QCD Exotics and Charmonium Klaus Peters Ruhr-University Bochum 2nd Workshop "Challenges and...

QCD Exotics and Charmonium

Klaus Peters

Ruhr-University Bochum

2nd Workshop "Challenges and Opportunities at the New International Accelerator Facility for Beams of

Ions and Antiprotons at Darmstadt

GSI, Oct 15, 2003

3

K. Peters - QCD Exotics and Charmonium

Objects of Interest

Mesons/Baryons

Molecules/Multiquarks

Hybrids

Glueballs

+ Effects due to the complicated QCD vacuum

Quark AntiQuark

5


1.0

1.5

2.0

2.5

qq Mesons

L = 0 1 2 3 4

Each box correspondsto 4 nonets (2 for L=0)

Radial excitations

(L = qq angular momentum)

exoticnonets

0–+

0+–

1++

1+–

1–+

1––

2–+

2+–2++

0–+

2–+

0++

Glu

eballs

Hybrid

s

Lattice 1-+ 1.9 GeV

Light Meson Spectrum

0++ 1.6 GeV

6


Level Mixing

Mixing (Light Quark)broad stateshigh level density

Better:narrow states and/or lower level densitycharmed systems !

Ex

oti

c lig

ht

qq

Ex

oti

c cc

1 - - 1 - +

0 2 0 0 0 4 0 0 0M e V / c2

10 - 2

1

1 0 2

7


Charmed Hybrids

Gluonic excitations of the

quark-antiquark-potential

may lead to bound states

LQCD: -potential of excited gluon fluxin addition to -potential for one-gluon exchangemHc ~ 4.2-4.5 GeV/c2

Light charmed hybrids

could be narrow if open charm

decays are inaccessible or

suppressed

important <r2> and rBreakup

8


Simplest Hybrids

S-Wave+Gluon (qq)8g with ()8=coloured

1S0 3S1

combined with a 1+ or 1- gluon

Gluon 1– (TM) 1+(TE)

1S0, 0–+ 1++ 1––

3S1, 1–– 0+- 0–+

1+- 1–+

2+- 2–+

Meson – Hybrid Mixing

gMIX

gFSI

q

q

Exotic JPC

cannot! be formedby qq

9


LQCD ccg 1-+ vs. cc 1-- (J/)

1-+ m(ccg) Model Group Reference

4390 ±80 ±200 isotropic MILC97 PRD56(1997)7039

4317 ±150 isotropic MILC99 NPB93Supp(1999)264

4287 isotropic JKM99 PRL82(1999)4400

4369 ±37 ±99 anisotropic ZSU02 hep-lat 0206012

(1-+,1--) m(ccg)- m(cc)

1340 ±80 ±200 isotropic MILC97 PRD56(1997)7039

1220 ±150 isotropic MILC99 NPB93Supp(1999)264

1323 ±130 anisotropic CP-PACS99 PRL82(1999)4396

1190 isotropic JKM99 PRL82(1999)4400

1302 ±37 ±99 anisotropic ZSU02 hep-lat 0206012

10


Charmed Hybrid Level Scheme

1-- (0,1,2)-+ < 1++ (0,1,2)+-

JKM00, NPB83Suppl83(2000)304 and Manke, PRD57(1998)3829

L-Splittingm ~ 100-250 MeV/c2

for 1-+ to 0+-

S-Splittings Page thesis,1995 and

PRD35(1987)16684.14 (0-+ ) to 4.52 GeV/c2 (2-+)

consistent w/LQCDJKM, NPB86suppl(2000)397,

PLB478(2000) 1510-+ 4.14

1-+ 4.37

2-+ 4.52

1-- 4.48

4.1

4.2

4.3

4.4

4.5

4.6

4.7

4.8

0+- 4.47

1+- 4.70

2+- 4.85

1++ 4.81

DD**

11


Charmed Hybrid Level Scheme

1-- (0,1,2)-+ < 1++ (0,1,2)+-

JKM00, NPB83Suppl83(2000)304 and Manke, PRD57(1998)3829

L-Splittingm ~ 100-250 MeV/c2

for 1-+ to 0+-

S-Splittings Page thesis,1995 and

PRD35(1987)16684.14 (0-+ ) to 4.52 GeV/c2 (2-+)

consistent w/LQCDJKM, NPB86suppl(2000)397,

PLB478(2000) 151 0-+

1-+

2-+

1--

4.1

4.2

4.3

4.4

4.5

4.6

4.7

4.8

0+-

1+-

2+-

1++

DD**

12


Charmonium Physics

Open questions …

c – inconsistencies

c’ - (2S) splitting

h1c (1P1) unconfirmed

Peculiar decays of (4040)Terra incognita for

any 2P and D-States

… Exclusive Channels

Helicity violationG-Parity violationHigher Fock state contributions

13


The c(11S0)

M(c) = 2979.9 1.0 MeV (c) = 25.5 3.3 MeV

T. Skwarnicki – Lepton Photon 2003

15


The c(21S0) discovery by BELLE

The Belle collaboration has recently

presented a 6 signal for BKKSK

which they interpret as evidence for

c production and decay via the

process:

with:

in disagreement with the Crystal Ball result, but reasonably

consistent with potential model expectations. (DPF 2002).

2

2

M 2978 2(stat) MeV c

22 20(stat) MeV c

= ±

= ±

2

2

M 3654 6(stat) MeV c

15 24(stat) MeV c

= ±

= ±

c c SB K with K K + -¢ ¢® ®

2c

2c

M( ) 3654 6 8 MeV / c

( ) 55 MeV / c

¢ = ± ±

¢ <

16


c(21S0)

BaBar 88 fb-1 Preliminary

Lo

g-s

cale

M(c) = 3637.7 4.4 MeV(c) = 19 10 MeV

T. Skwarnicki – Lepton Photon 2003

17


Quantum numbers JPC=1+-

The mass is predicted to be within a few MeV of the center of gravity of

the c(3P0,1,2) states

Mcog=1/9 {M(c0)+3M(c1)+5M(c2)}

The width is expected to be small(hc) 1 MeV

The dominant decay mode c ( 50 %)

It can also decay to J/:J/0 violates isospinJ/+- suppressed by phase space and angular momentum barrier

Expected properties of the h1c(1P1)

M(h1c) = 3526.2 0.15 0.2 MeV(h1c) < 1.1 MeV

E760

Analysis of E835 data (also in other channels) underway

pph1cJ/0

18


S. Godfrey – QWG03

The hc(1P1)

1P1 vs 3Pcog mass – distinguish models

In QM triplet-singlet splittings test the Lorentz nature of the confining potentialRelativistic effects

important validation of lattice QCD calculationsNRQCD calculations

Observation and precision measurement

of 1P1 states is an important test of theory

19


The X(3872)

New state discovered by Belle inBK (J/+-), J/µ+µ- or e+e-

M = 3872.0 0.6 0.5 MeV 2.3 MeV (90 % C.L.)

X(3872) seen also by CDF

M = 3871.4 0.7 0.4 MeV

20


(11D2) (13D2)

(13D3)

(13D1) DD

J

7%

65%

14%

32%20%

32

32

BR( (1 D ) J / )~ 3

BR( (1 D ) J / )

Based on:E.J.Eichten, K.LaneC.QuiggPRL 89,162002(2002)

Possible interpretations

(13D2)D-states have negative parity, spin-2 states cannot decay to DDThey are narrow as long as below the DD* threshold

(11D2)

preferentially decays to h1c

decays to +-J/ would be of magnetic type and suppressed

WidthSome models predict large widths for (13D2) → +-J/All models predict even larger widths for (13D2) → c2

D0D*0 Molecule ?No model can accomodate (3770) and X(3872) in the same 13DJ triplet.Can coupled channel effects and (13D1)- (23S1) mixing change this ?

21


It is extremely important to identify as many missing states above the open charm threshold as possible and to confirm the ones for which we only have a weak evidence.

This will require high-statisticssmall-step scans of the

entire energy region accessible at GSI.

Charmonium States above the DD threshold

22


3500 3520 MeV3510C

Ball

ev./

2 M

eV

100

ECM

Charmonium Physics

e+e- interactions:Only 1-- states are formedOther states only by

secondary decays (moderate mass resolution)

pp reactions:All states directly formed

(very good mass resolution)

CBallE835

1000

E 8

35

ev./

pb

c1

1,2

J /e e

J /e e

+ -

+ -

® y® gc

® gg y® gg

1,2ppJ /

e e+ -

® c® g y

® g

23


ECM

Resonance Scan

Measured Rate

Beam Profile

Resonance Cross

Section

small and well controlled beam momentum spread

p/p is extremely important

24


Charmonium Physics with pp

Expect 1-2 fb-1 (like CLEO-C)pp (>5.5 GeV/c) J/ 107/dpp (>5.5 GeV/c) c2 (J/ 105/d

pp (>5.5 GeV/c) c‘( 104/d|rec.?

Comparison of PANDA@HESR to E835Maximum energy 15 GeV/c instead of 9 GeV/cLuminosity 10x higherDetector with magnetic field – charged final statesp/p 10x betterDedicated machine with stable conditions

25


Exotics in Proton-Antiproton

Exotics are heavily

produced in pp reactions

High production yields

for exotic mesons

(or with a large fraction of it)f0(1500) ~25 % in 3

f0(1500) ~25 % in 2

1(1400) >10 % in

Crystal Barrel

Interference with other well known (conventional) states is mandatory for the phase analysis

26


Proton-Antiproton @ Rest/Flight

Gluon rich process creates gluonic excitation in a direct waycc requires the quarks to annihilate (no rearrangement)yield comparable to charmonium productioneven at low momenta large exotic content has been proven

Momentum range for a survey pp ~15 GeVBut also Glueball Formation

p

p_

G

M

p

M

H

p_

p

M

H

p_

p

p_

G

p

p_

H

p

p_

H

Production

all JPC available

Formation

only selected JPC

nng ssg/ccg

27


Heavy Glueballs

Light gg/ggg-systems are

complicated to identify (mixing!)

Exotic heavy glueballsm(0+-) = 4140(50)(200) MeVm(2+-) = 4740(70)(230) MeV

Width unknown, but!nature invests more likely in mass than in momentumnewest proof: double cc yield in e+e-

Flavour-blindnesspredicts decays into charmed final states too

Same run period as hybridsIn addition: scan m>2 GeV/c2

Morningstar und Peardon, PRD60 (1999) 034509Morningstar und Peardon, PRD56 (1997) 4043

28


Open charm discoveries

The DS± Spectrum |cs> +c.c. was not expected to reveal any

surprises

Potential model

Old measurements

New observations

0 1 0 1 2 3

Ds

Ds*DsJ*

(2317)

Ds1

m [G

eV/c

2 ]D0K

D*K

DsJ

(2458)

Ds2

JP

29


# 1267 53 Events in peak

# 273 33 Events in peak

M = 2316.8 0.4 MeV = 8.6 0.5 MeV

Resolution from MC is

= 8.9 0.2 MeV

M = 2317.6 1.3 MeV = 8.8 1.1 MeV

DsJ*(2317)+ Ds+0

Ds+ K+K–+0

DsJ*(2317)+ Ds+0

Ds+ K+K–+

Com

bin

ato

rial D

S*+

DS

*+(2

11

2)

BABAR

BABAR

New State in Two Ds+ Modes

30


m = 344.6 ± 1.2 MeV/c2

m = 2456.5 ± 1.4 MeV/c2

Ds* Sideband

m(K+K-+0)- m(K+K-+)

[GeV/c2] [GeV/c2]

m(K+K-+0)- m(K+K-+)

BABARBABAR

DifferenceSignal + Sideband

Search for a Ds+0 State

N = 140 ± 22

31


BF(DsJ(2458)Ds)BF(DsJ(2458)Ds

*)

0.63 0.15 0.15 (continuum) 0.38 0.11 0.04 (B decays)= = 0.47 0.10

Consistent with 1+ hypothesis, 0+, 2+ are excluded

Continuum B decays

DsJ(2458)Ds decay

Belle

Belle

32


Explanation: Chiral doubling?

Ground statesDS

± (JP=0)

DS*± (JP=1) m=144 MeV/c2

have chiral partnersDsJ

*(2317) (JP=?+)

DsJ(2458) (JP=1+) m=141 MeV/c2

PredictionDs1(2536) (JP=1+) and

DsJ(2573) (if JP=2+) m=37 MeV/c2

have also chiral partners at2721±10 MeV/c2 (JP=1) and 2758±10 MeV/c2 (JP=2) m=37 MeV/c2

Nowak, Rho, Zahed

33


4-Quark States, DK Molecules

C=+1, S=+1C=+1, S=+1|D0K+> ≈ |cuus> |csuu> |DS

+π0> + |DS+η>

|D+K0> ≈ |cdds> |csdd> –|DS+π0> + |DS

+η>

|DS+π0> decay of |D0K+> – |D+K0> (I=1)

|DS+η> decay of |D0K+> + |D+K0> (I=0)

|D0K0> ≈ |cuds> |csdu> |DS+π->

|D+K+> ≈ |cdus> |csud> |DS+π+>

C=+1, S=-1C=+1, S=-1|D0K-> ≈ |cuus> |udsuus> |π+K-K->|D+K-> ≈ |cdus> |udsdus> |π+K0K-> |π+KSK->

|D+K0> ≈ |cdds> |udsdds> |π+K0K0> |π+KSKS>

cW+suds

Lipkin, Close, Barnes and others

34


Ds[J][*]± Pairproduction in pp Annihilation

Associated Pair m/MeV/c2 JP Channel (+cc) Final State

Ds(1968.5) Ds (1968.5) 3937.0 0+,1-,2+,3-,4+ Ds+Ds

- 2K-2K++-

Ds (1968.5) Ds*(2112.4) 4080.9 0-,1-,1+,2-,2+,3-,3+,4-,4+ Ds

+(Ds-) 2K-2K++-

Ds*(2112.4) Ds

*(2112.4) 4224.8 0-,0+,1-,1+,2-,2+,3-,3+,4-,4+ (Ds+)(Ds

-) 2K-2K++-

Ds (1968.5) DsJ*(2317.5) 4286.0 0-,1+,2-,3+,4- Ds

+(Ds-0) 2K-2K++-0

Ds (1968.5) DsJ(2458.5) 4427.0 0-,1-,1+,2-,2+,3-,3+,4-,4+ Ds+((Ds

-)0) 2K-2K++-0

Ds*(2112.4) DsJ

*(2317.5) 4429.9 0-,1-,1+,2-,2+,3-,3+,4-,4+ (Ds+)(Ds

-0) 2K-2K++-0

Ds (1968.5) Ds1(2535.4) 4503.9 0-,1-,1+,2-,2+,3-,3+,4-,4+ Ds+(D*-K0) 2K-K+KS+2-(0)

Ds (1968.5) DsJ*(2572.4) 4540.9 0-,1-,1+,2-,2+,3-,3+,4-,4+ Ds

+(D0K-) 2K-2K++-(0)

Ds*(2112.4) DsJ(2458.5) 4570.9 0-,0+,1-,1+,2-,2+,3-,3+,4-,4+ (Ds

+)((Ds-)0) 2K-2K++-0

DsJ*(2317.5) DsJ

*(2317.5) 4635.0 0+,1-,2+,3-,4+ (Ds+0)(Ds

-0) 2K-2K++-20

Ds*(2112.4) Ds1(2535.4) 4647.9 0-,0+,1-,1+,2-,2+,3-,3+,4-,4+ (Ds

+)(D*-K0) 2K-K+KS+2-(0)

Ds*(2112.4) DsJ

*(2572.4) 4684.4 0-,0+,1-,1+,2-,2+,3-,3+,4-,4+ (Ds+)(D0K-) 2K-2K++-(0)

Ds (1968.5) D1*(2770) 4738.5 0-,1-,1+,2-,2+,3-,3+,4-,4+ Ds

+(Ds-+-) 2K-2K+2+2-

DsJ*(2317.5) DsJ(2458.5) 4776.0 0-,1-,1+,2-,2+,3-,3+,4-,4+ (Ds

+0)((Ds-)0) 2K-2K++-20

Ds (1968.5) D2(2870) 4838.5 0+,1-,1+,2-,2+,3-,3+,4-,4+ Ds+((Ds

-)+-) 2K-2K+2+2-

DsJ*(2317.5) Ds1(2535.4) 4852.9 0-,1-,1+,2-,2+,3-,3+,4-,4+ (Ds

+0)(D*-K0) 2K-K+KS+2-(1-2)0

Ds*(2112.4) D1

*(2770) 4882.4 0-,0+,1-,1+,2-,2+,3-,3+,4-,4+ (Ds+)(Ds

-+-) 2K-2K+2+2-

DsJ*(2317.5) DsJ

*(2572.4) 4889.9 0-,1-,1+,2-,2+,3-,3+,4-,4+ (Ds+0)(D0K-) 2K-2K++-(1-2)0

DsJ(2458.5) DsJ(2458.5) 4917.0 0-,0+,1-,1+,2-,2+,3-,3+,4-,4+ ((Ds+)0)((Ds

-)0) 2K-2K++-20

Ds*(2112.4) D2(2870) 4982.4 0-,0+,1-,1+,2-,2+,3-,3+,4-,4+ (Ds

+)((Ds-)+-) 2K-2K+2+2-

DsJ(2458.5) Ds1(2535.4) 4993.9 0-,0+,1-,1+,2-,2+,3-,3+,4-,4+ ((Ds+)0)(D*-K0) 2K-K+KS+2-(1-2)0

DsJ(2458.5) DsJ*(2572.4) 5030.9 0-,0+,1-,1+,2-,2+,3-,3+,4-,4+ ((Ds

+)0)(D0K-) 2K-2K++-(1-2)0

Ds1(2535.4) Ds1(2535.4) 5070.8 0-,0+,1-,1+,2-,2+,3-,3+,4-,4+ (D*+K0)(D*-K0) K-K+2KS2+2-(0-2)0

36


Summary and Outlook

It’s an amazing time in charm spectroscopymany new states – but a lot is missing for a coherent picture

What are the new DsJ stateswhat are their properties like width and decay channels

How do the new cc findings fit into one modellike the new X(3872) state

understand the large width of the cc groundstate C

and the C-(2S) splitting

Where are gluonic excited charmonia (hybrids)spectrum, widths and decay channels

Only high precision experiments can finally

help to solve the puzzle like Panda @ HESR @ GSI

37


Accessible cc-Hadrons at PANDA @ HESR @ GSI

Other exotics with identical decay channels same region

mass and phase spaceof recoil meson forexotic JPC included

conventionalcharmonium

QCD Exotics and Charmonium Klaus Peters Ruhr-University Bochum 2nd Workshop "Challenges and...

Documents

Transcript of QCD Exotics and Charmonium Klaus Peters Ruhr-University Bochum 2nd Workshop "Challenges and...