Charmonium results from BES-II, CLEO-c/CESR-c (L
  1-5 1032 cm-2 s-1) and later from BES-III/BEPC-II
  (approved in Feb.03! L1033 cm-2 s-1. 2007-)
• Belle and BaBar will continue to produce
  charmonium results from even more B-meson decays
• Charmonium physics from B mesons produced at
  hadronic machines? (Run II, BTeV and LHCb)
• Charmonium at dedicated pp machine? PANDA project
  at GSI (675 M, gt2008-)
• More Upsilon runs at CESR??? Upsilon runs at SLAC
  and KEK???
• X(3872) discovered by Belle is a good looking
  candidate for DD molecule
• Charmonium played crucial role in establishing qq
  model for mesons. It may be now telling us that
  we need to go beyond it to describe all hadronic
  bound state phenomena. Only a heavy quarkonium
  system can provide a convincing proof for
  existence of both forms.