DEPARTMENT OF THEORETICAL PHYSICS 149

8.3 with Mean-field Instantons by J.Skalski

We consider [1] a variational search for instantons imposed on trial paths (momentum-velocity relations) - imaginary-time mean fields, describing spontaneous to provide an upper bound for the instanton action. A fission, and generally quantum tunneling, within the simple implementation of those conditions is mean-field theory. The specific nature of imaginary- necessary to make a variational approach feasible. time mean-field equations requires that each fission path consists of two, necessarily different, branches. [1] Proceedings of the Int. Workshop on "New For each mean-field state of one branch, there is an Developments in Nuclear Self-Consistent Mean- associated state of the second branch and together they Field Theories (MF05)", p. B62, Yukawa Institute serve as bra and ket in the calculation of observables. for Theoretical Physics reports series (2005): A formula for the decay exponent is given in terms (http://www.nucl.ph.tsukuba.ac.jp/MF05/proceedi of trial Hartree-Fock states. Though exact for an ngs.html) instanton, it requires additional conditions to be

8.4 6 Hiperons in Nuclear by J.Dą browski

Our work on the interaction of 6 hiperons with important in the description of 6 production reactions, nuclei was continued. We applied previously derived for 6 atoms, and also for the properties of expressions for the single particle potential V of the 6 stars. hiperon in nuclear matter [1] to investigate the dependence of V on the nuclear matter density and on [1] J.Dą browski, Phys. Rev. C 60 (1999) 025205 the 6 momentum. We obtained results [2] for V - in [2] J.Dą browski, Acta Phys. Pol. B 36 (2005) 3063 particular for the isospin and spin dependent parts of [3] J.Dą browski, J.RoĪ ynek, Acta Phys. Pol. B 37 V - for the Nijmegen models of the baryon-baryon (2006) 87 interaction. These results, discussed in [3], are

8.5 6 Atoms and Density Distributions by J.Dą browski

The analyses of measured cross sections for 6 information on these distributions, especially at the production reactions, of observed properties of 6 nuclear periphery. The procedure requires the atoms, and of the two-body hiperon-nucleon data knowledge of V for which we assume the Nijmegen indicate that the 6 N interaction V is well described by model F [1, 2]. model F of the Nijmegen baryon-baryon interaction. -- We have shown - on the example of the 6 208Pb [1] J.Dą browski, J.RoĪ ynek, Eur. Phys. J. A 25 atom - that we may exploit the sensitivity of the (2005)137 calculated energy shifts and widths of 6 atoms to the [2] J.Dą browski, Int. J. Mod. Phys. E, in press nucleon density distributions in these atoms to gain

8.6 Cross Sections Calculated for Cold Fusion Reactions with Emission of Only One Neutron for Producing the Heaviest Elements by R.SmolaĔ czuk

Entrance-channel effects in cold fusion reactions the level density in the equilibrium configuration and that lead to heavy and superheavy nuclei are discussed that in the saddle-point configuration Comparison of in the framework of the coupled-channels theory [1]. the calculated fusion cross sections with experimental Dynamical deformation besides collective excitations data is given. is taken into account in the entrance channel. The exit channel is described by using the modified statistical [1] R.SmolaĔ czuk, Int. J. Mod. Phys. E 14 No.3 model that takes into account the difference between (2005)373