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

Long-range forces : atmospheric neutrino oscillation at a magnetized detector

Among the combinations $L_e-L_\mu$, $L_e-L_\tau$ and $L_\mu-L_\tau$ any one can be gauged in anomaly free way with the standard model gauge group. The masses of these gauge bosons can be so light that it can induce long-range forces on the Earth due to the electrons in the Sun. This type of forces can be constrained significantly from neutrino oscillation. As the sign of the potential is opposite for neutrinos and antineutrinos, a magnetized iron calorimeter detector (ICAL) would be able to produce strong constraint on it. We have made conservative studies of these long-range forces with atmospheric neutrinos at ICAL considering only the muons of charge current interactions. We find stringent bounds on the couplings \alpha_{e\mu, e\tau} \lapp 1.65 \times 10^{-53} at 3$\sigma$ CL with an exposure of 1 Mton$\cdot$yr if there is no such force. For nonzero input values of the couplings we find that the potential $V_{e\mu}$ opposes and $V_{e\tau}$ helps to discriminate the mass hierarchy. However, both potentials help significantly to discriminate the octant of $\theta_{23}$. The explanation of the anomaly in recent MINOS data (the difference of $\Delta m^2_{32}$ for neutrinos and antineutrinos), using long-range force originated from the mixing of the gauge boson $Z^\prime$ of $L_\mu-L_\tau$ with the standard model gauge boson $Z$, can be tested at ICAL at more than 5$\sigma$ CL. We have also discussed how to disentangle this from the solution with CPT violation using the seasonal change of the distance between the Earth and the Sun.Comment: 9 pages, 3 figures; more explanations on the results are adde

Reply to Comment on Extension of the Bethe-Weizsacker mass formula to light nuclei and some new shell closures

Some properties of the modified Bethe-Weizsacker mass formula (BWM) are discussed. As BWM has no shell effect included, the extra-stability or, magicity in nuclei clearly stands out when experimental mass data are compared with BWM predictions. If the shell effect quenches, the BWM predictions come closer to the experimental data.Comment: 2 pages, no figur