Strange Pentaquarks

Michał PraszałowiczM. Smoluchowski Inst. of Physics

Jegellonian University, Kraków, Poland

Strange Pentaquarks

Michał PraszałowiczM. Smoluchowski Inst. of Physics

Jegellonian University, Kraków, Poland

~1540

9.12.2008 Michal Praszalowicz, Krakow 5

Time dependent experimental status of Q+

γ + d (n ) 　 reactions

γ + p → p Ks0 　

γ + p → n K+ K- +

K + (N) → p Ks0

lepton + D, A → p Ks0

p + A → pKs0 + X

p + p → pKs0 + S+

Other Q+ Upper Limits

BaBar

CLAS-d2

BELLE

ALEPH, Z SVD2

LEPS-d2LEPS-C CLAS-d1

DIANA

SAPHIR

SVD2

COSY-TOF

HermesJINR

CLAS-p

LEPS-d

nBCZEUS

BES J,Y

CLAS g11

SPHINXHyperCP

HERA-BFOCUS WA89CDF

: Positive result

: Negative result

2002 2003 2004 2005 2006 2007

DIANA

COSY-TOF

6

Ideal experiment

7

Formation cross sectionBreit-Wigner cross-section (GM + MP)

0 1/2

1/2

1/2 1/2

K+

n

7.12.200 Michal Praszalowicz, Krakow 8

Time dependent experimental status of Q+

γ + d (n ) 　 reactions

γ + p → p Ks0 　

γ + p → n K+ K- +

K + (N) → p Ks0

lepton + D, A → p Ks0

p + A → pKs0 + X

p + p → pKs0 + S+

Other Q+ Upper Limits

BaBar

CLAS-d2

BELLE

ALEPH, Z SVD2

LEPS-d2LEPS-C CLAS-d1

DIANA

SAPHIR

SVD2

COSY-TOF

HermesJINR

CLAS-p

LEPS-d

nBCZEUS

BES J,Y

CLAS g11

SPHINXHyperCP

HERA-BFOCUS WA89CDF

: Positive result

: Negative result

2002 2003 2004 2005 2006 2007

DIANA

COSY-TOF

10

BELLE: secondary kaon beamfrom D decays interactingwith silicon in vertex detecor :

< 0.64 MeVR. Mizuk, Europhysics 2005, Lisbon. July 2005

11

12

Time dependent experimental status of Q+

γ + d (n ) 　 reactions

γ + p → p Ks0 　

γ + p → n K+ K- +

K + (N) → p Ks0

lepton + D, A → p Ks0

p + A → pKs0 + X

p + p → pKs0 + S+

Other Q+ Upper Limits

BaBar

CLAS-d2

BELLE

ALEPH, Z SVD2

LEPS-d2LEPS-C CLAS-d1

DIANA

SAPHIR

SVD2

COSY-TOF

HermesJINR

CLAS-p

LEPS-d

nBCZEUS

BES J,Y

CLAS g11

SPHINXHyperCP

HERA-BFOCUS WA89CDF

: Positive result

: Negative result

2002 2003 2004 2005 2006 2007

DIANA

COSY-TOF

positive result from LEPS (Japan) remains

13

T. Nakano (Osaka)

Evidence of the Theta+ in the gamma d ---> K+ K- pn reaction.By LEPS Collaboration (T. Nakano et al.). Published in Phys.Rev.C79:025210,2009. e-Print: arXiv:0812.1035

7.12.2008 Michal Praszalowicz, Krakow 14

15

MMgK- (GeV)

T. Hotta, Acta Phys. Pol. B36, 2173

7.12.200 Michal Praszalowicz, Krakow 16

Time dependent experimental status of Q+

γ + d (n ) 　 reactions

γ + p → p Ks0 　

γ + p → n K+ K- +

K + (N) → p Ks0

lepton + D, A → p Ks0

p + A → pKs0 + X

p + p → pKs0 + S+

Other Q+ Upper Limits

BaBar

CLAS-d2

BELLE

ALEPH, Z SVD2

LEPS-d2LEPS-C CLAS-d1

DIANA

SAPHIR

SVD2

COSY-TOF

HermesJINR

CLAS-p

LEPS-d

nBCZEUS

BES J,Y

CLAS g11

SPHINXHyperCP

HERA-BFOCUS WA89CDF

: Positive result

: Negative result

2002 2003 2004 2005 2006 2007

DIANA

COSY-TOF

X

negative results from CLAS high statistics d runcontradicts previous CLAS analysisand contradicts LEPS

Comparison of LEPS and CLAS

7.12.2008 Michal Praszalowicz, Krakow 17

Comparison of LEPS and CLAS

7.12.2008 Michal Praszalowicz, Krakow 18

7.12.200 Michal Praszalowicz, Krakow 19

Time dependent experimental status of Q+

γ + d (n ) 　 reactions

γ + p → p Ks0 　

γ + p → n K+ K- +

K + (N) → p Ks0

lepton + D, A → p Ks0

p + A → pKs0 + X

p + p → pKs0 + S+

Other Q+ Upper Limits

BaBar

CLAS-d2

BELLE

ALEPH, Z SVD2

LEPS-d2LEPS-C CLAS-d1

DIANA

SAPHIR

SVD2

COSY-TOF

HermesJINR

CLAS-p

LEPS-d

nBCZEUS

BES J,Y

CLAS g11

SPHINXHyperCP

HERA-BFOCUS WA89CDF

: Positive result

: Negative result

2002 2003 2004 2005 2006 2007

DIANA

COSY-TOF

XX

negative results from CLAS high statistics runcontradiced previous experiments

7.12.2008 Michal Praszalowicz, Krakow 20

t-channel production of Q+

p Q+K*

K0

n Q+K*+

K-

p Q+K0

K0

n Q+K+

K-

7.12.2008 Michal Praszalowicz, Krakow 21

t-channel production of Q+

p Q+K*

K0

n Q+K*+

K-

p Q+K0

K0

n Q+K+

K-

known

? ?

7.12.2008 Michal Praszalowicz, Krakow 22

CLAS estimate

limits correspondingto the rangeof K* couplings

Main assumption

7.12.2008 Michal Praszalowicz, Krakow 23

Theta+ exists with M ~ 1540 MeVand total width ~ 1 MeV

What about other members of antidecuplet?

9.12.2008 Michal Praszalowicz, Krakow 24

NA 49NA 61

~1540

1861 ?

1647 ?

1754 ?

9.12.2008 Michal Praszalowicz, Krakow 25

~1540

7.12.2008 Michal Praszalowicz, Krakow 26

hn measurement in D(g,hn)p Kunznetsov et al. preprint (05)

hn hp

GRAAL:hn measurement: quasi-free kinematics

Is there a narrow resonance in nucleon excitation?

eta photoproduction on nucleon

Michal Praszalowicz, Krakow 27

8 10

N

S

Q

28

•Hints from PWA (Arndt, Azimov, Polyakov, Workman)• STAR (Kabana....)

Properties of N*(1685)

Michal Praszalowicz, Krakow 29

η photoprodution depends on: Br x μtransition2

and is therefore dependent on model calculation of μtransition

Г > 1 MeV

Decay to pionis suppressed

Very

goo

d ca

ndid

ate

for

nucl

eon-

like

mem

ber o

fan

tidec

uple

t

Decay widths

SU(3) relations

= reduced matrix element × SU(3) Clebsch

Decays of N*(1685) in SU(3) limit

Michal Praszalowicz, Krakow 31

Problem: in SU(3) limit decay to pion is 3 times larger than to eta

Solution: mixing

SU(3) flavor symmetry

N

,S

-

N ,S, ,

Some trivial facts on SU(3) breaking

Exact SU(3)

N

,S

-

N ,S, ,

N

S

Broken SU(3)

all masses equal GMO mass formulae

SU(3) flavor symmetry

N

,S

-

N ,S, ,

Some trivial facts on SU(3) breaking

Exact SU(3)

N

,S

-

N ,S, ,

N

S

Broken SU(3)

all masses equal GMO mass formulae

Mixing8 10

N

S

Q

mixing with ground state octet αthe same for N and Σ

Decay of Theta+

8 10

N

S

Q

Θ+ → K N

Decay of Theta+

Θ+ → K N Normal situation: large small large

Antidecuplet: small small large

CA

NC

ELLATIO

N !

Chiral Quark Soliton Model

In large Nc non-relativistic limit:

Low lying J+ baryon multiplets

Mixing with „Roper ocet”8 10

N

S

Q

mixing with „Roper octet” φthe same for N and Σ

„Roper octet”

1440****

1600 ***, 1660***

1690*** (spin=?,P=?)

N

,S

- GMO mass formula

works wellimprovement possiblethrough additional

mixing

Decays of N10(1685)mixing with the Roper octet

Constraining mixing angles

Decays of N10(1685)branching rats.along the orange line

Properties of Σ10 and Ξ10

Michal Praszalowicz, Krakow 46

dashed = GMO

Properties of Σ10 and Ξ10

Michal Praszalowicz, Krakow 47

NA 49 (1860) excluded

Michal Praszalowicz, Krakow 48

~1540

1861 ?

1647 ?

1754 ?

1685

~1815

~1935

Properties of Σ10

Michal Praszalowicz, Krakow 52

Properties of Ξ10

Michal Praszalowicz, Krakow 53

Summary

Michal Praszalowicz, Krakow 54

We still need a dedicated K+N formation experiment todecide existence of Theta+

If Theta+ exists and has total width ~ 1 MeV:

• new narrow resonance N(1685) can be interpreted as a member of antidecuplet only if mixing is included• we propose to consider mixing of antidecuplet with Roper and ground state octets (Roper does not decay to eta N)• SU(3) forbidden decay of N(1685) to πΔ is 20 – 65 %• fixing mixing angles from N(1685) we calculate masses and partial widths of antidecuplet Sigma M ~ 1815 MeV, decays: KN 60% and πΛ 20%, Г~10-30 MeV• antidecuplet Xi ~1935 (contradicts NA 49), Г~10 MeV