1. Programme Advisory Committee for Nuclear Physics 28th meeting, 19-20 June 2008 RECOMMENDATIONS WALTER GREINER

2. Preamble The Chairperson of the PAC, Walter Greiner, welcomed the PAC members, in particular the new members C. Beck, V. Ostashko, O. Zimmer, the expert Z. Vilakazi, the ex-officio members from JINR, and presented the implementation of the recommendations taken at the previous meeting. JINR Vice-Director M. Itkis informed the PAC about the Resolution of the 103rd session of the Scientific Council (February 2008) and about the decisions of the Committee of Plenipotentiaries (March 2008). The PAC was pleased to learn about the visit to JINR, on 18 April 2008, of the President of the Russian Federation, D. Medvedev. Together with leaders of government agencies and regions of the host country, the President was presented with information on the research work of the Flerov Laboratory of Nuclear Reactions, in particular on the discovery of superheavy elements, and on other areas of the Institute ’ s activity.

3. 3 Status and prospects of investigations on the theme “Synthesis of New Nuclei and Study of Nuclear Properties and Heavy-Ion Reaction Mechanisms” The PAC discussed in detail the status and mentioned trends of possible investigations within the theme “Synthesis of New Nuclei and Study of Nuclear Properties and Heavy-Ion Reaction Mechanisms”, presented in the report by FLNR Scientific Leader Yu. Oganessian. The PAC endorses the activity of the FLNR, in line with the previous recommendations of the PAC, aimed at modernizing the cyclotrons and extending the experimental potential of the Laboratory. However, taking into account the need of a new perspective of studies of both neutron-rich light nuclei and superheavy nuclei, the PAC invites the Laboratory to work out a long-range programme of further developments of the accelerator complex and of state-of-the-art experimental facilities of the next generation.

4. The main purpose is the quantitative increase of the efficiency of experiments as a whole by at least one order of magnitude to allow the Laboratory to keep its leadership during the next decades.

5. neutrons protons 50 82 28 50 28 20 8 8 2 2 126 H. Jensen, E.P. Wigner and M. Goeppert-Mayer Nobel prize 1963 Nuclear shells Heaviest nuclei Exotic area Lightest nuclear ? Yu. Oganessian. Heavy Ion Physics in JINR. 28-th PAC meeting, June 19-20, JINR, Dubna

7. no shell effect was observed evidence of shell structure strong shell effect in the “doubly-magic” nucleus unbound S 2n = -1.07 MeV A.N. Ostrowski et al., HMI 1994 S 2n = -1.2 MeV A.A. Korsheninnikov et al., RIKEN 1994 S 2n = -3.0 MeV G.M. Ter-Akopian et al., FLNR 2008 discovery “di-neutron” in halo-nucleus 6 He FLNR 2001

8. “Blanc spot” on the Nuclear Chart blanc spot fragmentation (spallation) fusion

9. New theoretical concepts require more detailed data on the structure of neutron and proton rich nuclei. Further development of the DRIBs complex will allow one to carry out these investigations much more efficiently.

10. On the way to the first Island of Stability “cold” fusion reactions: 208 Pb + 64 Ni, 70 Zn, … → 272 110, 278 112, … “hot” synthesis: 238 U, 244 Pu, 248 Cm, 249 Cf + 48 Ca → 286 112, 292 114, 296 116, 297 118

12. 242 Pu, 245 Cm 244 Pu, 248 Cm 237 Np 243 Am 249 Cf Decay chains Decay chains 34 nuclides 85 decay chains was registered 48 Ca + FLNR 2000-2006

13. Reported at DGFRS: Oganessian et al. 2004 283 112 9.37 MeV 287 114 279 Ds  : 0.592 s SF 108+123 MeV Observed in Chemistry: 11.05.2006 283 112 9.48 MeV 287 114 279 Ds  : 0.536 s SF 127+105 MeV 25.05.2006 Result from the 48 Ca + 242 Pu experiment 283 112 4 s 9.54 MeV 287 114 0.51 s 10.02 MeV 279 Ds 0.18 s SF(>90%) 205 MeV 283 112 9.52 MeV 287 114 279 Ds  : 0.072 s SF 94+51 MeV 10.04.2007 283 112 9.52 MeV 287 114 279 Ds  : 0.088 s SF 112(sgl) MeV 13.04.2007

14. 5.04.2007 Result from the 48 Ca + 242 Pu experiment 287 114 Deposition Temp.: -72 °C 283 112 10.9 s 9.53 MeV 287 114 10.04 MeV 279 Ds 0.24 s SF 103+114 283 112 4.0 s 9.54 MeV 287 114 0.51 s 10.02 MeV 279 Ds 0.18 s SF DGFRS Observed in chemistry

16. Recommendation: The PAC strongly recommends to start a detailed consideration of a long-term plan for the development of the FLNR accelerator complex and experimental facilities. It should be presented at the next PAC meeting.

17. Recommendations on the themes previously approved for completion in 2008

18. Nuclear Theory The PAC took note of the report on the closing theme “Nuclear Theory” (01-3-1029-99/2008) and the proposal for a theme “Nuclear Structure and Dynamics”. The PAC highly appreciates the results obtained in the main research directions: nuclear structure far from the stability valley, nucleus-nucleus collisions at low energies, few-body systems, nuclear dynamics at relativistic energies, properties of hot and dense nuclear matter. The PAC also appreciates the educational activities of BLTP and relations of theoretical studies to the JINR experimental programme. The PAC supports the continuation of nuclear theory activities under a new theme that should incorporate a complex and broad view on the various aspects of nuclear structure and dynamics.

19. Nuclear Theory Project Leader 1. Nuclear structure V.V. Voronov far from stability valley A.I. Vdovin J. Kvasil 2. Nucleus-nucleus collisions R.V. Jolos and nuclear properties N.V.Antonenko at the low energies

20. Nuclear Theory Project Leader 3. Exotic few-body systems A.K.Motovilov V.B.Belyaev 4. Nuclear structure and V.V. Burov dynamics at the relativistic S.N.Ershov energies M.Gaidarov

21. Continuum spectroscopy of two-neutron halo nuclei S.N. Ershov, B.V. Danilin, J.S. Vaagen ( Phys. Rev. C74 (2006) 014603 ) L.V. Chulkov et al., Nucl. Phys. A759, 23 (2005) ■ nn C x y nn x C y Theoretical analysis of various angular and energy correlations of the three fragments in 6 He breakup on 208 Pb at collision energy 240 MeV / nucleon have been performed. The analysis has been based on a microscopic four-body distorted wave approach to breakup reactions and uses the three-body model for the nuclear structure of the two-neutron Borromean halo nucleus 6 He. → n 1 + n 2 + 4 He + A’ 6 He + A → n 1 + n 2 + 4 He + A’ The kinematically complete breakup reaction Correlations between fragments in different Jacobi coordinate systems

22. Microscopic theoretical analysis of the 6 He+p elastic and 6 He+ 28 Si reaction cross sections The microscopic optical potential was constructed and applied to analyse the experimental data of FLNR JINR and the other centers. We tested the three current models of 6 He+p: Tanihata's, COSMA (M.Zhukov et al) and LSSM (S.Karataglidis et al). Total reaction cross- section without collective excitation included Total reaction cross- section with collective excitation included The model density distributions LSSM

23. Recommendation. The PAC recommends approval of the new theme "Nuclear Structure and Dynamics" for the years 2009–2013 with first priority.

24. Educational Programme The PAC took note of the report on the theme “Organization, Maintenance, and Development of a University-Type Education Process” (06-0-1026-98/2008). The PAC supports the proposal by the UC Director concerning the increase of the budget required to complete the creation of student laboratories and to enlarge the number of PhD students. Today you heard report D. Fursaev. I leave comment of education programme. Recommendation. The PAC recommends extension of this theme for the years 2009–2013 with first priority. A detailed educational programme including the list of lectures, lecturers and time table should be presented at the next PAC meeting. The possibility for licensing the status of the PhD students, especially for the Member States, should be examined.

25. IREN The PAC took note of the report on the theme “Construction of the IREN facility” (03-4-0993-94/2008). The PAC highly appreciates the efforts of the JINR Directorate and the laboratories involved in the implementation of this project. The plans to start up the facility at the end of 2008 seem to be realistic. The PAC also appreciates the efforts of the FLNP Nuclear Physics Department on preparation of the experimental infrastructure at IREN Phase I. V. Shvetsov had talk about IREN yesterday. Recommendation. The PAC recommends that the theme “Construction of the IREN facility” be finished in 2008, and the financial resources for the maintenance, operation and development of the IREN facility be kept within the theme “Nuclear Physics with Neutrons –– Fundamental and Applied Investigations”.

26. First experiment at IREN-1: measurement of capture cross section for 181 Ta: demonstration experiment Experimental program: cross section measurements for nuclear engineering and nuclear astrophysics (n,p), (n,  ) reactions nuclear structure studies: search for vibrational resonances in stable nuclei search for subthreshold p-resonance in Pb search for PT-violation in neutron-nucleus interactions neutron activation analysis isotope production

27. A number of preliminary experiments which are valuable themselves should be performed at IREN facility: 1. Study of resonance spectra of promising isotopes: energies, widths, spins, parities and p 1/2 -p 3/2 channel mixing of neutron resonances. 2. Gamma-spectra of the resonances which are promising for the discussed purposes, linear polarization of the lines of interest. 3. P-violation effects in γ -transitions induced by neutrons of the resonance energy. IREN is capable to measure P-violation effect up to 10 -3 for an intensive gamma-line. The versions of the approach aimed to search for PT-invariance break up seem to be a way to reduce upper limit of the PT-invariance break up effect achieved recently in nuclear experiments by several orders of magnitude and approximate it to the level of accuracy attained in permanent EDM measurements for isovector PT-noninvariant amplitude. SEARCH FOR PT-INVARIANCE BREAK UP

28. Recommendation The PAC recommends concentrating available human, financial and technical resources of the FLNP Nuclear Physics Department mainly on the realization of the proposed scientific programme for IREN-1 and on the development and preparation of the programme for the full-scale IREN facility.

29. Poster session The PAC was particularly pleased with the presentations of new results and proposals by 13 young scientists in the field of nuclear physics research. This type of presentations should be continued in future.

30. Scientific reports The PAC heard with interest the report “Reactions with exotic nuclei at FLNR”, presented by V. Zagrebaev. The experiments discussed in the report are strongly connected with the realization of the DRIBs programme, in particular its application to studies of astrophysical importance, also with the use of beams heavier than 6 He. The PAC heard with interest the scientific report, presented by V. Belyaev, on the application of few-body methods to the calculation of triple processes in astrophysics. In particular, his evaluation of K-capture in p+ 7 Be process demonstrates the importance of the method for the exact calculation of the solar neutrino flux.

31. Next meeting of the PAC The next meeting of the PAC for Nuclear Physics will be held on 22–23 January 2009. Its tentative agenda will include: Reports and recommendations on the themes and projects to be completed in 2009 Consideration of new projects Research programme at the LEPTA facility Status of the EDELWEISS experiment Poster presentations of new results and proposals by young scientists in the field of nuclear physics research Scientific reports.

32. Thank you very much for your attention

33. Low-energy multi-nucleon transfer (Zagrebaev & Greiner, Phys. Rev. Letters, 2008 )