cc spectroscopy at elle

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cc spectroscopy at elle
_
S.L.Olsen Hawaii
QWG 2004 Worksop IHEP Beijing
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B-factory bonuses
new insights/puzzles about charmonium
B?K KsKp
B?K pp-J/y
hc
X(3872)
M(KsKp)
M(pp-J/y)
ee-?J/y cc
B?K wJ/y
??
??
hc

cc0
hc
J/y recoil mass
M(wJ/y)
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b?ccs is a dominant process
CKM favored
J/y, y, hc, cc1,
c
Vcb
c
b
W-
Brs10-2 (inclusive)
cosqC
s
B mesons are a good source for charmonium and
other cc states
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KEKB is a good source of Bs
gt900pb-1/day (1M BBs/day)
1.2x1034/cm2/s
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(No Transcript)
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Kinematic variables for the ?(4S)
B?K hc

Ecm/2
KSKp
e-
e
B? ?B
?(4S)
Ecm/2
DE
CM energy difference
B?K hc
KSKp
Beam-constrained mass
Mbc
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1st Observation of the hc

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B?K (KSKpT)Mbc for 40 MeV M(KSKp) slices
3640 MeV
B?K hc
42fb-1
KSKp
B?K hc
3000 MeV
KSKp
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Fit each bin

Nevt 45.3 12.6 Mhc 3653 10 MeV Ghc
33 22 MeV
3.55 GeV
hc
3.60 GeV
3.65 GeV
3.70 GeV
3.75 GeV
Mbc
DE

Nevt 90.5 14.9 Mhc 2978 5MeV Ghc
33 16 MeV
hc
M(KSKp)
S.K. Choi et al PRL 91, 102001
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Subsequent measurementsconfirm higher mass value
gg?KSKp
gg?KSKp
3642 MeV
BaBar (preliminary)
CLEO hep-ex/0306060
ee-?J/yX
3630 MeV
3633 MeV
elle
hc
hc

Mx
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hc current status
Mavg 36374 MeV (Crystal Ball excluded)
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DM(1S) MJ/y Mhc 1171 MeVDM(2S) 49 4
MeV
gets smaller
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The X(3872) with 253 fb-1
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B?Kpp-J/y
Nev 48.6 7.8 M 3872.4 0.7 MeV
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Now M(pp-) is really r-like
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X(3872) Mass
DD- threshold
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Look at B?K pp-p0 J/y
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B?K w J/y
w?pp-p0
M(J/y pp-p0)
X?J/y pp-p0?
B?K X(3872)
M(pp-p0)
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1 look at B?K w J/yDalitz Plot
Mbc
cut here
M2(J/y w)
DE
B?K J/y
?Kw
Mpp-p0
M2(Kw)
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Slice into 40 MeV-wide M(w J/y) bins
Large deviation from phase-space
Fit
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Slice into 40 MeV-wide M(w J/y) bins
Adding a BW helps
Fit
M3940 11 MeV G 92 24 MeV
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M(Kw) for the signal region
3880 ltM(wJ/y)lt3900 MeV
No peaking In M(Kw)
M(Kw) (GeV)
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Look back at the pp-p0 masses
Very clear w signal
28ws
76ws
20ws
26ws
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What is it?

• Charmonium?
• Conventional wisdom wJ/y should not be a
  discovery mode for a cc state with mass above DD
  DD threshold!
• Some kind of w-J/y threshold interaction?
• the J/y is not surrounded by brown muck can it
• act like an ordinary hadron?
• cc-gluon hybrid?
• Predicted by lattice QCD, including states with
  large hadroncc widths, but predicted masses are
  4.4 GeV

w
J/y
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Next B?K X(3872)
?pp-p0 J/y
M(J/y pp-p0)
look along here
B?K X(3872)
?J/y pp-p0
M(pp-p0)
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M(3p J/y) MX(3872) 16.5 MeV
(3 s)
Look at 25 MeV-wide M(pp-p0) mass bins
Mbc
DE
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B-meson yields vs M(pp-p0)
12.4 4.2 evts
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Sidebands
B?KwJ/y
Non-resonant or peaking bkgd sidebands
Overlap region
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Cross-talk from B?KwJ/y enhancement?
? f dm 0.75 0.14 evts
Check signal yield for M(3p J/y) M X(3872)
1s/3s (no overlap with w band) 12.4 evts ?
11.5 evts
(expect 11.0 for no X-talk)
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Other sidebands(no significant signals)
4.3 6.2 evts
Non-res bkd in signal bin 1.3 1.0 evts
6.4 5.6 evts
Area of I and III each 4x Area o signal bin
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Branching fraction
0.188
13.1 4.2
Br(X?pp-p0 J/y) Br(X?pp-J/y)
Nev(pp-p0 J/y) e(2pJ/y) Nev(pp-J/y)e(3pJ/y)

62.6 8.3
0.036
1.1 0.4 (stat) 0.3 (syst)
Acceptance 10 Xtalk/Bkgnd -20 X?pp-p0
J/y 25 M(3p)lt750 MeV
significance 4s
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Consistent with sub-threshold X(3872)?w J/y

• Mw MJ/y 3879 MeV (7 MeV above 3872)
• X?w J/y occur via virtual ws, 3p masses cluster
  at the kinematic limit.
• G(X?wJ/y)/G(X?pp- J/y) 1.1 0.4 0.3
• In agreement with Swansons DD bound-state model
  for the X(3872) PLB 588,189 (2004)
• Smoking gun for qqqq interpretation of X(3872)?

- -
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update continuum ee-?J/y (cc) with 287 fb-1
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2002
2003
L101 fb-1
L155 fb-1
-

• gg?J/y J/y negligible
• confirm hc

• ee-?J/y (cc) gt ee-?J/y glue
• s(ee-?J/y hc) gt 10x theory
• evidence for hc

2004
287 fb -1

hc
hc
cc0
non-zero continuum below DD threshold
4th peak!!
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What is the 4th peak?

• the reconstruction and selection procedure is
  the same as before
• Extend the fit region
• no signal of X(3872)
• significant (gt4s) peak at M3940 ? 11 MeV
• N148?33 (4.5?)
• the width is consistent w/ resolution ( 32 MeV)

X(3872)
hc

hc

cc0
hc
What is it? cc0? hc ??


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Look at ee-?J/y D(D())

• Reconstruct a J/y a D
• use D0?K-p D?K-pp
• Determine recoil mass

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Look at M(DD())
3940 MeV
9.9 3.3 evts (4.5 s)
DD
cc0 ?DD

DD
4.1 2.2 evts (2.1 s)
hc ?DD

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What is this one?

• Too narrow to be the same as the wJ/y peak at
  3940 MeV
• cc0 or hc most likely charmonium states
• DD signal rules against cc0
• Mass is a little low for hc
• DM(3S) would be 100MeV
• can DM(3S) gt DM(2S)

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Summary

• hc established DM(2S)ltDM(1S)
• G(X(3872)?pp-p0J/y G(X(3872) ?pp- J/y)
• Good for molecules bad for charmonium
• Broad near-threshold wJ/y peak
• too broad for charmonium
• Too light for cc-glue hybrid?
• theshold interaction involving a J/y ?
• 4th peak seen in ee- ? J/y X
• Evidence for it in DD (rules out cc0)
• If it is the hc, DM(3S) gt DM(2S)

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X(3872)?pp-p0J/y
Y(3940)?wJ/y
3D2?? hc??
ee-?J/y X(3940)
B-factory data
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M(K3p) for signal bin
Events at M(3p)775 MeV Kinematic limit would
peak here