"The High Statistic Study of Exotic Strange Multibaryon States in Subsystems with -Hyperons and K0

s Mesons at PANDA

P. Aslanyan

21-25 November, 2011, ITEP, Moscow

Introduction Study of in-medium effects of hadronic

particles Study of baryon spectroscopy with primary

and secondary targets Study of Hyper-nucleus with secondary target

Summary

Overview

Strange multibaryon states with - hyperon and K0s meson subsystems has been

studied by using of data from 700000 stereo photographs or 106 inelastic interactions which was obtained from expose 2-m propane bubble chamber LHEP, JINR by proton beams at 10 GeV/c. The observed well-known resonances 0, 0(1385) and K-(892) from PDG are good tests of this method. The according of PANDA(FAIR) program for primary and secondary targets can divide for the obtained results from PBC on three subjects of research, what are following. 1)Study of in-medium effects of hadrons.2)Study of baryon spectroscopy.3)Study of Hyper-nucleus with secondary target .At present the experimental situation is confused; so is theory. In the recent paper over viewing the status of the problem A. Gal wrote: “It is clear that the issue of K0 nuclear states is far yet from being experimentally resolved and more dedicated, systematic searches are necessary”. A survey for new experiments with much improved statistics(more than 10 times compared to those early data would hopefully resolve whether such "exotic“ multi-quark hadron and baryon resonances exist. The PANDA detector has a unique possibility for high statistic and with 4 geometry study above mentioned states with pC and -C collisions in the most interesting and a poor study energy .

Introduction

Physics - Nucleon StructureGeneralized Parton DistributionsTime-like Form Factor of the Proton

Physics - Hadrons in MatterThe study of medium modications of hadrons embedded in hadronic matter is aimed at understanding the origin of hadron masses in the context of spontaneous chiral symmetry breaking in QCD and its partial restoration in a hadronic environment. Another study which can be carried out in PANDA is the measurement of J/ψ and D meson production cross sections in p annihilation on a series of nuclear targets.

Physics - HypernucleiHowever, only 6 double Λ-hypernuclei are presently known, in spite of a considerable experimental effort during the last 10 years. A new chapter of strange nuclear physics will be opened whose first result will be the determination of the ΛΛ strong interaction strength, not feasible with direct scattering experiments.

Physics - Hadron Spectroscopy Charmonium Spectroscopy D Meson Spectroscopy Baryon Spectroscopy

PANDA at FAIR

There are observed fluctuations by momentum in ranges of 1.56(4), 1.9(3.5) and 2.15(3) GeV/c.

There are observed fluctuations (3) by ( ) angles in ranges of -0.70 and -6.8o (preliminary)..

The GEOFIT based on the GRIND-CERN program is used to measure of the kinematic parameters for tracks: total momentum(p), tg( is - depth angle ) and azimuthal angle() from the stereo photographs.

Study of in-medium effects of hadronic particles: the production of Hyperons

Spherical Coordinates System

The azimuthal () angle with geometrical weights for

The azimuthal angle is an angle measured from the x-axis in the xy-plane in spherical coordinates, The scattering () and azimuthal () angles without geometrical weights.

The comparison of FRTIIOF and experimental data shown that there are enhancement production for hyperons in ranges of < 0 and 0 angles.

The FRTIIOF model and experimental data comparison by the momenta of - shown that there is observed shift of distribution maximum from 200 MeV/c (FRITIOF)to 100 MeV/c for p+C-X reaction.

The spectrum without weights of and ; The spectrum for 2904 combination with bin size of 12 MeV/c2. The observed width of 0 is more than 2 times larger by total weight than value of experimental errors. There are also enhancements in mass ranges of 1290-1320 ,1360, 1420 and 1560 MeV/c2 which are can be reflection for enhanement productions from well known hyperons in effective mass spectrum from decay channel 0. After cut of total w< 16 Fig has shown small enhancements in mass ranges of 1300,1385 and 1560 MeV/c2

= exp - 1.61

Study of in-medium effects of hadronic particles: the production of K0s mesons

The comparison of FRTIIOF and experimental data shown that there is observed shift maximum for momentum distribution from 400 MeV/c (FRTIOF) to 900 MeV/c.

The comparison of FRTIIOF experimental data shown that there are enhancement production for K0

s mesons in ranges of < 0 and 0 angles. The FRTIIOF model and experimental data comparison by the momenta of - shown that there is observed shift of distribution maximum from 300 MeV/c(FRITIOF) to 100 MeV/c for p+CK0

s-X reaction.

Professor Marius UngarishDepartment of Computer ScienceTechnion, Israel Institute of TechnologyHaifa, IsraelE-mail: unga@cs.technion.ac.il

Abstract: A gravity current appears when fluid of one density, ρc, propagates into another fluid of a different density, ρα, and the motion is mainly in the horizontal direction. A gravity current is formed when we open the door of a heated house and cold air from outside flows over the floor into the less dense warm air inside. A gravity current is formed when we pour honey on a pancake and we let it spread out on its own. A gravity current which propagates inside a stratified fluid (rather than along a boundary) is called “intrusion.” Gravity currents (intrusions) originate in many natural and industrial circumstances and are present in the atmosphere, lakes and oceans as winds, cold or warm streams or currents, polluted discharges, volcanic ash clouds, etc. The efficient understanding and prediction of this phenomenon is important in numerous industrial, geophysical, and environmental circumstances. Simple qualitative consideration and observations indicate that the gravity current is a very complex, multi-faced, and parameter-rich physical manifestation. Nevertheless, the gravity current also turns out to be a modeling-friendly phenomenon. Indeed, visualizations of the real flow field reveal an extremely complicated three-dimensional motion, with an irregular interface, billows, mixing, and instabilities. The accurate numerical simulation of this flow from the full set of governing equations (the Navier-Stokes system) requires weeks of number-crunching on powerful computer arrays. On the other hand, there are “mathematical models” for the gravity current, whose derivation is based on a long line of assumptions such as hydrostatic pressure, sharp interface, Boussinesq system, thin layer, idealized release conditions. This simplified set of equations enables us to determine the behavior of the averaged variables entirely from analytical considerations and/or numerical solutions that require insignificant CPU time. The lecture gives a brief presentation of some typical models and solutions.

The background have done by polynomial, FRITIOF(left Fig.) and the open angles mixing(right Fig.) methods.

BARYON SPECTROSCOPY: p spectrum with stopped protons

p spectrum

19

STAR Au+Au coll. 200 GeV preliminary

Seen in 2 decay channels. The Sigma-K+channel tags the strangeness content as ssbar --> N0 candidate (Graal)

Consistent with a partial wave analysis of old data suggesting two narrow N states at 1680 and/or 1730 MeV width < 30 MeV (nucl-th/0312126, R Arndt et al)

S/(B)=5.15S. Kabana et al, hep-ex/0406032

S Kouznetsov et al, Graal, Trento,

Feb 2004

1727 MeV

1750+-18MeV

hep-ex/0504026, P Aslanyan et al

1734+-0.5 MeV

(K0s)spectrum at 10 GeV beam,

JINR

1st International Workshop on Soft Physics in Ultrarelativistic Heavy Ion Collisions (SPHIC06)

Decay mode M (MeV/c2) (MeV/c2) S.D.

0 55(PDG) 12.0

+ *+(1382) 40(PDG) 12.9

+-

*(1600) 55(PDG) 5.5

*(1750) 54(PDG) 4.2

*(1830) 51(PDG) 5.6

- *-(1370) 93 (PDG) 11.3

- (1320) - 3.0

*- (1480) - 3.2

p 2100 24 5.7

2150 19 5.7

2220 28 6.1

2310(2270) 30 3.7

2380 32 3.5

2370 - 4.5

pp 3140 40 6.1

3320 - 4.8

K0s 1750 14 5.6

1795 26 3.3

Table 1. The observed signals from mass spectra with subsystems

BARYON SPECTROSCOPY: K0sp spectrum with identified protons

04/21/23

Doubly Strange Systems at PandaF. Iazzi – Politecnico di Torino and INFN Sez. Di Torino

•Beam-target interaction•Expected - rates

Production of Doubly Strange Systems

Antiproton beam and internal target

Overview

• - hyper-atoms• - hypernuclei • hypernuclei

• Direct and indirect production with kaons, ions and antiprotons

• Two-target technique in PANDA

Physics of Double Strangeness

STRANGENESS IN NUCLEIF. Iazzi INFN-Torino&Politecnico

Production of S=2 Systems

Therefore the experimental determination of U is decisively important in order to obtain a reasonable inter action model. Here, we briey show the calculation results in three different interaction models; Nijmegen Hard-Core model D (NHC-D) Ehime model Extended Soft-Core model 04d (ESC04d)[20]These models give attractive (negative) value of U.

9Be(K-,K+) at E906• Two scenarios:

9 10 * Stopping & Fusion: Be Li

8 * 8 *( , ) direct capture & nucleon kickout or p K K He H

114 MeV/c 133 MeV/c104 MeV/c

The missing mass spectra(3428 comb.) for p+ p (-K0s)X reaction with bin

size of 40 MeV/c2. The curve is the sum of the background (by polynomial method 9-order 2/45=88 ) and 2 Breit-Wigner resonance (2/45=56). There is enhancement In the mass range of 3.355 MeV/c2 and 3.00 3H (2991) with exp 90 MeV/c2 ,SD >4.7(>90 events in peak) and with 4.5 (40-50 ev.)

The missing mass spectra for C( p,K0s)

There is not observed signal in missing mass spectra for p+ppK0sX in left Fig.. In

right Fig. there are small enhancements(3) for p+cpK0sX with identified

protons over Pp<1 GeV/c in mass range of K(500), f0(1020), (1780), M(2050) and M(2580). The dashed histogram is simulation by FRITIOF model.

The missing mass spectra(11118 comb. for p+3HpK0s X reaction with bin size of 40

MeV/c2. The curve is the sum of the background (by polynomial method 9-order 2/60=137 ) and 1 Breit-Wigner resonance (2/60=126). There is enhancement In the mass range of 6He(5.78 MeV/c2), with exp 90 MeV/c2 ,SD 5.7(>120-150 events in peak).

There is not observed signal in missing mass spectra for p(p,+) (up Fig. ) with 22149 comb.. There is not observed signals. The dashed histogram is simulation by FRITIOF model.

There is signal in missing mass range of 4

2He(3728)(65 events, 3.5) for p(p,) K+.There is not observed signals in missing mass spectra for C(p,K+).

Fig. has shown the missing mass spectrum of p(p,)- for 7219 events with bin size of 29 and 40 MeV/c2. There is obseved signals in mass range of 2580 MeV/c2 (4.2, 70 events)

The missing mass spectrum of p+p X reaction with - events and with bin size of 27 and 40 MeV/c2 for 5659 events. The curve is the sum of the background (by polynomial method 9-order2/109=270 ) and 1 Breit-Wigner resonance (2/109=164). There is enhancement in the mass range of M(3200) MeV/c2), with >90 MeV/c2 ,SD >6(120 events in peak). There is small peak in mass range of 3

H(3050) MeV/c2 as in in missing mass spectrum for all events from p+p X The dashed histogram is simulation by FRITIOF model.

Type of reaction Mass(GeV/c2) S.D.

p(p,K0s) 3.73(4He) 3.5

p(p,K0s-) 3.35

3.00(3H)

>4.74.7

P(p,K0sp)

P(p,K0sp)(p<1GeV/c)

2.580.5(Ks

0)1.022.050

3,23.1-.--.--.-

3H(p,Ks0p) 5.78(6He) 5.7

p(p,) 3.05 2.20

4.03.8

P(p,)K+ 3.73(4He) 3.5

p(p,)- 2.58 4.2

p(p,)- 3.20 4.2

Preliminary results

Next step is event by event analysis with KINFIT.

1 F= -3.590759E-02 2 F= 9.027166E-01 3 F= 1.746667E-01 4 F= 3.146067E-01 CHI2 = 1.287799E-01 PROB. = 7.197005E-01, p+12C12

B +K0s+p or p+ 6He 6

He + K0s+p T899(1) k37

1 F= -7.255827E-01 2 F= 1.121440 3 F= -5.837970E-01 4 F= 4.333572E-01 CHI2 = 6.758759E-03 PROB. = 9.344784E-01 p+ 3H 6

He + K0s+p T912(1)K819

mom.(GeV/c) tg Beam 9.423178 -.004545 1.651857K0 1.750026 -.251970 1.863762 6He (5.78) .00000 .000000 .000000

p 4.115269 -.052577 1.650334--------------------------------------------------------Pr. 0.750936 .364844 1.232637K0 2.161969 .209121 1.740758

Two prong star with two K0s

Three prong star with K0s

mom. (GeV/c) tg Beam 9.4871 -.01139 1.68008K0 .66519 -.56858 2.39480 12

B(11.356) .010 .12915 4.75202 p 7.98022 .00594 1.64052-------------------------------------------------P 1.18799 .25261 1.65367- .28522 -.04798 1.82060

Preliminary

S=-2 H-Dihyperon mass (Predictions)

spectrum from 2m PBC

Fig. has shown that there is significant enhancement in mass range of 2370(4.5S.D.) Mev/c2 for spectrum (201 combination). There are negligble enhancement in mass range of 2250, 2570 and 3100 Mev/c2 too.

S=-2 H0 and H+ dihyperons by weak decay channel s searches

Fig. has shown the event as candidates for heavy neutral H0→Λπ−p dihyperon in the decay length 21 cm from mother star and with mass of MH=2625(Meff.= 2626) MeV/c2(C.L.=96%) from kinematical fits. The reaction n-p has a kinematical fit (C.L.-22%) . Thus, the second V0 identified only by weak decay of the Λ hyperon at momentum PΛ = 794 MeV/c, which is directed to neutral two-prong star with effective mass Mπp =1836.25 MeV/c2which is also directed to primary mother interaction(four-prong-star) at beam momentum 10 GeV/c. There is fit with 2=10.8 (C.L. 0.1%) for reaction H0n→Λπ−p n with MH=2225 MeV/c2 too. Three events identified by this topology

The projectile secondary negative relativistic track at momentum of P-=1.1 GeV/c, 8.2 cm long, is formed by the beam proton, what is emitted from four prong star. After break of the second part of track is identified as thick solid track, which can registered by relative ionization as 3H in length 2.73 cm and a momentum of 0.870 GeV/c. This track is induced of second vertex . The V0 is identified as a weak decay of a K0

s meson at omentum 0.471 GeV/c , with 6.3 cm length. The emitted negative track from the second vertex is identified as - at momentum of 0.353 MeV/c. Fig~a)has shown - C

3H+(or -) + K0s, K0-

+,3H(or ) 3He(n) + - multi-vertex reaction as candidate for hypernuclear 3H where we can clear see all stages of multivertex event.

Photography for 3H and dihyperons identified by weak decay channel

Experimental Challenges with High Statistic in Strangeness Nuclear Physics. The 4 geometry detector and high resolution measurements are necessary. Low energy pions (50-200 MeV/c) and protons(100-200 MeV/c) registration are necessary. The experimental data shown that detector acceptance is necessary to cover of angles < 0 ( ~ 11 deg.) and 0 for K0

s and production .

Establishment of truly exotic hadrons dihyperons K(bar) bound states YN scattering experiments -hypernuclei Expand the world of hypernuclei Multi-hypernuclei We have opportunities! J-PARC, BNL, Jlab, Dane, LEPS, FAIR, IHEP, JINR.

Nature is more rich and beautiful than we can imagine!

Thank You!

Summary