Directed and elliptic flows of neutrons and light charged particles were measured for the reaction 197 Au+ 197 Au at 400 MeV/nucleon incident energy within the ASY-EOS experimental campaign at the GSI laboratory. The detection system consisted of the Large Area Neutron Detector LAND, combined with parts of the CHIMERA multidetector, of the ALADIN Time-of-flight Wall, and of the Washington-University Microball detector. The latter three arrays were used for the event characterization and reaction-plane reconstruction. In addition, an array of triple telescopes, KRATTA, 2 was used for complementary measurements of the isotopic composition and flows of light charged particles.From the comparison of the elliptic flow ratio of neutrons with respect to charged particles with UrQMD predictions, a value γ = 0.72 ± 0.19 is obtained for the power-law coefficient describing the density dependence of the potential part in the parametrization of the symmetry energy. It represents a new and more stringent constraint for the regime of supra-saturation density and confirms, with a considerably smaller uncertainty, the moderately soft to linear density dependence deduced from the earlier FOPI-LAND data. The densities probed are shown to reach beyond twice saturation.

A rotational band with seven gamma-ray transitions between states with spin 2 Planck's constant and 16 Planck's constant has been observed in the doubly magic, self-conjugate nucleus (40)(20)Ca(20). The measured transition quadrupole moment of 1.80(+0.39)(-0.29)eb indicates a superdeformed shape with a deformation beta(2) = 0.59(+0.11)(-0.07). The features of this band are explained by cranked relativistic mean field calculations to arise from an 8-particle 8-hole excitation.

The interaction of an E/A=57.6-MeV 17 Ne beam with a Be target was used to populate levels in 16 Ne following neutron knockout reactions. The decay of 16 Ne states into the three-body 14 O+p+p continuum was observed in the High Resolution Array (HiRA). For the first time for a 2p emitter, correlations between the momenta of the three decay products were measured with sufficient resolution and statistics to allow for an unambiguous demonstration of their dependence on the long-range nature of the Coulomb interaction. Contrary to previous measurements, our measured limit Γ < 80 keV for the intrinsic decay width of the ground state is not in contradiction with the small values (of the order of keV) predicted theoretically.PACS numbers: 25.10.+s, 23.50.+z, 21.60.Gx, 27.20.+n Introduction -Two-proton (2p) radioactivity [1] is the most recently discovered type of radioactive decay. It is a facet of a broader three-body decay phenomenon actively investigated within the last decade [2]. In binary decay, the correlations between the momenta of the two decay products are entirely constrained by energy and momentum conservation. In contrast for three-body decay, the corresponding correlations are also sensitive to the internal nuclear structure of the decaying system and the decay dynamics providing, in principle, another way to constrain this information from experiment. In 2p decay, as the separation between the decay products becomes greater than the range of the nuclear interaction, the subsequent modification of the initial correlations is determined solely by the Coulomb interaction between the decay products. As the range of the Coulomb force is infinite, its long-range contribution to the correlations can be substantial, especially, in heavy 2p emitters.

The transition quadrupole moments Q t for the superdeformed band in 40 Ca have been determined through thin-target Doppler-shift attenuation analyses. A best-fit value of Q t ϭ1.30Ϯ0.05 e b is obtained when a single value is assumed for the entire band. Fitting separate quadrupole moments for in-band transitions decaying from the high-spin states and the presumably admixed low-spin states results in Q t (high)ϭ1.81 Ϫ0.26 ϩ0.41 e b and Q t (low)ϭ1.18 Ϫ0.05 ϩ0.06 e b, respectively. Q t values extracted for individual transitions in a Doppler-broadened line-shape analysis also indicate smaller Q t values at lower spins. These results are consistent with the interpretation of this band as an eight-particle-eight-hole superdeformed band with a significant admixture of less-collective configurations at low spins.

Six superdeformed bands have been found in the nucleus '"Tl. For two of the bands, the dynamic moment of inertia J"' is found to be constant with the rotational frequency Ace, This result can be understood in terms of Pauli blocking of quasiparticle alignments in intruder orbitals, and represents strong experimental evidence that the alignment of these intruders is responsible for the smooth rise in J" seen in other superdeformed nuclei of this mass region.