Heavy Quarkonium Heavy Quarkonium SpectroscopySpectroscopy

Riccardo FacciniRiccardo FacciniUniversity “La Sapienza” and INFN RomeUniversity “La Sapienza” and INFN Rome

Roma, 2 ottobre 2007Roma, 2 ottobre 2007[tratto dal talk ad LP’07][tratto dal talk ad LP’07]

Quarkonium for PedestriansQuarkonium for Pedestrians Quarkonium is a bound state of a quark and an Quarkonium is a bound state of a quark and an

antiquarkantiquark Relevant quantum numbers: n,L,S,JRelevant quantum numbers: n,L,S,J Relationship with Parity and Charge Conj: Relationship with Parity and Charge Conj:

P=(-1)P=(-1)L+1L+1, C=(-1), C=(-1)L+SL+S

Not all JNot all JPCPC allowed allowed (e.g. 0 (e.g. 0+-+-,0,0----,1,1-+-+,2,2+-+- forbidden) forbidden) Decay Properties: :

Below open quark threshold (e.g. (cc)Below open quark threshold (e.g. (cc)DD) only DD) only electromagnetic or electromagnetic or ss suppressed decays allowed suppressed decays allowed mostly narrow statesmostly narrow states

Above open quark threshold (if DD decays allowed)Above open quark threshold (if DD decays allowed) mostly broad statesmostly broad states

What can we learn?What can we learn? Understanding of QCD:Understanding of QCD:

‘‘regular quarkonium’ regular quarkonium’ tests of NRQCD, potential models, tests of NRQCD, potential models, ……

‘‘new states’ new states’ new forms of aggregations mediated by the new forms of aggregations mediated by the strong interactionsstrong interactions

Only charmonium and bottomonium considered hereOnly charmonium and bottomonium considered here

Charmonium: state of the Charmonium: state of the artart

M(M

eV

)

JPC

(2S+1)LJ

Increasing L

Incr

easi

ng n

c

’c

J/

’ c2 c1

c0

hc

Open charm thr.

Recent acquisitions

Basically all states below the open charm threshold are observed and explained

same JPC as J/ but mostly D wave !

(3770)

(4040)

(4160)

(pot. Models)QWG: hep-ph/0412158

Bottomonium: state of the Bottomonium: state of the artart

Open bottom thr. Increasing L

Incr

easi

ng n

Y(1S)

Y(2S)

Y(3S)

Pb{2,1,0}

Pb{2,1,0}

b (x3) completely missing

2 hb and 3 D wave states are narrow but not observed

Y(1D)

8 narrow resonances still missing !

Unconfirmed J assignments of all the b s (pot. Models)

QWG: hep-ph/0412158

Beyond the quarkoniumBeyond the quarkonium Search for states with 2 quarks+”something else” Search for states with 2 quarks+”something else”

New forms of aggregationNew forms of aggregation Expected but never identified!!!Expected but never identified!!!

Hybrids: qq+n gluonsHybrids: qq+n gluons Lowest state 1Lowest state 1-+-+ (forbidden for quarkonium) (forbidden for quarkonium) Dominant decay HDominant decay HDD**DD**

Tetraquarks: [qq’][qq’]Tetraquarks: [qq’][qq’] Large amount of statesLarge amount of states small widths also above thresholdsmall widths also above threshold

Molecules: M[qq]M[q’q’]Molecules: M[qq]M[q’q’] Smaller number of states but still small widths also above Smaller number of states but still small widths also above

thresholdthreshold

Search for resonances:• with non-quarkonium JPC

• unnaturally small widths• not null charge: would be clear indication of something new going on

Measuring the quantum Measuring the quantum numbersnumbers

Production: Production: ISR only produces with same quantum numbers as the ISR only produces with same quantum numbers as the

photon (Jphoton (JPCPC=1=1----) ) only produces with C=+only produces with C=+ Double charmonium productionDouble charmonium production

ee++ee-- **XXcccc11XXcccc

22

Possible only if quantum numbers of the two Possible only if quantum numbers of the two charmonia can be combined to give a 1charmonia can be combined to give a 1----..

Decay:Decay: Angular distributions of decay products depend on JAngular distributions of decay products depend on JPP.. Selection rulesSelection rules

Conservation of JConservation of J Conservation of P,C in strong and e.m. decaysConservation of P,C in strong and e.m. decays

ISR

e+

e- e-

e+

X

e-

e+

X

ExperimentsExperiments

ee++ee-- Charmonium (Charmonium (CLEO-cCLEO-c, , BES-IIBES-II))

L~10L~103333/cm/cm22/s/s E=3.0-4.3 GeVE=3.0-4.3 GeV

ee++ee-- Y(4S): ( Y(4S): (BaBarBaBar, , BelleBelle, , CLEOCLEO))

L~10L~103434/cm/cm22/s/s Charmonium in B decays, ISR and Charmonium in B decays, ISR and production production

Capability to measure JCapability to measure JPCPC also in production also in production pp colliders (pp colliders (CDFCDF, , D0D0))

High Xsection High Xsection copious production copious production Extremely high backgroundsExtremely high backgrounds

3M (2S), 1.8 M (3770)

58MJ/, 14M (2S)

383M Y(4S)

657M Y(4S)

1.5M Y(1S),1.9M Y(2S),1.7M Y(3S),9M Y(4S)

Samples used in results

800pb-1 1.3 fb-1

Disclamers: • time is very short could not cover everything• theory statements are indicative

Quarkonium SpectroscopyQuarkonium Spectroscopy

Updates on 1Updates on 1---- charmonium charmonium statesstates

MeVMeV (3770)(3770) (4040)(4040) (4160(4160))

(4415)(4415)

MM 3771±23771±2 4039±54039±5 4192±4192±66

4415±84415±8

25±725±7 81±1481±14 73±1573±15 73±2173±21

DD not DD*2(2460)

DD*2(2460)

~14σ

improved measurements, including interference for the first time!!!

First exclusive decay observed: DD*

2(2460) [dominant]

3D1 candidateCLEO-c observes (3770)c0Confirms 3D assignment [hep-ex/0605070]

arXiv:0705.4500

Belle-CONF-0771

Y(nS)Y(nS)Y(mS) transitionsY(mS) transitions

The issue:The issue: Quarkonium transitions between Quarkonium transitions between 33SS11 states states

described by the QCD Multipole Expansiondescribed by the QCD Multipole Expansion Tests heavy quark and low energy hadronic systemsTests heavy quark and low energy hadronic systems BR(X(nS)BR(X(nS)X(mS)X(mS))/ BR(X(nS))/ BR(X(nS)X(mS)X(mS))) invariant mass spectra invariant mass spectra simplest PCAC matrix simplest PCAC matrix

element expects enhancement at high masseselement expects enhancement at high masses Data on Charmonium transitions well fitted by Data on Charmonium transitions well fitted by

predictionspredictions Bottomonium physics richer because of larger phase-Bottomonium physics richer because of larger phase-

spacespace Y(2S) and Y(3S) transitions known for yearsY(2S) and Y(3S) transitions known for years

Y(4S) transitions (above open beauty threshold) much Y(4S) transitions (above open beauty threshold) much more difficult [high backgrounds] more difficult [high backgrounds] only recent results only recent results

Y(4S) Y(4S) Y(nS) Y(nS)

As predicted by simplest PCAC matrix elements

PRL 96,232001(2006) Phys.Rev.D75:071103,2007

Low mass structure to be understood!!

Y(4S)Y(1S) Y(4S)Y(2S)

Y(3S) Y(3S) Y(nS) Y(nS) From CLEO’s run @ Y(3S) From CLEO’s run @ Y(3S)

[5x10[5x1066 Y(3S)] Y(3S)] Fit to the Multipole Expansion Fit to the Multipole Expansion

parametersparameters

Results consistent with no ‘C’ Results consistent with no ‘C’ termterm

Breaking of the expansion

The Multipole Expansion model fits the data (but not in its ‘naivest’ form)arXiv:0706.2317

Y(2S)Y(2S)Y(1S) Y(1S) ,,00

Rates predicted by QCD Rates predicted by QCD MEMEBF(Y(2S)BF(Y(2S)Y(1S))=(8.1±0.6)Y(1S))=(8.1±0.6)

1010-4-4

[Kuang hep-ph/0601044][Kuang hep-ph/0601044] Direct search from CLEO Direct search from CLEO

5 5 evidence evidence

BF(Y(2S)BF(Y(2S)Y(1S)) = (2.5±0.7±0.5)10Y(1S)) = (2.5±0.7±0.5)10-4-4

BF(Y(2S)BF(Y(2S)Y(1S)) < 2.1 10Y(1S)) < 2.1 10-4-4

E-m(MeV)

Quarkonium polarizationsQuarkonium polarizationsQCD predicts high pQCD predicts high pTT S-wave quarkonium to be S-wave quarkonium to be

transversely polarized in pp collisions. transversely polarized in pp collisions. Recent updates on J&Recent updates on J&(2S) (CDF) and Y(nS) (2S) (CDF) and Y(nS)

(D0):(D0):

Clear violation of NRQCD for J/, (2S), Y(1S) [Y(2S) follows NRQCD]

LT

LT

2

2

NRQCDCDFPRL88,161802 (2002)

LT

LT

2

2

arXiv:0704.0638

800 pb-1

J/ Y(1S)

BBccK*,hK*,hcc K K(*)(*)

Very little known about dynamics Very little known about dynamics involving hinvolving hcc..

NRQCD predicts NRQCD predicts Br(BBr(BcJcJK(*))~Br(BK(*))~Br(BhhccK(*))~10K(*))~10-4-4

recent measurements:recent measurements:Br(BBr(B00ccKK*0*0)=(6.1±0.8±1.1)10)=(6.1±0.8±1.1)10-4-4

Br(BBr(B++hhccKK++)x Br(h)x Br(hcccc) <5.2 10) <5.2 10-5-5

Br(BBr(B00hhccKK*0*0) x Br(h) x Br(hcccc) <2.4 10) <2.4 10--

44

Suppression in hSuppression in hcc production production [or low Br(hc c)]

arxiv:0707.2843

The new zoologyThe new zoology

X(3872) X(3872) The 1-- family Y(4260)The 1-- family Y(4260) The 3940 family X(3940)The 3940 family X(3940) breaking news breaking news

X(3872): known factsX(3872): known facts DecaysDecays

XXJ/J/ (original observation) (original observation) Maybe J/Maybe J/

BF(XBF(XJ/J/BF(XBF(XJ/J/ XXJ/J/ Implications: Implications:

C(X)=+1C(X)=+1 C(C( in J/ in J/ decay)=-1 decay)=-1 I(I()=L()=L()=1 )=1 consistent with J/ consistent with J/ decay hyp. decay hyp.

ProductionProduction only B decays so faronly B decays so far No prompt eNo prompt e++ee-- production observed (BaBar production observed (BaBar arXiv:0707.1633)

B (X J/ )

B (X J/ )0.19 0.07

Belle+BaBar

Analysis of JAnalysis of JPCPC of X(3872) of X(3872)

Full angular analysis of XFull angular analysis of XJ/J/ decays decays

PRL 98:132002 (2007)

0++

1++

2-+

1--

Only compatible options:JPC=1++ or 2-+ (and with J()=1)

Belle (hep-ex/0505038) disfavours P=- JPC=1++

The X(3872) puzzleThe X(3872) puzzle

Open optionsOpen options DD* moleculeDD* molecule

Right above the thresholdRight above the threshold favours DD* decay over favours DD* decay over

J/J/ over J/ over J/ (as (as observed)observed)

TetraquarkTetraquark Explains small widthExplains small width Predicts a set of 4 states Predicts a set of 4 states

(2 charged and 2 (2 charged and 2 neutral). neutral).

Finding the charged Finding the charged state is criticalstate is critical

M(M

eV

)

JPC

(2S+1)LJIncreasing L

Incr

easi

ng n

c

’c

J/

’ c2 c1

c0

hc

Open charm thr. (3770)

(4040)

(4160)

(pot. Models)

X(3872)?

Not matching any predicted state!

Above DD threshold (allowed): should have large width but it is narrow

Charmonium highly suppressed decay into J/ (isospin violation)

More from theorists…

X(3872)X(3872)DD00DD*0*0

Belle [Belle [PRL 97, 162002 (2006)] observed X(3872)] observed X(3872)DD00DD000 0

Confirmation and integration from BaBar in Confirmation and integration from BaBar in BBDDDD**K K

B+ & B0 D0D*0K

5

1.13.1

10)6.04.07.1(

*);(

)5.02.3875(

DDXXKBBr

MeVM

Mass and BR measurementHints of X in neutral B decays

5

00

10)5.00.12.2(

*);(

)9.17.0(

DDXXKBBr

MeVMWarning!

very low significance

BABAR-PUB-07/049

]06'[10)20.014.1()/;( 5 PDGJXXKBBr N.B.

X(3872): X(3872): and angular and angular analysisanalysis

First info on ≠0 @ 1.3 )

MeV)9.06.3( 6.43.2

cos(Helicity angle)

JP=1+ 1-

2- 2+

First angular analysis (still low stat)

BABAR-PUB-07/049

2

X(3872): update on J/X(3872): update on J/

Update mass and BF in BXK, XJ/B±XK± B0XKS

10.024.094.0)/;(

)/;(

)27.090.022.0(

0

JXXKBBr

JXXKBBr

MeVM

S

Consistent with: no mass difference no rate difference

6.5(first obs.)

Prior results: BaBar PRD73, 011101 (2006)

Belle-CONF-0711

X(3872) massX(3872) mass

Poor agreement Poor agreement among mass among mass measurements:measurements:

XXJ/J/ and and XXDDDD(*)(*) differ by differ by ~4~4

Neutral and Neutral and charged B charged B mesons in mesons in XXJ/J/ by 1.5 by 1.5

TWO STATES? X(3872) & X(3876) ?

Predicted by tetraquark model(but why so close to threshold?)

J/ averageDD average

[my extrapolation]

The new zoologyThe new zoology

X(3872)X(3872) The 1-- family The 1-- family The 3940 family The 3940 family breaking newsbreaking news

The 1The 1---- family familySeveral resonances observed in eSeveral resonances observed in e++ee--

YYISRISR (certainly J(certainly JPCPC=1=1----))

Y(4260)J/

A new state: Y(4260)PRL 95, 142001 (2005)

Confirmation + J/00: CLEO PRD74, 091104 (2006)CLEO-c PRL 96, 162003 (2006)

Yet another state Y(4350)PRL 98, 212001 (2007)

Y(4350)S

The youngest of the 1The youngest of the 1---- familyfamily

MeV155147Γ

9MeV94361M

MeV 3 1584Γ

MeV 5 114664M

NEW

5.8

YSYJ/

MeV44226Γ

MeV404008M8779

7228

MeV19108Γ

MeV124247M810

1726

NEW

Confirmation of BaBar

Zoomed BaBar

arXiv:0707.3699 arXiv:0707.2541

Decay propertiesDecay properties

Y(4350) Y(4660)f0 dominating?Threshold effects?

Y(4008) Y(4260) High mass regionD

EC

AY P

RO

PER

TIE

S

DD(*)(*)DD(*)(*) in ISR in ISR Most of these 1-- states should Most of these 1-- states should

preferentially decay into D(*)D(*) preferentially decay into D(*)D(*) states. Can we see them?states. Can we see them?

(3770), (4040), (4415)[regular charmonia]

clearly visible, nothing else

D*D*

DD*

DD

DDπ,not D(2010,2007)

Basically all R scan other than non-resonant continuum understood

[D(*)D(*)()]

PRL 98, 092001 (2007)

hep-ex/0607083

arXiv:07080082

[Belle: arXiv:07080082]

conti

nuumXse

ctio

n (

pb)

J/J/ KK in ISR KK in ISR Knowledge of the strangeness content of these resonances Knowledge of the strangeness content of these resonances

is critical to disentangle their natureis critical to disentangle their nature CLEO-c already showed few eCLEO-c already showed few e++ee-- Y(4260) Y(4260)J/J/ K K++KK-- Belle (ISR): first observation of eBelle (ISR): first observation of e++ee-- J/ J/ K K++KK-- and J/ and J/ K KssKKss

e+e- e+e- J/ J/ K K++KK--

e+e- e+e- J/ J/ K KSSKKSS

CLEO-c@4260

(e+e- J/KsKs)/ (e+e- J/K+K-)=0.6+0.5-0.4

Consistent with isospin (0.5)BELLE-CONF-0772

11-- -- family: recapfamily: recap

Not matching Not matching any potential any potential model model predictionprediction

Too narrowToo narrow

M(M

eV

)

JPC

(2S+1)LJ

J/

’Open charm thr. (3770)

(4040)

(4160)

(pot. Models)

1--

4008426043504660

Only seen in (2S)

1--

“new physics”?

4260 can be fit by a tetraquark model (decaying into J/f0 …) or a hybrid (with g)

4 Ys to place !

Why not the ordinary Y(4040)?

The new zoologyThe new zoology

X(3872)X(3872) The 1-- family The 1-- family The 3940 family The 3940 family breaking newsbreaking news

The 3940 familyThe 3940 familyObserved inObserved in JJPC PC (?) (?) M M (MeV)(MeV) (MeV)(MeV)

XX ee++ee--J/J/X (XX (XDDDD**)) 00-+-+,1,1++++ 3943±83943±8 <39<39

YY BBYK (YYK (YJ/J/ 11++++,…,… 3943±13943±177

87±3487±34

ZZ Z (ZZ (ZDD)DD) 22++++ 3929±53929±5 29±1029±10

ZDDYJ/

XDD*

PRL 96, 082003 (2006)PRL 94, 182002 (2005)PRL 98, 082001 (2007)

Confirmation of Y(3940) Confirmation of Y(3940) (B(BKKJ/J/ +-0

BYK

B0YKS

B0/B

Isospincons.

New result, based on 350 fb-1:

Belle’s evidence for BYK, YJ/ confirmed

~30MeV lower mass than Belle’s

Narrower width

Clear demonstration of decay into Preliminary BF estimate similar to Belle’s (~10-5)

preliminary

G. Cibinetto, talk at this conference

M(J/) (GeV)

Y(3940) closer to X(3940)Can they be the same state?

““Just” charmonium states?Just” charmonium states?M

(MeV

)

JPC

(2S+1)LJ

Open charm thr. (3770)

c1

(pot. Models)

c2

c0’c

c

X Z

X,Y

Poor match Poor match with predictionswith predictions Above Above

threshold?threshold? If X≠Y, difficult If X≠Y, difficult

to explain to explain absence of absence of YYopen charmopen charm Hybrid?Hybrid?

The new zoologyThe new zoology

X(3872)X(3872) The 1-- familyThe 1-- family The 3940 family The 3940 family breaking news!!breaking news!!

DD* D*D*

D

D*

X(4160)X(4160) D D**DD**

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

Obtain J/D(*)D(*) samples through kinematic separation, look at m(D(*)D(*))after background subtraction: M = 3942 ±6 MeV

tot =37 ±12 MeV

Nev= 52 ±11

Inferred (Recoil mass)

X(4160)X(4160)

claim: claim:

new new statestate

M = 4156 ±15MeV

tot = 37 ±21MeV

Nev= 24

+25- 20

+111 - 61

+12 - 8

5.5

3.8

X(3940)X(3940)

Cross-checkCross-check

X(3940)X(3940)

is still there,

is still there,

6.06.0

Something’s

here, but it’s

not X(3940)

M(DD)

M(D*D*)

M(DD*)

M(D*D)

J/ D+

J/ D*+

Num

ber

of e

vent

s

One more particle to explain … JCP=0-+ not excluded (c(3S))

reconstructed

BELLE-CONF-0705

The first charged state: The first charged state: Z(4430)! Z(4430)!

B±Z±Ks or B0ZK±

Z±(2S)±

Total significance: 7.3s

M = (4433±4) MeV= (44+17

-13) MeV

BF(BKZ)xBF(Z(2S))=(4.1±1.0±1.3) 10-5

Xcheck: separate in subsamples

BF and mass consistent between B± and B0 within large errors [in B± decays M=(4430±9) MeV ; BF±/BF0=1.0±0.4 ]

Too narrow to be a reflection

Prior search with no evidence: BX+K with X+J/0 PRD 71, 031501 (2005)

BELLE-CONF-0773

SummarySummaryM

(MeV

)

JPC

(2S+1)LJ

Open charm thr. (3770)

(4040)

(4160)

(pot. Models)c

’c

J/

’ c2 c1

c0

hc

X Z

X,YX(3872) the best tetraquark candidate

Updated properties

(4415)

The 1-- family:Charmonia, tetraquarks, molecules, hybrids?!?

News on the 3940 family

+ updates on Y(nS)Y(mS) transitions

Yet another particle: X(4160) [c(3S)?]

Z(4430): the first charged state

Thresholds and new statesThresholds and new states

X(3872)

Y(4260)

X(4160)

XYZ(3940)

Y(4350)

Y(4660)

Z(4430)

Molecular models and threshold effects require vicinity to threshold

Is this the case?

The observation matrixThe observation matrix

J/J/ DD(*)(*)DD(*)(*) J/J/ J/J/ (2S)(2S) J/J/K,K, SS J/J/

NotesNotes Mass Mass range range for B for B

Low Low statstat

No ISR No ISR studystudy

Mass Mass range!range!

No ISRNo ISR

No ISRNo ISR

No No 00

No No SearcSearchh

No B-No B-decdec

Mass Mass windowindoww

X(3872X(3872))

SeenSeen SeenSeen Not Not seenseen

Not Not seenseen

Not Not seenseen

No No searcsearchh

N/AN/A SeenSeen

Y(3940Y(3940))

No No searchsearch

X(3940X(3940)?)?

SeenSeen No No searchsearch

Not Not seenseen

No No searcsearchh

No No searchsearch

No fitNo fit

Y(4260Y(4260))

SeenSeen No fitNo fit No fitNo fit No No searchsearch

No No searchsearch

No No searcsearchh

Not Not seenseen

N/AN/A

Y(4350Y(4350))

Not Not seenseen

No fitNo fit No fitNo fit No No searchsearch

No No searchsearch

No No searcsearchh

SeenSeen N/AN/A

Z(4430Z(4430))

No No searchsearch

No No searchsearch

No fitNo fit No No searchsearch

SeenSeen No No searcsearchh

No No searchsearch

No No searchsearch

Y(4660Y(4660))

Not Not seenseen

No fitNo fit No fitNo fit No No searchsearch

No No searchsearch

No No searcsearchh

SeenSeen N/AN/A

Comments & PerspectivesComments & Perspectives

No systematic search on present B-Factory dataNo systematic search on present B-Factory data Groups working on this shrinking, should be revitalizedGroups working on this shrinking, should be revitalized Also Tevatron has some homework (e.g. bottomonium Also Tevatron has some homework (e.g. bottomonium

spectroscopy)spectroscopy) Data involving D mesons have low stat (e.g. Data involving D mesons have low stat (e.g.

Br(Y(4260)Br(Y(4260)DD)/Br(Y(4260)->J/DD)/Br(Y(4260)->J/)<6.7 @95% )<6.7 @95% C.L. – BaBar prelim)C.L. – BaBar prelim) 100 times the stat would help 100 times the stat would help SuperB or SuperB or

intermediate?intermediate? Hadron colliders have limited power:Hadron colliders have limited power:

cannot do all the needed final statescannot do all the needed final states Limited capability at measuring JLimited capability at measuring JCPCP

SummarySummaryM

(MeV

)

JPC

(2S+1)LJ

Open charm thr. (3770)

(4040)

(4160)

(pot. Models)c

’c

J/

’ c2 c1

c0

hc

X Z

X,YX(3872) the best tetraquark candidate (?)

Updated properties

(4415)

The 1-- family:Charmonia, tetraquarks, molecules, hybrids?!?

News on the 3940 family

+ updates on Y(nS)Y(mS) transitions

Yet another particle: X(4160) [c(3S)?]

Z(4430): the first charged state

WHAT

A M

ESS

!!!!

( of d

ata)

The discovery and identification of a new spectroscopy

seems close

Rim

bocc

hiam

oci

le m

aniche

bakupbakup

Fits to J/Fits to J/ KK invariant mass KK invariant mass‘Standard ‘ y(4415) + 1 BW:M = (4875±132) MeV = (630±126) MeV

single BW:M = (4430±38) MeV = (254±49) MeV

CLEO and Belle on 4260CLEO and Belle on 4260

Search for Search for X(3872)X(3872)J/J/ in in continuumcontinuum

X>2 ch

c production is consistent with the expected contributions from prompt (2S) production feed-down to c: no evidence of prompt c1,2

No evidence of X(3872) production in e+e- annihilation.

c1,2 or X(3872)

c1

c2

X(3872)

386fb-1

J/ production observed in continuum while no evidence of c states.

arXiv:0707.1633

Below open charm thresholdBelow open charm threshold