1. Contents
Preview
The PBC Method
- hyperons and K0S-mesons production
(+) spectra
(-) spectra
(+-) spectra
(p) spectra
(p p) spectra
(p -) spectra
( ) spectra
( ,K0 s,)spectra
(K0s,  )spectra
conclusion
Review for exotic strange multibaryon state searches with -hyperon systems in p+A collisions at momentum 10 Gev/c
P.Zh.Aslanyan . JOINT INSTITUTE FOR NUCLEAR RESEARCH,
YEREVAN STATE OF UNIVERSITY .

2. Preview
There are a few actual problems of nuclear and particle physics which are concerning subject of this report. These are following goals: in-medium modification of hadrons, the origin of hadron masses, the restoration of chiral symmetry, the confinement of quarks in hadrons, the structure of neutron stars . Multi-quark states, glueballs and hybrids have been searched for experimentally for a very long time, but none is established. Strange multi-baryonic clusters are an exiting possibility to explore the properties of cold dense baryonic matter and non-perturbative QCD.
Strange multibaryon states with - hyperon and Ks0 –meson systems has been identified by using data from stereo photographs or 106 inelastic experimental events which is obtained on 2-m propane bubble chamber JINR exposed proton beams at 10 GeV/c. A survey for new experiments with much improved statistics compared to those early data would hopefully resolve whether such "exotic“ multi-quark hadron and baryon resonances exist. There are not sufficient experimental data concerning for strange-hyperons production in hadron -nucleus and nucleus-nucleus collisions over momentum range of GeV/c.

3. The PBC method
A reliable identification of the above mentioned resonances needs to use 4-detectors and high precision measurements of the sought objects. The bubble chamber is the most suitable instrument for this purpose . The full experimental information of more than stereo photographs or 106 events from p+propane inelastic interactions are used to select the events with V0 strange particles . The GEOFIT based on the Grind-CERN program is used to measure the kinematics parameter of tracks momenta(P), tg( - depth angle) and azimuthal angle() in the photographs. The momentum resolution and the average track length L of charged particles are found to be P/P=2.1%,< L>=12 cm for stopped particles and P/P>=9.8 %, <L>= 36 cm for nonstopped particles. The mean values of measurement errors for the depth and azimuthal angles are equal to tg = ± and  = ± (rad.).
The estimation of ionization, the peculiarities of the end track points of the stopped particles(protons, K ) allowed one to identify them. Protons can be identified over the following momentum range: 0.150 P  GeV/c. In the momentum range P > GeV/c protons couldn't be separated from other particles.

4. - hyperons and K0S-mesons production
Proc.International Conference on LOW ENERGY ANTIPROTON PHYSICS ,May 16-22, Bonn - Julich, Germany, 2005; AIP,v. 796, p.195, ISBN ,Melville, NY. hep-ex/ ,2005..P.Z. Aslanian ,The XIth International Conference on EDS-05, May 16-20, Blois, France, XVIII Baldin ISHEPP, Dubna,September 25-30, Spin’06, October 2-7, Kyoto, Japan Proc. IUTP07, Schladming, Austria, February 26, "Particles and Nuclei, Letters“, Vol. 4, No. 1,pp , 2007.
Figures (a,c) and (b,d) show the effective mass distribution of 8657-events with , 4122-events with Ks0 particles and their 2 from kinematical fits, respectively. The expected functional form for 2 is depicted with the dotted histogram. The measured masses of these events have the following Gaussian distribution parameters MK= 497.7± 3.6, s.d.= 23.9 MeV/c2 and M  = ± 0.6, s.d.=10.0 MeV/c2. The masses of the observed , Ks0 are consistent with their PDG values. Measured experimental inclusve cross sections are equal to 13.3 and 4.6 mb for  and Ks0 production in the p+C collisions at 10 GeV/c.

5. / + - ratio
Strange particles have been obtained extensively inhadron–nucleus and nucleus–nucleus collisions in 4–15 GeV regions [1–6].
The experimental data from heavy ion collisions show that the K + /+ ratio is larger at BNL-AGS energies than at the highest CERN-SPS energies and even at RHIC[9-14]. This behavior is of particular interest as it could signal the appearance of new dynamics for strangeness production in high energy collisions.
The number of -s produced in antiproton +Ta reaction at 4 GeV/c was 11.3 times larger than that expected from the geometrical cross section (KEK, Japan) [9].
Therefore, the analysis of strange hyperon and K+ total yields [12–14] are of great interest as an indicator of strange quark production. Figure shows the energy dependence of the  /+, - / + and the - / +. As can be seen from the figure there is a very clearly pronounced maximum especially in the  / + ratio.
The multiplicity of  and + production in C+C reaction at 10 GeV/c have been used the Glauber approach based on the experimental cross section for p+C  X from this experiment [14]. The  /+ ratio from this experiment in pC reaction is approximately two times larger than ratios at the same energies for pp reaction and for same reaction, which was simulated by FRITIOF model.
Figure : Prediction of the statistical-thermal model[5,6] for  /+ note the factor 5, solid line ), and -/+ (dashed line) and ­/ + ratios a function of s. For compilation of AGS data see [7]. The  /  + ratio in interaction C+C was obtained by using data from this experiment for pC  X .
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hep-ph/ ,2001.
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[8] M. Gazdzicki, hep-ph/ v2,2003.
[9] K. Miyano et al., Phys. Rev. C38 (1988).
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[11] S. Albergo,et. al.,Phys. Rev. Lett. 88,v.6, 2002.
[12] B. Back et al.,E866, E917 Collab., nucl-ex/
[13]J. C. Dunlop and C. A. Ogilvie, Phys. REV. C, VOLUME 61,031901(R),2000;
[14] P.Z. Aslanian et. al., JINR comm., E , 2005.
"Particles and Nuclei, Letters".

6. (+ ) spectra
Test method with known resonance. The resonance with similar decay properties *(1382) registered. Decay width is equal to  40 MeV/c2 (M/M0.7 %). A masses and width consistent with PDG values for *(1382). The cross section of *(1382) production (540 simulated events) can estimated by FRITIOF model which is equal to 1.0 mb (540 simulated events) at 10 GeV/c for p+C interaction.

7. Preliminary results for (- ) spectra
The - effective mass distribution for all combinations with bin sizes of 18 and 12 MeV/c2. The solid curve(Fig.a) is the sum of the background (by the first method ) and 1 Breit-Wigner resonance. There is significant enhancement In the mass range of 1372 MeV/c2, with S.D.= 11.3, =93 MeV/c2. The cross section of *-(1385) production (680 events) is equal to  1.4 mb at 10 GeV/c for p+C interaction.
The width of -(1385) have observed 2 times larger than PDG value. Figure (b) shows effective mass distribution with scale of 12 MeV/c2, where there are also significant enhancements in mass regions of 1345(3.0 S.D.) and 1480(3.2 S.D.). There are negligible enhancements in mass regions of 1410, 1520 and 1600 MeV/c2.

8. Preliminary new results for (- ) spectra
The cross section of - production (60 events) stopped in nuclear medium is equal to  15 b at 10 GeV/c for p+propane interaction. Expected number events with - is equal 8 events(w=1/e =5.3).The observed experimental production of - is larger 7-8 times than the number of expected - events which is similarly simulated by fritiof model. There is observation for *-(1480) resonance too which is agreed with SVD2 result from ICHEP06.

10. Preliminary (,+,- ) spectrum
The +- effective mass distribution for all 3476 combinations with bin sizes 36 and 16 MeV/c2. The curves(Fig.) are the the background by the polynomial method.There is significant enhancement in mass region (1600)(4.0 S.D.)from PDG. There are small enhancements in mass regions of 1530 and 1690 MeV/c2 which are interpreted as a reflection from resonances (1520) and (1690) from PDG. There are not observed exotic states which were earlier observed and published for ++ spectrum (in mass ranges 1704,2071,2604 Mev/c2) by PBC method in neutron exposure.

11. (p) spectra
Preview
The first evidence for Quantum Chromodynamics (QCD), the theory of the strong interactions, came from the systematics of baryon and meson spectroscopy. Already back in 1977 Jaffe, using the bag model in which confined colored quarks and gluons interact as in perturbative QCD, suggested the existence of a light nonet composed of four quarks mesons, five quark baryons, six quarks dibaryons et.al..
A phenomenological model is proposed for the analysis of the properties of the Kaonic Nuclear Cluster (KNC) K−pp in its ground state. For the first time the KNC 2KH has been investigated by Akaishi and Yamazaki within the PotentialModel (PM) approach.
Very recently, possible existence of discrete nuclear bound states of Kp has been predicted based on the experimental information on the KN scattering lengths, kaonic hydrogen atom and the (1405) resonance. In this model the pp pair inside the KNC 2KH is in the 1S0 state and the K−p pairs are in the S –wave states. Thus, the p pair, produced in the reaction K−(pp)1S0 → p, is in the 3P0 state.

12. (,p) spectra in p+propane collision at 10 GeV/c
P.Z. Aslanyan et al., Proc. “I.Y. POMERANCHUK AND PHYSICS AT THE TURN OF CENTURIES Moscow, January 24–28, 2003.Proc.International Conference on LOW ENERGY ANTIPROTON PHYSICS ,May 16-22, Bonn - Julich, Germany, 2005; AIP,v. 796, p.195, ISBN ,Melville, NY. hep-ex/ ,2005..P.Z. Aslanian ,The XIth International Conference on Elastic and Diffractive Scattering, May 16-20, Blois, France, XVIII Baldin ISHEPP, Dubna, September 25-30, Spin’06, October 2-7, Kyoto, Japan Proc. IUTP-07,Schladming, Austria, February 26, 2007
The total experimental background has been obtained by three methods. In the first method, the experimental effective mass distribution was approximated by the polynomial function after cutting out the resonance ranges because this procedure has to provide the fit with 2=1 and polynomial coefficient with errors less than 10 %.
The second of the randomly mixing method of the angle between proton and  for experimental events is described in JINR Rapid Comm., N6(74),p209, Then, these background events were analyzed by using the same experimental condition and the effective mass distribution was fitted by the polynomial function. The analysis done by two methods has shown that while fitting these distributions had the same coefficients( with 30 % errors) and order of polynomial.
The third background method has been obtained by using FRITIOF model
with experimental canditions (FRITIOF, H. Pi, Comput. Phys.Commun. 71,173, 1992).
The values for the mean position of the peak and the width obtained by using Breit Wigner fits . The statistical significance for the fit on Fig. inside a mass window is calculated as NP /(NB)1/2, where NB is the number of counts in the background fit under the peak and NP is the number of counts in the peak.

14. .
The p effective mass distribution for combinations for identified protons with a momentum of 0.350 P  GeV/c is shown in Figure. The solid curve is the sum of the background by the first method and 4 Breit-Wigner resonances . There are significant enhancements in mass regions of 2100, 2180, and 2353 MeV/c2 (Table,Fig.). Their excess above background by the second method is 6.9, 4.9, 3.8 and 2.9 S.D., respectively. There is small peak in the mass region of MeV/c2. These peaks are agreed with experimental data from PBC in neutron exposure. The peaks are agreed with experimental data from FOPI,FINUDA and OBELIX collaboration which was recently obtained.
M, MeV/c2  , MeV/c2 S.D.

15. Talk of N. Hermann(FOPI), on BARYON07, Seul.

16. Preliminary result for (,p) spectrum with stopped protons
The p effective mass distribution for combinations for stopped protons with a momentum of 0.14 P  0.30 GeV/c. The momentum resolution for stopped protons is equal to p/p=1% . In this case we have good statistic and effective mass resolution M/M0.6%.

17. (,p) spectrum with stopped protons
Decay mode
Effective mass(Mev/c2)
Experimentalwidth(Mev/c2)
Width(Mev/c2) 
Statistical
significance p
2100 36 24
5.7
2150 32 19
2220 23
6.1
2310 44 30
3.7
2380 46
3.5
A significant peak at invariant mass M ~ 2220 MeV/c2 , BK ~ 120 MeV was specially stressed by Professor T. Yamazaki on CF2007, Dubna, June that is conform with KNC model prediction by channel of K-pp --> + p .

18. (,p,p) spectrum in p+propane collision at 10 GeV/c
The pp effective mass distribution for combinations for identified protons at a momentum of P <0.9 GeV/c is shown in Figure. The solid curve is the 6-order polynomial function( 2/n.d.f=245/58, Fig.a ). The backgrounds for analysis of the experimental data are based on FRITIOF and the polynomial method.
There is significant enhancement in mass region of 3138(6.1 S.D.) and with width 40 MeV/c2. There are small enhancements in mass regions of 3199(3.3 S.D.) and 3320(4.1 S.D)MeV/c2(2.6 S.D.). These peaks in ranges of 3138 and 3199MeV/c2 were agreed with registered peaks: from reports[3-4] of E471 experiment, PS,KEK, from experiments FOPI and OBELIX.
1. M. Iwasaki et al., Nucl. Instrum. Meth. A 473 (2001) Y. Akaishi and T. Yamazaki, Phys. Rev. C 65 (2002) T. Suzuki et al., Phys. Lett. B 597 (2004) M. Iwasaki et al., nucl-ex/ , submitted to Phys. Lett. B.

19. Talk by N. Hermann(FOPI), on BARYON07, Seul.

20. (,p,-) spectrum in p+propane collision at 10 GeV/c
The p- effective mass distribution for combinations for identified protons with a momentum of P <0.9 GeV/c is shown in Figure. The background (solid curve) is taken by the 6-order polynomial function which is satisfactory described the experimental data( 21, in Fig.). But the background by FRITIOF model do not describe the experimental distribution. The sum of BW (with mass 2460 MeV/c2 and experimental width 280 MeV/c2) and FRITIOF model for p- effective mass distribution is satisfactory described the experimental data too. Therefore one of probably Interpretation about this peak can be only reflection from phase space distribution too. Earlier published result about observation resonance with mass 2495 MeV/c2 and width 200 MeV/c2 for p spectrum by PBC method for neutron exposure(7 GeV/c) is not uniquely conformed.

21. ( ,p, ) spectra from neutron exposure on PBC

22. Preliminary (,  ) spectra in p+propane collision at 10 GeV/c
There is observed statistical enhancement in mass region of 2360(4.0 S.D.).
Mev/c2 .This peak is conformed earlier published result from neutron exposure by PBC method
with very small statistics too. There is small enhancement in mass range
of 2500 Mev/c2.

23. Ks0  - spectrum
( K 0s ) -spectra

24. Ks0  - spectra analysis, at 10 GeV/c on PBC
P.Z. Aslanyan et al., Proc.International Conference on LOW ENERGY ANTIPROTON PHYSICS ,May16-22, Bonn - Julich, Germany, 2005; AIP, 796,ISBN JINR comm., E , 2005.
"Particles and Nuclei, Letters“,v.3, N5(134),p.331, 2006.
The Ks0 effective mass distribution for combinations is shown in Figure. The solid curve is the sum of the background by the first method and Breit-Wigner resonances . Similar results have obtained when using a Breit Wigner distribution and different bin sizes. There are significant enhancement in mass region of MeV/c2 (5.6 S.D.) and with experimental width 32 MeV/c2 . The cross section is equal to 30 b for p+propane reaction.

25. These peaks are possible candidates for two pentaquark states: the N0 with quark content udsds decaying into K0 and the 0 quark content udssd decaying into ( K0 ), which are agreed: with the calculated rotational spectra N0 and 0 spectra from the theoretical report of D. Akers(arXiv.org:hep-ex/ , 2004) (below figure) and with + spectra from the experimental report of P. Aslanyan JINR, E ,2004 .

26. (K0s ,) spectra
Talks: XVIII Baldin ISHEPP, Dubna, September 25-30, Spin’06, October 2-7, Kyoto, Japan2006.
The scalar mesons have vacuum quantum numbers and are crucial for a full understanding of the symmetry breaking
mechanisms in QCD, and presumably also for confinement. Suggestions that the  (600) and (800) could be
glueballs have been made. There are theoretical arguments for why a light and broad (800)(qq or 4-quark state) pole can exist near the K threshold and many phenomenological papers support its existence . The (600) and (800) indeed belong to the same family as the f0(980) and a0(980) mesons (say if the  (600) were composed of 2 or 4 u and d type quarks) then no such mechanism would suppress the decay 0(600)+- or (800) K.
There is believe that experimental groups should look for pole positions in their data analysis, which also include the aforementioned nonlinear effects from S-wave thresholds. The E791 Collaboration reported a light  with mass 797 MeV and width 410 MeV, but uses a Breit–Wigner amplitude . This claim was, however, not confirmed by the CLEO Collaboration. A lighter and very broad  pole is nonetheless possible and should be looked for in future data analyzes. “
The total statistics for effective mass distribution of K0s+ from reactions p+propane has shown in Figure. The solid curve is the background taken in the form of a polynomial up to the 8-th degree. The dashed histogram is the background by FRTIOF. The invariant mass has significant enhancement in range of 890 Mev/c2(from PDG). There are peaks in mass ranges of 720(4.6), 800(4.2) and 1060(7.3) Mev/c2.

27. The solid curveis the sum of 2BW and background (black) taken in the form of a superposition of polynomial up to the 6-th degree. The dashed curve(red) is the background by polynomial without mass range of 0.75< MK <0.98 MeV/c2 when a 1BW function was used.

28. statistical significance
The solid curveis the sum of 2BW and background (black) taken in the form of a superposition polynomial up to the 6-th degree. The dashed curve (red) is the background by polynomial without mass range of 0.75< M K <0.96 MeV/c2 when was used 1BW function.
Resonance
decay mode
MK MeV/c2
Experimental
Width (e)
MeV/c2 
The
statistical significance
K0s
890 70 52
780 30 12
720
55-145
35-125

29. Conclusion
The invariant mass of + and K0s  spectra has observed well known resonances *+(1385) and K*( 892) ( from PDG). Test method.
A number of important peculiarities were observed in pA  (K0S ) X reactions in the effective mass spectrum for exotic states with decay modes: 1) ( , ), ( ,  ,), ( ,p), ( , p, p), ( , );
2) ( ,K0S), (K0S,  ).
Peaks for ( ,p) and ( , p, p) spectra are agreed with experimental data from the recently reports of FOPI, OBELIX, FINUDA collaborations, but there are inconstancy for widths.
The intriguing results of the observation on propane bubble chamber has induced the interest and to continue these searches for exotic states with  hyperon and K0s– meson systems at FAIR (GSI), JPARC(KEK), NICA(JINR), Frascati, CLOE,JLAB and other experiments, which will get a valuable information about their nature, properties and et.al. It will be a test for observed data on PBC. Higher statistics, the effective mass resolution about 1% and the analysis data from interactions by using different nucleus are needed.
Frascati, October 11, 2007