H-dibaryon properties from a QCD sum rule approach with diquark effective

fields

Kyungil KimNovember 15th , 2012, Busan, `ATHIC 2012’

Based on K. Kim, D. Jido, S.H.Lee PRC 84(2011)025204 K. Kim, D. Jido, S.H.Lee in preparation.

Motivation : Diquarks

1/15Nov. 15th 2012

Quark Correlations in QCD Confinement Chiral symmetry breaking Color triplet correlation between quarks

Phenomenological Evidence of Diquark Baryon spectroscopy Deep inelastic scattering Quark condensation in dense matter

lim𝑥→ 1

𝐹2𝑒𝑛

𝐹 2𝑒𝑝=

14

qqq

qq

q q

Motivation : Diquark Structures in HadronsSHLee and S.Yasui : EPJ C (2009)

<Diquark inside baryons>

<Quark-antiquark inside mesons>

2/15Nov. 15th 2012

Diquark Structures and Heavy-quark

<Tetraquark> qq

h h

<H Dibaryon>

<Pentaquark>

ud

h us

ud

su

ds

3/15

N*, Θcs, …

<Baryon>q

hq Λ, Ξ, …

Nov. 15th 2012

Λ Baryons

u d

h

<Current for Λ >

Scalar diquark fieldGauge invariant Lagrangian for diquark field

4/15

<Color-spin interaction>

Nov. 15th 2012

uh- and dh-interaction are cancelled by each other.

Effective Diquark FieldsGauge invariant Lagrangian for diquark field

The relation between diquark condensate and gluon condensate

5/15

<Propagator of diquark field>

Nov. 15th 2012

Single gluon with momentum

Two gluons at one vertex

λ : parameter for condensate

mΦ : diquark mass

QCDSR with Di-quark fieldsOPE Result (up to dim. 6)

6/15Nov. 15th 2012

Λ BaryonsDiquark Mass (GeV) Ratio(λ)

0.2 -0.50.3 -0.20.4 -0.013

0.41 0

Parameter Set ( ms=0.12GeV, mΛ =1.115GeV)

7/15Nov. 15th 2012

Λ Baryons

<Lambda_c sum rule> <Lambda_b sum rule>

8/15Nov. 15th 2012

Diqaurk Masses from Various Approaches

9/15Nov. 15th 2012

<QCD sum rule>

<Lattice QCD> <Bethe-Salpeter equation>

ref/Jamin PLB238(1990)387The mass difference be-tween ud- and qs-diquark is ~200MeV.

ref/Hess PRD 58,111502

ref/Cahill PRD 36,2804

Ξ Baryons

<Ξ_c sum rule> <Ξ_b sum rule>

10/15Nov. 15th 2012

H-dibaryon

11/15

<Theoretical Prediction of H-dibaryon> <Lattice QCD results>

<HAL collaboration>

<H-dibaryon search in STAR at RHIC>

Nov. 15th 2012

H-dibaryon

12/15

ud

su

ds

u ds

ud s

<Current choice for H-dibaryon>

<Dispersion relation>∼ Spectral Density

Nov. 15th 2012

OPE Result (up to Dim. 4)

13/15Nov. 15th 2012

Results in SU(3)(flavor) Sym.

<Borel Curves with various threshold>

14/15Nov. 15th 2012

Summary & Outlook

15/15

The QCD sum rule approach with diquark fields gives a good result for Λs, Ξs and H-dibaryon.

We can have a diquark mass and condensate values from Lambda.

These parameters give good masses for Lambda_c and Lambda_b.

In same approach, we can obtain the properties of ‘qs’-di-quark from Ξ_c.

We obtain the mass of H-dibaryon from a QCD sum rule ap-proach with effective diquark fields.

Pentaquarks(N*,Θcs) and tetraquarks(T_cc, T_cb) are also good candidates to apply this approach. (in progress)

Nov. 15th 2012

Thank you very much!!