Superheavy Elements in the Magic Islands

Recent microscopic calculation based on the density functional theory predicts long-lived superheavy elements in a variety of shapes, including spherical, axial and triaxial configurations. Only when N=184 is approached one expects superheavy nuclei that are spherical in their ground states. Magic islands of extra-stability have been predicted to be around Z=114, 124 or, 126 with N=184, and Z=120, with N=172. However, the question of whether the fission-survived superheavy nuclei with high Z and N would live long enough for detection or, undergo alpha-decay in a very short time remains open. In this talk I shall present results of our calculations of alpha-decay half lives of heavy and superheavy nuclei. Calculations, carried out in a WKB framework using density-dependent M3Y interaction, have been found to reproduce the experimental data quite well. Fission survived Sg nuclei with Z=106, N=162 is predicted to have the highest alpha-decay half life (~3.2 hrs) in the Z=106-108, N=160-164 region called, small island/peninsula. Neutron-rich (N >170) superheavy nuclei with Z >118 are found to have half-lives of the order of microseconds or, less.Comment: 9 pages, 1 figure, 1 table; Invited Talk presented at the "Fourth International Conference on Fission and Properties of Neutron-Rich nuclei", held at Sanibel Island, Florida, November 11-17, 200

Superheavy Nuclei to Hypernuclei: A Tribute to Walter Greiner

In nuclear physics, superheavy and hypernuclei are two of the most important fields of research. The prediction of islands of superheavy elements (Z = 114, N = 184, 196 and Z = 164, N = 318) in late sixties by the Frankfurt school played a key role in extending the periodic table of elements up to atomic number 118. Similarly, the demonstration that nuclear matter can be compressed 510 times of its original volume by nuclear shock waves, produced during heavy ion collision, led to the production of singleand double-lambda hypernuclei, as well as anti-matter nuclei. Recent observation of antihypertriton—comprising an antiproton, an antineutron, and an antilambda hyperon, by the STAR collaboration has now made it possible to envision a 3-dimensional nuclear chart of hypernuclei. My own interest in superheavy and hypernuclei was shaped from my first meeting with Walter Greiner at the International Conference on Atomic and Nuclear clusters held at Santorini, Greece in 1993. I will present a brief summary of these exciting developments, including some of our own work. Professor Greiner’s vision, enthusiasm, and encouragement touched many lives and I was one of those privileged ones

A-dependence of ΔΔ-bond and charge symmetry energies

The Δ -bond energies (ΔBΔΔ) of double-Δ hypernuclei provide a measure of the nature of the in-medium strength of the ΔΔ interaction. Likewise, the charge symmetry breaking in mirror nuclei with Δ and ΔΔ is expected to shed light on ΔN and ΔΔN interactions. A generalized mass formula, constructed earlier with broken SU(6) symmetry, is optimized and employed to calculate the separation energies from light to heavy nuclei. The new experimental data on ΔΔ-separation energy of a few double-Δ hypernuclei, and Δ-separation energy of several single-Δ hypernuclei have put more stringent constraint on this mass formula. The ΔBΔΔ values calculated with this optimized formula are in good agreement with the experimental data. This optimized mass formula can be used to predict ΔΔ-bond energy in neutron-rich environment, and to extract Coulomb-corrected symmetry energy from experimental data as well. It suggests existence of bound hypernuclei beyond the normal neutron-drip line

Strangeness physics programs by S-2S at J-PARC

In the K1.8 beam-line at Hadron Experimental Facility of J-PARC, a new magnetic spectrometer S-2S is being installed. S-2S was designed to achieve a high momentum resolution of Δp/p = 6 × 10−4 in FWHM. Several strangeness-physics programs which require the high resolution will be realized by S-2S. The present article introduces J-PARC E70 (missing-mass spectroscopy of Ξ12Be) and E94 (missing-mass spectroscopy of Λ7Li, Λ10B, and Λ12C) experiments