New Particles from BelleNew Particles from Belle

S. L. OlsenS. L. Olsen((U. of Hawaii)U. of Hawaii)

GHP 2004 Fermilab,GHP 2004 Fermilab, October, 2004October, 2004

B-factory bonuses:

new insights/puzzles in charm/charmonium

spectroscopy

c’

X(3872)

M(KsK)

BK Ks

BK +-J/

M(+-J/

ccc0

J/recoil mass

e+e-J/cc

??‘

BK J/

M(J/

??

bccs is a dominant process

b

c

c

s

Vcb

cosC

J/, ’, c, c1,…

Brs~10-2

(inclusive)

CKMfavored

W-

B mesons are a good source for charm charmonium and other cc states

>900pb-1/day(~1M BBs/day)

1.2x1034/cm2/s

KEKB is a good source of Bs

Kinematic variables for the (4S)

CM energy difference:

Beam-constrained mass:

22 )()2( 'c

ppEm KCMbc

BK c

BKc

2/' cmK EEEEc

B

Bϒ(4S)

Ecm/2

e e

Ecm/2

KSK

KSK

Mbc

E

1st Observation of the c‘

BK (KSK±Ŧ)Mbc for 40 MeV M(KSK) slices

3000 MeV

3640 MeV

BK c

BK c’42fb-1

KSK

KSK

Fit each bin

Nevt = 45.3 ± 12.6 Mc’ = 3653 ± 10 MeV

c’ = 33 ± 22 MeV

Nevt = 90.5 ± 14.9 Mc = 2978 ± 5MeV

c = 33 ± 16 MeV M(KSK)

Mbc E

c:

c’:3.55 GeV

3.60 GeV

3.65 GeV

3.70 GeV

3.75 GeV

…

…

Subsequent measurementsconfirm higher mass value

KSK

KSK

eeJ/X

Mx

BaBar(preliminary)

3630 MeV

3642 MeV

3633 MeV

CLEOhep-ex/0306060

elle

c c‘

c’: current status

Mavg =3637±4 MeV(Crystal Ball excluded)

M(1S) = MJ/ – Mc = 117±1 MeV

M(2S) = 49 ± 4 MeV

smaller

The X(3872) with 253 fb-1

B±K±+-J/ (275M (4S)BB decays)

Nev = 48.6 ± 7.8M = 3872.4 ± 0.7 MeV(width consistent with resol)

Mbc for 5 MeV M(J/) bins

Now M( is really -like

background estimated from Mbc-E sidebands

Confirmed by CDF & D0

PRL 93, 262001(2003) hep-ex/031202

X(3872) X(3872)

CDF D0

hep-ex/0405004

3.5 σ effect

also seen by BaBar

M=3873.4 ± 1.4 MeVB(BKX)B(XJ/) = (1.28± 0.24) x 105

Belle (1.3± 0.3) x 10-5

hep-ex/0406022

X(3872) Mass

D+D*- threshold

(Plot from Soon Yun Jun’s FPCP04 CDF hot topics talk)

Charmonium possibilities

J/c

c’ ’

”

hc

c0c1

c2

c”

hc’c1’

c2

2 3

cc level spectrum

3872 MeVMD+ MD*

2MD

No obvious cc candidates for X(3872)

c”

hc’

c1’

2

c2

3

M too low; too small

c should dominateJ/

J/ decays violate isospin

angular dist’n rules out 1

M too low;J/ too small

c too small; m wrong

c& DD) too small; m wrong

Look at BK J/

M()

M(J

/ )

BK J/

XJ/ BK X(3872);

1: look at BK J/Dalitz Plot

M

Mbc

EM

2(J

/

)

M2(K)

BK* J/K

cut here

Slice into 40 MeV-wide M(J/) bins

Large deviationfrom phase-space

Fit

Slice into 40 MeV-wide M(J/) bins

Adding a BWhelps

FitM≈3940 ± 11 MeV≈ 92 ± 24 MeV

M(K) for the signal region

M(K) (GeV)

3880 <M(J/)<3900 MeV

No peakingIn M(K)

Look back at the masses

76’s28’s

Very clear signal

20’s26’s

What is it? Charmonium?Charmonium?

– Conventional wisdom: J/ should not be a discovery mode for a cc state with mass above DD & DD* threshold!

Some kind of Some kind of -J/-J/ threshold interaction threshold interaction??

– the J/ is not surrounded by brown muck; can it act like an ordinary hadron?

cc-gluon hybrid?cc-gluon hybrid?– Predicted by lattice QCD, including states with large hadron+cc widths,

but the masses are predicted to be 4.3 ~ 4.4 GeV

J/

Evidence for X3872K J/

M(J/) vs M() revisited

M()

M(J

/ )

BK X(3872)

J/

look along here

M(3 J/) = MX(3872) ± 16.5 MeV(±3)

Look at 25 MeV-wide M() mass bins

E Mbc

B-meson yields vs M()

12.4 ± 4.2 evts

“Sidebands”

BKJ/Non-resonant

or “peaking bkgdsidebands

Overlapregion

Cross-talk from BKJ/enhancement?

f dm = 0.75 ±0.14 evts

Check : signal yield for M(3 J/)= M X(3872) +1–3(no overlap with band) 12.4 evts 11.5 evts (expect 11.0 for no X-talk)

Other sidebands(no significant signals)

4.3 ±6.2 evts

6.4 ± 5.6 evts

Area of I and III each= 4x Area of signal bin

Non-res bkd in signal bin = 1.3 ± 1.0 evts

M(K3) for signal bin

Branching fraction

Br(X J/)Br(XJ/)

Nev( J/) (2J/)Nev(J/)(3J/)

=

0.188

0.036

12.4 ± 4.2

62.6 ± 8.3

= 1.1 ± 0.4 (stat) ± 0.3 (syst)

Accept:ance: 10%Xtalk/Bkgnd: -20%X J/: +25%M(3)<750 MeV

significance ≈ 4

Consistent with sub-threshold X(3872) J/

MM + M + MJ/J/ = 3879 MeV (7 MeV above 3872) = 3879 MeV (7 MeV above 3872)

– X J/ occur via virtual ’s, 3 masses cluster at the kinematic limit.

(X(XJ/J/)/)/(X(X J/ J/) = 1.1±0.4 ± 0.3) = 1.1±0.4 ± 0.3

In agreement with Swanson’s DD* bound-state model for the In agreement with Swanson’s DD* bound-state model for the X(3872)X(3872) [PLB 588,189 (2004)][PLB 588,189 (2004)]

Smoking gun for qqqq interpretation of X(3872)?Smoking gun for qqqq interpretation of X(3872)?

- -

continuum e+e-J/ (cc) with 287 fb-1

Details in Tom Ziegler’s talk in session B3Sunday, Snakepit 5:08PM

L=101 fb-1

2002L=155 fb-

1

2003

287 fb -1

c c0

‘c

4th peak!!non-zero continuumbelow DD threshold

• J/ J/ negligible

• confirm c’

• e+e-J/ (cc) > e+e-J/ glue

• (e+e-J/ c) > 10x theory

• evidence for c’ 2004

-

What is the 4th peak?the reconstruction and selection procedure is the same the reconstruction and selection procedure is the same as beforeas before

Extend the fit regionExtend the fit region

no signal of X(3872)significant (>4) peak at M=3940 11 MeVN=14833 (4.5)the width is consistent w/ resolution (= 32 MeV)

X(3872)

c

c

c0

c‘

‘

What is it? c0? c ??‘ “

Look at e+e-J/ D(D(*))

•Reconstruct a J/ & a D•use D0K-+ & D+K-++

•Determine recoil mass

Look at M(DD(*))

DD*

DD

3940 MeV

9.9 ± 3.3 evts(4.5 )

4.1 ± 2.2 evts(2.1 )

c0 DD*‘

c DD“

What is this one?

Is it too narrow to be the same as the Is it too narrow to be the same as the J/J/ peak at 3940 MeV??? peak at 3940 MeV??? under investigationunder investigation– We are looking for J/ recoiling from a J/ in the continuum

– & BK “Y(3940)”; “Y(3940)”DD*

c0c0 or or cc most likely charmonium states most likely charmonium states

– DD* signal rules against c0

– Mass is a little low for c

• M(3S) would be ≈ 100MeV

• can M(3S) > M(2S)?

‘ “

“‘

JP of the DsJ(2317) and DsJ(2457) from BDsJD decays

Details in Alexey Drutskoy’s talk in session C1Monday, 1-West 2:36PM

DsJ(2317) Ds*0

DsJ(2317) Ds0

DsJ(2317) and DsJ(2457)

BaBar - DsJ(2317) CLEO

DSJ(2317)

DSJ(2457)

KKDS

0 KKDS

Masses are significantly lower than potential model P-level predictions - speculations about 4-quark, DK-molecule and Dsπ atom, csghybrid…

DSJ(2317)

M(Ds0)

M(Ds0)

M(Ds*0)

DsJ(2317)Ds0

DsJ(2460) Ds* 0

DsJ(2460)D s

BelleDSJ(2317)

DSJ(2457)

DSJ(2457)

DsJ properties are consistent with two lowerst P-level states

DsJ(2457) consistent with JP=1+ DsJ(2317) consistent with 0+ No Ds0 decay rules out 0+,1- Flat decay angle distribution Ds decay rules out 0+,0- No Ds+ - and Ds decays Helicity in BD DsJ(2457) prefer J=1

J=1

J=2

J=1

J=0

DsJ(2317) Ds0

DsJ(2460) Ds

DSJ(2317)

DSJ(2457)

B D DsJ(2317) (and DsJ(2457))

Summary

cc’ established ’ established M(2S) < M(2S) < M(1S) M(1S) (as expected)(as expected)

(X(3872)(X(3872)J/J/ ≈ ≈ (X(3872) (X(3872) J/J/))– good for molecules; bad for charmonium

Broad near-threshold Broad near-threshold J/J/ peak at 3940 MeV peak at 3940 MeV– too broad for charmonium– too light for cc-glue hybrid?– threshold interaction involving a J/ ?

Narrow(?) peak at 3940 in e+e- Narrow(?) peak at 3940 in e+e- J/J/ X recoils X recoils– May be too narrow to be the J/ state seen in B decays– seen in DD* (rules out c0’)– mass too low to be thec”

DDsJsJ consistent with J consistent with Jpp=0=0++ for D for DsJsJ(2317) (2317) and Jand Jpp=1=1++ for D for DsJsJ(2457)(2457)

Backup Slides

Other results on the X(3872) - Look for X(3872)c2 ( c2

- J/- J/ helicity angle dist inconsistent with J helicity angle dist inconsistent with JPCPC = 1 = 1

- rules out X=21P1 (hc’)

Mbc Mc2

X

2=75/9

|cosJ/

(Xc2)(XJ)

<1.1

- Contrary to expectations for charmonium 3D3

expect: dNdcosJ/

sin2

BKc1; c1J/

no X(3872)Br(XJ/)

Br(XJ/) <0.4

Probably not the c1’

M( J/)-M(J/)

90% CL upper limit:

BK J/

Other new results on the X(3872), cont’d