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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