a. drutskoy university of cincinnati

A. Drutskoy University of Cincinnati

Charm spectroscopy

April 14-17, 2007, Jacksonville, Florida .

American Physical Society Meeting

Charm spectroscopy, APS meeting, Apr 14 -17, 2007, Jacksonville, Florida, A. Drutskoy

1

Outline

Charmonium state X(3872).

Experimental results and classification of DsJ mesons.

Meson classification, potential models.

Charmonium states X(3940), Y(3940) and Z(3930).

Recent experimental results on excited D** production.

New charmonium states Y(4260) and Y(4320).

New charm baryons.

Conclusions.


2

CLEO

http://www.slac.stanford.edu/BFROOT/BABAR.html

Conventional and unconventional mesons

1. Conventional quark- antiquark mesons (qq).

2. Glueballs (gg, ggg). Lightest glueballs JPC = 0++ and 2++.

3. Hybrid mesons (qqg). Ground states JPC = 0- +, 1- +, 1- -, 2- +.

4. Tetraquarks (qqqq). Large binding energy. Non-qq flavor?

5. Molecular states (qq qq). Small binding energy. Deuteron-like.

6. Mixture of these states.

Coupled-channel effects. If Mres close to M1+M2 mass shift?

These states can be separated using information on masses,widths, quantum numbers, production and decay modes (rates).


3

Theoretical calculations, potential models, lattice calculations.

Potential models, energy splitting

cc

LL (S1 S2)

L=00-1-

L=1

J/c

hc1+

2S1- ’

’c

1S

c0

c1

c2

1+

0+

2+

cq

L

(L S2) S1Jq

Mas s

L=0

S12

L=1

Jq=3/2

Jq=1/2

0-1-

Ds

Ds*

D’s0

Ds1

0+

1+1+

2+

D’s1

Ds2

2S

1S

0- 0-1-

1P 1P


4

s1s2 s2

s1

Jq is a good quantum number =>

separated D(s) meson spin-doublets: (0-,1-),

(0+,1+), (1+,2+).

Energy splitting: singlet and triplet.


5D**0 and D**+ meson searches

~388M

hep-ex/0611054(2006)

No restrictions onD** quantum numbersin B decays.

D** mesons are studiesusing fully reconstru-cted B meson decays.It provides strong background suppression.

(2465.71.80.8 ) MeV/c21.24.7

(49.73.84.1 4.9) MeV

Orbitally excited D**0 and D**+ mesons

Theory and experimentare in good agreement


6

DsJ meson spectroscopy

+ +

*Ds

DsDsJ(2317)

DsJ(2460)

DsJ(2536)

DsJ(2573)

Many theoretical papers have been published since 2003, trying to explain narrow DsJ(2317) and DsJ(2460) resonances: chiral partners, DK threshold effect, four-quark states?

Measured masses of DsJ(2317) andDsJ(2460) are significantly lower thanthose predicted in potential models.Their quantum numbers 0+ and 1+

are well established now.


7

■ B+→D0DsJ(2700) ■ B+→ψ(3770)K+ ■ B+→ψ(4160)K+ ■B+→D0D0K+NR

■threshold contribution

fitted B signal

hep-ex/0608031

New DsJ(2700) meson in B+ >D0D0K+ decay

449M BB


8

DsJ(2700)

J=0 2/ndf = 185/5J=1 2/ndf = 7/5 J=2 2/ndf = 250/5

eff. corrected DsJ(2700) helicity angle distribution

cs radial excitation 23S1 ?(predicted by potential modelsat M~2720MeV) ?or chiral symmetry doublet?

JP=1- is favored.

DsJ(2700) helicity angle distribution


9

−+++−++−+

+−+−+

+−+−+

→→→

→→

→→

ππππππ

π

00

000

00

, ,

,

,

ss KKDXKDee

KDXKDee

KDXKDee

240 fb-1103

hep-ex/0607082

New DsJ(2860) meson in e+e- >D0K+X, D+K0X

M(DK) (GeV/c2)

BG subtracted

DsJ(2860)

2

2

MeV/c 10747))2860((

MeV/c 0.55.16.2856))2860((

±±=Γ

±±=

sJ

sJ

D

DM

Hint of a broad stateat 2.69 GeV/c2

Strong peak at2.573 GeV/c2


10

=>New resonance at 2.86 GeV/c2


DsJ meson spectroscopy

Ds

Ds*DsJ(2317)

DsJ(2460)

DsJ(2536)

DsJ(2573)

Ds(2700) ?DsJ(2860) ??

Is Ds(2700) state theradial excitation 23S1

(predicted by potential models at M~2720MeV) ?

Is DsJ(2860) state theradial excitation of DsJ(2317) ?

DsJ(2700) : Jp = 1-

DsJ(2860) -> D0 K+ (0-0- )


11

Charmonium spectroscopy

MD*+MD

2MD

c

J/

c0

c1

c2hc

’

c’’

hc’

c1’

c2

c’

12


cc

blue lines: predictions

black lines: measurements

))(()2( 0cchS γγγπψ →→

With Inclusive c decay

M(π0 recoil) (GeV)

15040 eventsstat. sig. 3.8

3.08M ψ(2S)

hc

CLEO

CLEO PRL 95 (2005) 102003CLEO PRD 72 (2005) 092004

M(hc)=3524.90.70.4 MeV/c2

hc(1P1) and c(2S) charmonium states

Belle PRL 89 (2002) 102001BaBar PRD 92 (2004) 142002

Belle first observed c(2S) at B-> K(KsK+π-) and then at e+e- -> J/ψ X

c(2S) was then confirmed by CLEO and BaBar

MPDG=3637.7±4.4MeV/c2

B→ K(KsK+π)

13


ψ’

Eve

nts

/10

MeV

Belle

X(3872)

X(3872)230 pb-1

PRL 91 (2003) 262001

304M B’s

PRL 93 (2004) 072001

PRL 93 (2004) 162002

BaBar

ψ’X(3872)

220 pb-1

M(J/ψ π+π-)

X(3872)

X(3872) > J/ψ π+π- decay

First observed by Belle in B± -> K±(J/ψπ+π-).Then confirmed by CDF, D0 and BaBar.

PRD 71 (2005) 071103

234M B’s

14



Belle/BaBar average:

13.6 4.4 events stat. sig.: 4.0

It suggests that C parity of X(3872) is +1

X(3872)

MγJ/ψ (GeV/c2)

275M BB

hep-ex/0505037

X(3872)

PRD 74 (2006) 071101R

287M BB

19.4 5.7 events stat. sig.: 3.4

MγJ/ψ (GeV/c2)

07.019.0)/)3872((

)/)3872((±=

→Γ→Γ

−+ ψππψγJX

JX

Evidence for X(3872) > γ J/ψ 15


Low γ J/ψ rate > bad candidate for ’c1 ??? (1++).


X(3872) : C=+1

275M BB10.63.6 events4.3

hep-ex/0505037

3.04.00.1)/)3872((

)/)3872(( 0

±±=→Γ

→Γ−+

−+

ψππψπππ

JXJX

Evidence for sub-threshold X(3872) > J/ψ

no signals for charged partners of X(3872) (BaBar) no signal for X(3872) -> J/ψ (BaBar) no evidence in γγ fusion and radiative production (CLEO)

B±-> K±(J/ψ π+π-π0)

M(π+π-π0) (GeV/c2)

16


X(3872) quantum numbers

Angular distributions in B->X(3872)K decay X(3872) -> J/ π+ π- : favors 1++.

2/d.o.f=11/92/d.o.f=11/9

2/d.o.f=5/9 2/d.o.f=5/9

|cos|cosll||

|cos|cos||

1++

Hint for B->X(3872)K with X(3872)->D0D0π0

favors 1++ (disfavors 2++) (next slide).

1++

PRL 96 (2006) 102002

Preference for high π+π- mass region. Possible interpretation: X(3872)->J/ψ Possible X(3872) quantum numbers:

Jp=1++ (or 2-+) .

hep- ex/0505038


17

DD*

DDX(3872)

X(3872) interpretation ?

Interpretation of X(3872) is unclear. Molecular interpretation ?


18

< 1 MeV/c2

If X(3872) is a loosely bound S wave D0D0* molecule, an enhancementin the near threshold D0D0* invariant mass spectrum is expected.

24.07.1 MeV/c 9.07.04.3875 ±±= +

−M

PRL 97 (2006) 162002

414 fb-1

• 23.4 5.6 events• 6.4

6.33.4

0*0

4.9)/(

)( +−=

→Γ→Γ

ψππJXDDX

If it is X(3872), J=2 is suppressed, JPC=1++ is favored.

Near threshold D0D0π0 enhancement in B >D0D0π0K

X(3872) -> D0D0* production rate is large. This is difficult toexplain within molecular interpretation.


19

M = 3875.2 0.7 +0.3 0.8 MeV/c2-1.6

=8.8+3.1-3.6

S-wave D0D*0:

E. Braaten et al., PRD 71, 074006

00 )3872( sKXB →−−→ KXB )3872(

6.1 2.5

2

0

MeV/c 0.21.32.7

C.L. 90%at 10.113.0

±±=

<≡< −

ÄM

BBR

PRD 73 (2006) 011101 R

232M BB

1.0<R

X(3872) in B0 and B+ decays

B+

K+

D0

D*0X(3872)

Data are not in favor of this model.

20



357 fb-1

Mrecoil(J/ψ)

M = (3943 6 6) MeV/c2

Γ < 52 MeV/c2 (90% C. L.)Stat. sig. > 5.0 above DD and D*D thresholds

PRL 98 (2007) 082001

Observation of X(3940) in e+e- > J/ψ X

J/ψ

X

e- e+

> JPC = 1++ is preferred, candidate ’c1 (or c(3S) ? ).

D*D is the dominant decay of X(3940)

21


not seen in DD and J/ψ

253 fb-1

If it is treated asa S-wave BW:

M = 3943 11 13 MeV/c2

Γ = 87 22 26 MeV/c2

2/d.o.f.=15.6/8stat. sig.=8.1

PRL 94 (2005) 182002

-> above D*D threshold

-> not found in DD or D*D final states

Y(3940) > J/ψ near threshold peak in B >K J/ψ22

M(J/ψ)

2/d.o.f.=115/11


PRL 96 (2006) 082003 395 fb-1

D0D0 + D+D-

Z(3930)

Search for cJ via γγ >DD and Z(3930)., 23

Good candidate for ’c2

Angular analysis favors J=2


N sig. = 64 18 stat. signif. 5.3 M=3929 52 MeV/c2

Γ=29 102 MeV/c2

)or ( /ISR−+−+−+−+ →→ μμψππγ ee/J øJee

Y(4260)

Observation of Y(4260) in ISR events and B decays

233 fb-1

PRL 95 (2005) 142001

CLEO

PRD 74 (2006) 091104

4.9 sig.

13.3 fb-1

hep- ex/0612006

553 fb-1

First observed by BaBar, then confirmed by CLEO and Belle.

B->Y(4260)KY(4260)-> J/ψ

π+π-

Jp = 1--

3.1 sig.PRD 73 (2006) 011101

24




BaBar CLEO III Belle

N 125 23 (~8)

14.1 +5.2 (4.9) 165 24 ( >7)

Mass(MeV/c2)

4259 8 +2 4283+17 4 4295 10 +10

Width(MeV/c2)

88 23 +6 70 +40 5 133 26 +13

-6

-4

-4.2

-16

-25 -6

-3

1-- state, but not seen in e+e- -> hadrons (local

minimum).

25What is the Y(4260) state ?

different

Interpretations:

• Hybrid charmonium: Zhu, PLB 625 (2005) 212; Close & Page, PLB 628 (2005) 215; Kou and Pene, PLB 631 (2005) 164; Luo and Liu, PRD 74 (2006) 034502, …

• Tetraquark: Ebert et al., PLB 634 (2006) 214; PRD73(2006)094501, ...

• Molecules: Liu et al., PRD 72 (2005) 054023 (R); Yuan et al., PLB 634 (2006) 399 Qiao, PLB 639 (2006) 263, …

• Conventional: F. J. Llanes-Estrada, PRD 72 (2005) 031503(R), …


hep- ex/0610057Y(4260) Y(4350) 3-body phase space

If this peak is a single resonance:2

2

MeV/c 23172

MeV/c 244324

±=Γ

±=M

M(π+π-ψ(2S)

What is Y(4320)?

Observation of Y(4320) >π+π-ψ(2S) in ISR events 26



DD*

DDX(3872)

Y(4320)Y(4260)

What are X(3872), Y(4260) and Y(4320) ?


Currently on market: X(3872) -molecular, Y(4260) & Y(4320) - hybrids

27

D0 mass sidebands

Charmed baryons

c(2940)+

c(2880)+

hep-ex/0603052

2

2

MeV/c 9.52.55.17

MeV/c 0.13.18.2939

:)2940(

±±=Γ

±±=

+

Mc

Inclusive D0p mass spectrum

287 fb-1

c(2980)+ : M=2978.52.12.0 MeV/c2

Γ=43.5 7.57.0 MeV/c2

Mass(Λc+ K- π+)(GeV/c2)

cx(2980)+

cx(3077)+

hep-ex/0606051

Many new charm baryon resonances

Belle<>BaBar confirmed


28


Conclusions29


Many new open charm and charmonium (charmonium-like) states are observed (DsJ(2700), DsJ(2860), X(3872), X(3940),

Y(3940), Z(3930), Y(4260), Y(4320), baryons… ).

Interpretation of some of these states is not clear. New ideas on market: four-quark states, molecular states, hybrids.Maybe some mixture of two-quark and unconventional states?

It is theoretically difficult to explain some measurementsof production and decay rates for some (even conventional)states (no time to discuss it in this talk).

It is important to determine quantum numbers of all observed states. More decay channels should be studied.

a. drutskoy university of cincinnati

Documents

aps meeting

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drutskoy 8dsj2700j

b d0dsj2700 b

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quark states