Study of K - p→ Lp + p - , Lp 0 and γn → K + Σ* -

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Study of K Study of K p→ p→ , , and γn → K and γn → K + + Σ* Σ* JiaJun WU JiaJun WU IHEP IHEP In collaboration with Pu Ze Gao, S. Dulat, B. S. ZOU and A. Sibirtsev

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Study of K - p→ Lp + p - , Lp 0 and γn → K + Σ* -. JiaJun WU IHEP. In collaboration with Pu Ze Gao, S. Dulat, B. S. ZOU and A. Sibirtsev. Outline. Introduction The research of K - p→ Lp + p - The research of γn → K + Σ* - The research of K - p→ Lp 0 Summary. Introduction. - PowerPoint PPT Presentation

Transcript of Study of K - p→ Lp + p - , Lp 0 and γn → K + Σ* -

Page 1: Study of K - p→ Lp + p - ,  Lp 0  and  γn  → K + Σ* -

Study of KStudy of Kp→p→,, and γn and γn → K→ K++Σ*Σ*

JiaJun WU JiaJun WU IHEPIHEP

In collaboration with Pu Ze Gao, S. Dulat, B. S. ZOU and A. Sibirtsev

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OutlineOutline

IntroductionIntroductionThe research of KThe research of Kp→p→

The research of γn → KThe research of γn → K++Σ*Σ* The research of KThe research of Kp→ p→ SummarySummary

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IntroductionIntroduction resonances in PDG

(1189)1/2+ *(1385)3/2+*(1670)3/2-

*(1775)5/2-*(1915)5/2+ *(2030)7/2+

These information are all from 1970-1985. The data are very OLD!!

****

****(1660)1/2+*(1750)1/2-

*(1940)3/2-*(2250)??*(1620)1/2- *(1690)??*(1880)1/2+*(2080)3/2*(2455)?? *(2620)??

***(1480)?? *(1560)??*(1580)3/2-

*(1770)1/2*(1840)3/2+ *(2000)3/2-

*(2070)5/2+ *(2100)7/2- *(3000)??*(3170)??

*

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IntroductionIntroductionExperimental:

The limited data and knowledge of background

Large uncertainties for both established and unestablished *.

New resonances have not been discovered.

Theoretical:There are many new models for baryon compared to the 30 years ago : penta-quark models and meson cloud models

u /d asymmetry in the proton

The mass order reverse problem between N*(1535) and *(1405)

The Large strange components in N*(1535)

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The prediction of 5-quark model

* [us][ds]s ~ 1575 MeV

* [us][du]d ~ 1360 MeV

* [us][ds]u ~ 1520 MeV

Capstick 3q model

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IntroductionIntroduction We should re-examine old data, to find some new We should re-examine old data, to find some new

information about information about *.*.

Fortunately, there are 3 new experiments for Fortunately, there are 3 new experiments for *.*.

K p

*n K

CLAS 2005: *0p K

LEPS 2009:

E=1.5-4 GeV

E=1.5-2.4 GeV

2009:Crystal Ball

T. S. Mast, and R. D. Tripp et al. PRD 7, 5 (1973). Pk=0.3—0.6GeV

D. O. Huwe, Phys. Rev. 181, 1824 (1969). Pk=1.0—1.8GeV

0K p Pk=514-750 MeV

We use Effective Lagrange method to analysis these reactions.

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Research of KResearch of Kp→p→

Pk=1.0-1.8 GeV

1 2

2 2 2 2 21 ( )

ni

i i i i

dNp p

dm

a

m m m

p1 is module of 3-momentum of in the C.M..

p2 is module of 3-momentum of in the rest system of *.

D. O. Huwe, Phys. Rev. 181, 1824 (1969).

93% *(3/2+)+7% background

ndf=10.1 / 9)

58% *(3/2)+ 37% *(1/2)+ 5% background

(2/ndf=3.2 / 9)

J. J. Wu, S. Dulat and B. S. ZouPRD 80, 017503 (2009)

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Pk=0.3-0.6 GeV

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100% *(3/2+)

Phase space

First reason: S-wave between the *3/2+) and but P-wave between the *(1/2) and .

Second reason: the width of *3/2+) is 35.5MeV; but that of *(1/2) is 118.6MeV from fit before.

J. J. Wu, S. Dulat and B. S. Zou PRC 81,045210

59% *(3/2)+ 41% *(1/2)59% *(3/2+)

12.5% *(1/2-)

Interference

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γn → Kγn → K++Σ*Σ*

*0p K

//

• Total cross section of CLAS well described.

• differential cross section of LEPS data also be described, but not for the beam asymmetry Abeam .

*n K

Hicks, et.al. (LEPS), PRL102,012501(2009)

Two Methods to Solve this Problem.

//

//beamA

and denote the cross sections for beam polarization vertical and parallel to reaction plane, respectively.

K

K

*(3/2)*(1/2)

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K

a. Including

K

K

+

b. Tuning parameter h in contact term for

• h=1 for to describe the total cross section.

• Free h for without .

*0p K *n K

h is the parameters of contact term

Puze Gao, J. J. Wu, B. S. Zou, PRC81:055203

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Include

h=1.11

ddcosc.mfor n K compared with LEPS data

h=1.0

*0p K

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KKp→ p→

Crystal Ball 2009: 0K p pK=514-750 MeVPrakhov et al., PRC 80,025204

The 4-star resonances as follows are always included

With only t-, u- and the above 4 s-channels, the best fit of 17 parameters gives =763 for the 248 data points, including

(1189)1/2+ *(1385)3/2+*(1670)3/2-*(1775)5/2-

*(1915)5/2+ *(2030)7/2+

Differential cross

sections

polarization

is the angle of 0 and K- in the C.M. frame.

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with inclusion of (1660)1/2+, =223 for 248 data points with 21 free parameters.

Best results with (1660)1/2+, fitted parameters for resonances

KKp→ p→ 00

Puze Gao, B.S. Zou, A. Sibirtsev arXiv:1011.2387 [nucl-th]

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For (1380)1/2-, the present data is insensitive to it, and it is neither supported nor excluded.

Differential cross sections

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SummarySummary

With the analysis of three reactions:With the analysis of three reactions:

K p→ ππΛK p→ ππΛ

γn → KΣ*γn → KΣ*

K p→πΛK p→πΛ

The evidence of *(1/2-) predicted by the penta-quark models.

Existence of (1660)1/2 +(***), with mass near 1635MeV, width 121MeV.

Need More experiment data to confirm them!!

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Thank you!Thank you!