Photoproduction of Photoproduction of KK* * for the study of the structure ofor the study of the structure o

f f (1405)(1405)

Photoproduction of Photoproduction of KK* * for the study of the structure ofor the study of the structure o

f f (1405)(1405)

Tetsuo Hyodoa

a RCNP, Osaka b IFIC, Valencia c Barcelona Univ.

2003, November 4th

A. Hosakaa, E. Osetb, A. Ramosc and M. J. Vicente Vacasb

1. Introduction1. Motivation : Two poles?

2. Chiral unitary model1. Framework of the chiral unitary model2. Example : Kp scatterings3. Pole structure of (1405)4. Example : p -> K0

3. K*(1405) production1. Effective interactions2. Numerical results

ContentsContents

Motivations : Two poles?Motivations : Two poles?

• Cloudy bag model (1990) J. Fink et al. PRC41, 2720

• Chiral unitary model (2001~) J. A. Oller et al. PLB500, 263 E. Oset et al. PLB527, 99 D. Jido et al. PRC66, 025203 T. Hyodo et al. PRC68, 018201

There are two poles of the scattering amplitudearound nominal (1405) energy region.

(1405) : JP=1/2, I=0

ChU model, T. Hyodo

Chiral unitary modelChiral unitary model

Unitarity of S-matrixChiral symmetry

Flavor SU(3) meson-baryon scatterings (s-wave)

Resonances

Low energy behavior

Non-perturbativeresummation

(1405), (1670), N(1535),(1620), (1620)

Dynamicalgeneration

Chiral perturbation theory

Unitarization

Framework of the chiral unitary modelFramework of the chiral unitary model

Resonances

Generated resonances areexpressed as poles of the scattering amplitude.

Total cross sections of Kp scatteringsTotal cross sections of Kp scatterings

T. Hyodo, et al., Phys. Rev. C 68, 018201 (2003)

200

150

100

50

0300200100

K-p

70

60

50

40

30

20

10

0300200100

0

200

150

100

50

0300200100

+−

60

50

40

30

20

10

0300200100

Plab [ / ]MeV c

K0n

60

50

40

30

20

10

0300200100

Plab [ / ]MeV c

0080

60

40

20

0300200100

Plab [ / ]MeV c

−+

(1405) in the chiral unitary model(1405) in the chiral unitary model

D. Jido, et al., Nucl. Phys. A 723, 205 (2003)

mass distribution

1390 + 66i (

1426 + 16i (KN)

Example : the p -> K0 reactionExample : the p -> K0 reaction

Chiralterm

N(1710)

Chiral unitary model

Results for p -> K0Results for p -> K0

T. Hyodo, et al., nucl-th/0307005, Phys. Rev. C, in press

Total cross sections [mb]Mass distribution

� There are two mechanisms in the initial stage interaction, which filter each one of the resonances.

Good agreement(1385) effect

Photoproduction of K* (1405)Photoproduction of K* (1405)

Only Kp channel appears at the initial stage

Higher pole ??

Effective interactions for meson partEffective interactions for meson part

1. VP coupling

2. VPP coupling

Effective interaction for (1385)Effective interaction for (1385)

3. (1385)MB coupling

4. KP -> (1385) -> MB amplitude

SU(6) symmetry

2.5x10-3

2.0

1.5

1.0

0.5

0.01550150014501400135013001250

MI [ ]MeV

00 (~ =0)I average of charged 0 ( =1)I

Experiments : mass distributionExperiments : mass distribution

Plab = 2.5 GeV/csqrt s ~ 2.35 GeV

Preliminary

Summary and conclusionsSummary and conclusions

We study the structure of (1405) using the chiral unitary model.

� There are two poles of the scattering amplitude around nominal (1405).

Pole 1 (1426+16i) : strongly couples to KN statePole 2 (1390+66i) : strongly couples to state

http://www.rcnp.osaka-u.ac.jp/~hyodo/index_e.html

� By observing the mass distribution in the p -> K*(1405) reaction, it could be possible to isolate higher energy pole.

Appendix : other processesAppendix : other processes

p -> K

p -> J.C. Nacher, et al., PLB461, 299(1999)

J.C. Nacher, et al., PLB445, 55(1999)

Spring-8

J-PARC?