qiang zhao institute of high energy physics, cas, p.r. china

Post on 19-Mar-2016

30 Views

Category:

Documents

3 Downloads

Preview:

Click to see full reader

DESCRIPTION

Charm 2006, Beijing, June 6, 2006. Mixing of scalar meson and glueball. Qiang Zhao Institute of High Energy Physics, CAS, P.R. China “Scalar puzzles” from the recent exp. data Scalar glueball and QQ* mixing Mechanisms for scalar meson productions in - PowerPoint PPT Presentation

TRANSCRIPT

Qiang ZhaoInstitute of High Energy Physics, CAS, P.R. China

• “Scalar puzzles” from the recent exp. data• Scalar glueball and QQ* mixing • Mechanisms for scalar meson productions in (i) J/ V f0 V PP ( V= , ; P = , , , K), (ii) c0 PP, VV, f0 f0. • Summary

Mixing of scalar meson and glueball

Charm 2006, Beijing, June 6, 2006

In collaboration with Frank Close and Bing-song Zou

Exotic type 1: Mesons have the same JPC as a QQ*, but cannot be accommodated into the SU(3) nonet: 3 3* = 8 1

3 4 1 1

I=0

f0(980)(958)

(547)(782)

(1020)

/f0(600)

f0(1370)f0(1500)

f0(1710)

0 1 0

Multiquarks? Meson molecule ?

Glueball ?QQ*-glue mixing ?

Mas

s

f0(1790)f0(1810)M. Chanowitz

Experimental signals for scalar mesons

• Crystal Barrel, WA102, MARKIII, DM2 …

• Beijing Spectrometer (BES) J/ V f0; f0 PP, J/ f0; f0 PP, VV cj f0 f0, f0 f2 V=, , K*, ; PP=, , , KK^,

f0(1370) clearly seen in J/ , but not seen in J/ .

/J

/J

f0(1370)

NO f0(1370)

f0(1370) at BES

MeVMeVM

40265501350

S. Jin, Plenary talk at ICHEP04

f0(1370) is dominantover K K, , ; nonstrange nn*

• Clear f0(1710) peak in J/ KK.

• No f0(1710) observed in J/ !

f0(1710) at BES

KKJ /

/J

f0(1710)

NO f0(1710)

MeVMeVM

20125301740

CLKKfBR

fBR %95@13.0))1710(())1710((

0

0

S. Jin, Plenary talk at ICHEP04

f0(1710) KK^ is dominant. ss*

J/

c

c

uudd

J/

c

c

ss

= (uu+dd)/2 = ss

• A flavour filter for OZI singly disconnected transitions:

V=

f0(1370) f0(1710)

Could the exp. puzzle imply correlations between the structure of scalars and their prod. mechanism in J/ V f0 ?

gluec

c* M

J/

Glue rich intermediate statesf0

Lattice QCD prediction

Morningstar and Peardon, PRD60, 034509 (1999)

Glueball: Mesons are made of colored gluons confined by strong interaction

Lattice 0++: 1.5 ~ 1.7 GeVExp. Scalars: f0(1370)

f0(1500)f0(1710)f0(1790) (?) f0(1810) (?)

Mq

q*

q*

q

Glueball and QQ* mixing in the scalar mesons

In the basis of |G> = gg, |S> = ss*, and |N> = nn* = (uu*+dd*)/2, the glueball-quarkonia mixing can be expressed as:

S

N

G

Amsler & Close, PLB353, 385(1995); PRD53, 295(1996); Close & Kirk, PLB483, 345(2000).

where i=1,2,3, and f1,2,3 = f0(1710), f0(1500) and f0(1370), respectively.

Parameterization of f0 PP

g0 r2 g0 r3 g0

f0

P

P

Partial decay widths for f0 PP:

Close & Zhao, PRD71, 094022(2005)

S

N

G

Lattice QCD: MG ~ 1.5 – 1.7 GeV

f0 states

1710

1370

1500

WA102 WA102+BES

Strong QCD character.

Implications of the OZI-rule violation:

i) OZI rule on f0(1370): br(J/ f0(1370)KK^)<< br(J/ f0(1370)) Exp: br(J/ f0(1370)) is dominant !

ii) OZI rule on f0(1710): br(J/ f0(1710)KK^) > br(J/ f0(1710)KK^) Exp: br(J/ f0(1710)KK^) / br(J/ f0(1710)KK^) ~ 0.3 !

KK^

gg ss* nn*

0.36 0.93 0.09

0.84 0.35 0.41

0.40 0.07 0.91

c

c

ssf0(1710)

Scalar mesons production in J/ V f0

c

c*

(ss*)

f0 (ss*)

c

c*

J/ J/

(ss*)

f0 (nn*)

I) Singly disconnected diagram II) Doubly disconnected diagram

III) Glue configuration

c

c*

J/

(ss*)

f0 (gg)

pQCD Okubo-Zweig-Iizuka (OZI) rule: I) ~III) ~ II) =g2/4 ~ 0.3

However, a glueball component implies significant OZI-rule violations.

g g

J/

V (, )

f0

P

P

Factorization of J/ V f0 V P P

Transition amplitudes via potential V

III)I)II) Doubly OZI disconnected

Project to the final physical states:

Gluon-counting rule: I) ~ III)

Partial decay width for J/ V f0 V P P

c

c*

J/

(ss*)

G(gg)

c

c*

J/

(nn*)

G(gg)

Flavor-blindness of quark-gluon interaction:

Step 1: Direct test of the OZI rule

a) OZI rule applies: r 0

b) OZI rule violated: r ~ 1

r = 2.2

where

PDG estimate: Rexp = 0.75

BES Experiment: br(J/ f0(1710)KK*) = (2.0 0.7) 104

br(J/ f0(1710)KK*) = (13.2 2.6) 104

Step 2: Normalize the G production

Normalized glueball production b.r. ratios

Scalar decay br. ratios

Step 3: Theoretical predictions for J/V f0 V KK*, V

The “puzzle” can be explained in the glueball-QQ* mixing scheme, which implies large OZI violation effects in the scalar production.

Puzzle Evidence for the presence of scalar glueball ?

Further test of the gluon-QQ*mixings

i) f0 probe the quark components of

the scalars: f0(1370) : f0(1500) : f0(1710) ~

12 : 2 : 1

ii) f0 V, (V= , 0) f0(1710) ( ) > ( 0) f0(1370) ( ) < ( 0) f0(1500) ( ) < ( 0)

iii) J/ f0 f0(1710) > f0(1500) > f0(1370)

iv) c0f0f0, f0f2

0.36 0.93 0.09

0.84 0.35 0.41

0.40 0.07 0.91

gg ss* nn*

f0(1710)

f0(1500)

f0(1370)

+ + + + +

gg ss* nn*

f0(1710)

f0(1500)

f0(1370)

1 billion J/ events from BESIII

2. c0,2 hadronic decays VV, PP, & SS

(a) (b)

g0: basic gqq* coupling

r: OZI-rule violationR: SU(3)f breakingt: glueball coupling strength

g0

r

(c) (d)

Zhao, PRD72, 074001 (2005)

For a typical state:

the transition amplitude is factorized to be:

A commonly used form factor:

i) c0,2 V V

c0

c2

BES data

Predictions

The OZI violation need to be constrained by data for channel.

ii) c0,2 P P

Improved data for channel are required.

Exp. Data from BES for c0 f0(1710) f0(1370) KK. (hep-ex/0508050)

normalized

Branching ratio fractions

a) If OZI-rule is respected, i.e. r0,

will be the smallest decay channel.

b) If OZI-rule is violated, i.e. r1, will be the largest

decay channel.

iii) c0,2 f0 f0

Summary-1

I. The glueball contents are essentially important for interpreting the “puzzling” data from BES for the scalar meson production in J/ decays.

II. The strong glueball-QQ* mixings within the scalar mesons imply large OZI violations in J/ V f0, and suggest the crucial role played by the doubly disconnected processes.

A possible source for the OZI-rule violation is transitions via intermediate meson exchanges.

Zhao, Zou & Ma, PLB631, 22(2005), hep-ph/0508088.

K*

K

K

III. A normalization of the glueball production rate is obtained, which possesses predictive power for the study of the glueball mixing effects in the J/ radiative decay channel and c0 f0f0.

Further experimental data will be useful for establishing these f0 states as glueball-QQ* mixing states:

BES, CLEO-c, GSI (?)…Glue-X at JLab?

Summary-2

Thanks !

top related