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Hadron Structure 2011.

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E-mail: afanasev@lhe.jinr.ru

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  1. Hadron Structure 2011 S.V. Afanasiev,1 A.S. Artiomov,1 R.N. Bekmirzaev2, D.K. Dryablov,1 Z.A. Igamkulov,1 V.I. Ivanov,1 A.Yu. Isupov,1 D.M. Jomurodov,1 A.I. Malakhov,1 V.Matousek3, M.Morhac3 A.I. Lebedev,4 A.I. L’vov,4 L.N. Pavlyuchenko,4 E.B. Plekhanov1, V.V. Polyansky,4 S.S. Sidorin,4 G.A. Sokol4, M.U. Sultanov5, I.Turzo3"Search Results for Eta-Mesic Nuclei in the d+C Reaction in JINR" E-mail: afanasev@lhe.jinr.ru LHEP JINR Dubna afanasev@lhe.jinr.ru TatranskáŠtrba, June 30th

  2. Hadron Structure 2011 Motivation • The properties of hadrons in nuclear medium are one of the interesting topics of the modern hadron and nuclear physics. All nuclei have essentially smaller mass than sum of masses all neutrons and the protons formed nuclei. The difference of masses is a result of strong interaction between hadrons which formed composite system. It is possible to assume, that particles, distinct from nucleons such as an  - meson, in nuclear medium will have smaller mass than in a free state. Physical aims • a new field in studies on nuclear and particle physics. • new data on the -meson and the S11(1535) resonance interactions with nucleons • determination of the energy levels E_g (S11) and E_g() and their widths g(S11) and g() in the -nucleus • determine mass shift m(S11) and m() in the nuclear medium • A possibility to perform studies on physics of - mesic nuclei at the JINR nuclotron internal beam reaction p+An+p+ (A - 1) or d+An+p+n+ (A - 1) • elementary process p+n* n+S+11(1535)* n+ p + * • TatranskáŠtrba, June 30th afanasev@lhe.jinr.ru

  3. Hadron Structure 2011 • K. Tsushima , D.H. Lu , A.W. Thomas, K. Saito Physics Letters B 443 1998 26–32, • “Are - and -nuclear states bound.” K. Tsushima Nuclear Physics A670 (2000) 198c-201 c ,“Study o f , , ' and D--mesic nuclei” • A. I. L'VOV nucl-th/9809054 • PRODUCTION AND DECAY OF ETA • -MESIC NUCLEI • Proposed mass shift for S11 • m(S11) = (24÷30)η + (8)N =30-40 MeV • In nuclear medium • TatranskáŠtrba, June 30th afanasev@moonhe.jinr.ru

  4. Hadron Structure 2011 Photoproduction of mesons from nuclei - In-medium properties of hadrons B. Krusche, nucl-ex/0411033 Formation of an η mesic nucleus and its decay via emission of back-to-back nucleon-pion pairs. • TatranskáŠtrba, June 30th afanasev@moonhe.jinr.ru

  5. Hadron Structure 2011 Formation, evolution an decay 0.9 • Proposed formation in NN interaction p+Ap+n+ (A - 1) (13C- prefer ) n+An+p+ (A - 1) • Investigate d+A1A2(S11)  +p+... • Evolution in the elementary process S11(1535)* N +  • Decay to the -N, N-N and  - channels 0.1 L.C.Liu Phys. Rev. C 40 p.832 Scheme of the resonance formation In the elemental NN interaction produced  or  mesons at 180o. N(1535)S11 I(JP)=1/2 ( 1/2- ) L(,) =0 Mass m=1520 to 1550 (1535) MeV Full width =100 to 250 (150) MeV 10-5 afanasev@lhe.jinr.ru • TatranskáŠtrba, June 30th

  6. Hadron Structure 2011 Bounding energy p+A d+ p=0+(A-1)p=0 d+A t+ p=0 +(A-1)p=0 Pp = Pd Pd = Pt Et = 6.25MeV Ed = 2.22MeV 13C +d= 12C+t+Q Q=1.3 MeV 1) -meson production 2) To produce stable nucleus-rest from target 3) Effective capture of the meson 4) To measure the products of decay • TatranskáŠtrba, June 30th afanasev@lhe.jinr.ru

  7. Hadron Structure 2011 Kinematic of recoil-free transfer reaction 13C(p,d)12C 13C(d,t)12C • TatranskáŠtrba, June 30th afanasev@lhe.jinr.ru

  8. Hadron Structure 2011 Estimates of the effect yield Y(p, -)= L (p12Cp1p2n(A-1))  Br(N)     nc f(p/)  - total cross section of eta-nuclei formation; L - luminosity;  - the solid angle;  - the probability to have the p pair f(p/) - a geometric fraction; Br(N) -the branching ratio of S11(1535) decay; nc - accelerator cycles per hour; Production of -mesons in nucleon-nucleon collisions V. Baru, PHYSICAL REVIEW C 67, 024002 (2003) Y(p)  1400 events Y(pp)  230 events Y(pp)  250 events Y(ppp)  40 events Y(pnp)  35 events Y(pnpp)  6 events • TatranskáŠtrba, June 30th afanasev@lhe.jinr.ru

  9. Hadron Structure 2011 Experimental setup K-arm K1 - Start counter K2 - Trigger & Cherenkov counters K3 - TOF - wall K4 - E-counter K5 - Veto counter P-arm P1 - Start counter P2 - Trigger & Cherenkov counters P3 - TOF - wall P4 - E-counter P5 - Veto counter Hm - Ring counter N - Neutron detector An - Neutron-Veto FL,FR,BL,BR - Monitors • TatranskáŠtrba, June 30th afanasev@lhe.jinr.ru

  10. Hadron Structure 2011 Construction of the Internal Target Station Dimension of the target region Target -1 -- 12C, 8 wires x 8 mkm Target -2 -- 27Al, 1 mm strip x 10 mkm Target -3 - - 64Cu, 8 wire x 50 mkm Target -4 - - 183W, 1 wire x 20 mkm Target -5 -- 108Ag, 1 mm strip x 20 mkm Target -6 -- CH2, 1 mm strip x 10 mkm PMT for light control • TatranskáŠtrba, June 30th afanasev@lhe.jinr.ru

  11. Hadron Structure 2011 Setup of the experimental RUN The geometry of the experiment K-arm P-arm • TatranskáŠtrba, June 30th afanasev@lhe.jinr.ru

  12. Hadron Structure 2011 Reconstracted mass(confidence level > 95%) Effectivemass TOF0.2 ns M5MeV/c2 • TatranskáŠtrba, June 30th afanasev@lhe.jinr.ru

  13. Hadron Structure 2011 Effective mass formation in dA reaction at the energy 1.5 GeV/nuc Counts/10MeV/c2 The distributions of the N pair yields are shown in Fig.(a,b) versus Meff of the pair nucleons. The histogram Fig.(b) shows the contamination obtained at the arm angle 170o.The Fig.(a) corresponds to a back-to-back correlation coming from the two-body decay. The histogram Fig.(c) is the result of subtraction the back-to-back (180o) and the contamination measurements. The ratio of the nucleon pair numbers was N{170}/N{180}=0.42 + 0.08(stat) in the mass region of 1450 < Meff< 1550 MeV/c2. New data are collected. They are include 105 pairs coming from target in d+Cu and d+C reactions at the energy of primary beam 1.5GeV/nuc and 1.9Gev/nuc. (a) (b) (c) • TatranskáŠtrba, June 30th afanasev@lhe.jinr.ru

  14. Hadron Structure 2011 Y(,p)1.41.8 GeV/c2 Effective mass formation in dC reaction at the energy 1.9 GeV/nuc The yield of proton-pion pairs: p1700 p1800 afanasev@lhe.jinr.ru • TatranskáŠtrba, June 30th

  15. Hadron Structure 2011 New data 2010 Y(,p)2.0 GeV/c2 Effective mass formation in dC reaction at the energy 2.0 GeV/nuc Best fit is Gaussian + constant Mean 1465.1 MeV Sigma 27.2 MeV Constant 1310 1800 Total events under picks ≈2000 • N(1535)S11 I(JP)=1/2 ( 1/2- ) L(,) =0 • Mass m=1520 to 1550 (1535) MeV • Full width =100 to 250 (150) MeV ΔM≈70 MeV Δ • S11 Distribution after rejection of the constant level S11 In medium • TatranskáŠtrba, June 30th afanasev@lhe.jinr.ru

  16. Hadron Structure 2011 The value of the total cross-section of the process can be found based on the number of inelastic interactions dC, measured on the accounts of monitor telescopes, and the simulation results using the software package GEANT and RQMD. Inelastic interaction Nin = 1.5÷2.2*109; Solid angle: Ω = 8 10-3 str. Cross-section of dC inelastic interactions at the energy 2.1GeV/nuc.: σin=426 ±22 mb Total cross-section is : μb Newest data 2010 give the similar result for p-π pars • TatranskáŠtrba, June 30th afanasev@lhe.jinr.ru

  17. Hadron Structure 2011 Conclusions • Have been measured the energy-sum and the angular correlation of two nucleon pairs p emitted in the d+C reaction. Ithave been clearly observed a distinct p back-to-back correlation coming from a target, which may be associated with the signature of two-body final state. • Data analyses are shown resonance structure formed in the target at the energy region of primary beam 1.5-2.0 GeV/nucl. • The resonance is shifted to small masses an shift has value around 70 MeV and width of the rsonance is 63 MeV. It disagree theoretical predictions. • The value of the total cross-section is estimated 10b. • TatranskáŠtrba, June 30th afanasev@lhe.jinr.ru

  18. Hadron Structure 2011 New proposal for η–nuclear study on nuclotron. • d+A1A2(S11)  -+p+... • d+A1A2(S11)  ++n+... • d+A1A2(η+d*)  p +n+... η+d p +n • TatranskáŠtrba, June 30th afanasev@lhe.jinr.ru

  19. Hadron Structure 2011 • Collaboration • S.V. Afanasiev, A.S. Artiomov, D.K. Dryablov, Z.A. Igamkulov, V.I. Ivanov, A.Yu. Isupov, A.I. Malakhov,1 E.B. Plekhanov • Joint Institute for Nuclear Research, 141980 Dubna, Moscow Region, Russia • V.Matousek, M.Morhac, I.Turzo • Institute of Physics, Slovak Academy of Sciences, Slovak republic • S. VokálJ. Vrláková, A. Kravčáková, A. Dirner, M. Špavorová,   • Faculty of Science, University of P.J. Šafárik, Košice, Slovak republic • A.I. Lebedev, A.I. L’vov, L.N. Pavlyuchenko, V.V. Polyansky, S.S. Sidorin, G.A. Sokol, • Lebedev Physical Institute, Leninsky Prosect 53, Moscow 117924, Russia • D.M. Jomurodov, R.N. Bekmirzaev, • Jizzakh State Pedagogical Institute, Uzbekistan • M.U. Sultanov, • Samarkand State University, Uzbekistan • TatranskáŠtrba, June 30th afanasev@lhe.jinr.ru

  20. Hadron Structure 2011 Thank you for attention! • TatranskáŠtrba, June 30th afanasev@lhe.jinr.ru

  21. Hadron Structure 2011 The SCAN spectrometer can register only tail of Δ-resonance. Momentum of protons is limited Pp>230 МэВ/с. • TatranskáŠtrba, June 30th afanasev@lhe.jinr.ru

  22. Hadron Structure 2011 Numerical calculation d+A t+ p=0 +(A-1)p=0 p+A d+ p=0+(A-1)p=0 d+A 3He+ p=0 +(A-1)p=0 (p) (p) (3He) • TatranskáŠtrba, June 30th afanasev@lhe.jinr.ru

  23. Hadron Structure 2011 • TatranskáŠtrba, June 30th afanasev@lhe.jinr.ru

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